Fermentations

Appl Microbiol Biotechnol, 1992 Jan, 36(4), 440 - 5
Nutritional control of nikkomycin and juglomycin production by Streptomyces tendae in continuous culture; Hege-Treskatis D et al.; Continuous cultures with Streptomyces tendae revealed some interesting facts . In a continuous culture running for more than 2500 h the production of either nikkomycines or juglomycins could be selected by varying the feed composition . Decreasing the phosphate supply in the feed broth from the initial concentration of 2.5 mM to 1.0 mM enhanced the productivity of nikkomycins and decreased the productivity of juglomycins . When switching back to the initial conditions of the experiment after 2000 h nearly the same production behaviour as at the beginning of the fermentation could be observed . This indicated a stable behaviour of the population with regard to nikkomycin productivity . The long continuous fermentation showed the ability of S . tendae Tu 901/8c to produce nikkomycin at a high level for at least 1500 h . In a second continuous culture it was shown that the productivity of the nikkomycins and juglomycins decreased and increased, respectively, with increasing dilution rate . Comparing batch cultures with continuous fermentations, higher juglomycin productivity was found in the latter . These facts indicate that the strain responds to complex interacting physiological controls, by producing either nikkomycins or juglomycins in a higher amount.

J Chem Technol Biotechnol, 1992, 53(4), 397 - 400
Flow injection analysis with immobilized enzymes for process control of pullulan production by fermentation; Englbrecht U et al.; A flow injection system is described for the parallel determination of pullulan and glucose during a fermentation of the fungus Aureobasidium pullulans . The polysaccharide was hydrolyzed by pullulanase and amyloglucosidase, immobilized to controlled-pore glass (CPG) . The glucose produced was oxidized by glucose dehydrogenase and the NADH formed determined photometrically . The pullulan concentration was calculated from the difference to the response obtained for free glucose . The calibration curves for monomer and polymer were both linear between 2 mg dm-3 and 20 mg dm-3 . Analysis of one sample for the determination of glucose and pullulan took about 10 min.

J Chem Technol Biotechnol, 1992, 53(4), 313 - 27
Production of vitamins, coenzymes and related biochemicals by biotechnological processes; Vandamme EJ; Vitamins and related biofactors belong to those few chemicals with a direct positive appeal to people . There is indeed a large need for extra vitamins, other than those derived from plant and animal food sources, due to unbalanced food habits or processing, food shortage or disease . Added vitamins are now either prepared chemically or biotechnologically via fermentation or bioconversion processes . Several vitamins and related biofactors are now only or mainly produced chemically (vitamin A, cholecalciferol (D3), tocopherol (E), vitamin K2, thiamine (B1), niacin (PP or B3), pantothenic acid (B5), pyridoxine (B6), biotin (H or B8), folic acid (B9) or via extraction processes (beta-carotene or provitamin A, provitamin D3, tocopherol, vitamin F-group) . However, for several of these compounds microbiological or algal methods also exist or are rapidly emerging . Others are produced practically exclusively via fermentation (ergosterol or provitamin D2, riboflavin (B2), cyanocobalamin (B12), orotic acid (B13), vitamin F-group, ATP, nucleosides, coenzymes, etc . or via microalgal culture (beta-carotene, E, F) . Both chemical and microbial processes are run industrially for vitamin B2 while vitamin C (ascorbic acid) is produced via a combination of chemical reactions and fermentation processes . A survey is given here of the current state of vitamin production, with emphasis on developments and strategies for improved biotechnological production and its significance, as compared to existing chemical processes . The screening or construction of vitamin hyperproducing microbial strains is a difficult task; pathway elucidation and metabolic (de)regulation need further study; r-DNA technology has only recently been introduced; improved fermentation processes and immobilised biocatalysts bioconversions for the synthesis of chiral vitamin compounds or intermediates or derivatives are gaining importance; the recovery and purification of these vitamin compounds from their fermentation broths remains equally complex.

Biotechnology (N Y), 1992 Jan, 10(1), 60 - 5
Surface-active compounds from microorganisms; Georgiou G et al.; Microbial surfactants are a structurally diverse group of compounds consisting of hydrophilic and hydrophobic domains and which partition preferentially at interfaces . Biosurfactants are of increasing interest commercially as substitutes for synthetic surfactants particularly for environmental applications . This article discusses recent progress in the genetic and biochemical analysis of biosurfactant synthesis as well as the current status of fermentation technologies.

J Chem Technol Biotechnol, 1992, 53(1), 97 - 103
The extraction of penicillin G with aliphatic amines in organic solvents of different polarities; Yang ZF et al.; The equilibrium constants of the extraction, the molar ratios of amines to penicillin G in the extract and the bonding structures of the extracted species were studied with chemical analysis and the absorbance shift of FT-IR spectra of the functional groups in penicillin G . Extraction of penicillin G from the filtrate of fermentation broth indicates that amines will be difficult to use as the industrial solvent for the production of penicillin G because of the poor quality of the final crystalline product obtained and the difficulties involved in the stripping and solvent recovery.

J Ind Microbiol, 1992 Jan, 9(1), 27 - 36
Fate in water of a recombinant Escherichia coli K-12 strain used in the commercial production of bovine somatotropin; Bogosian G et al.; The fate in water of Escherichia coli K-12 strain LBB269, both plasmid-free and carrying the recombinant plasmid pBGH1, was studied . E . coli K-12 strain LBB269 (pBGH1) is a nalidixic acid resistant derivative of W3110G (pBGH1), the microorganism used by Monsanto Company for the commercial production of bovine somatotropin . Water samples were obtained from the Missouri River and from the Monsanto Life Sciences Research Center aqueous waste basin . Strains LBB269 and LBB269 (pBGH1) were grown in fermentation vessel under bovine somatotropin (BST) production conditions, and inoculated into the water samples . The inoculated water samples were incubated at 26 degrees C, and the number of viable E . coli cells was determined as a function of time . In sterile water from both sources, the two strains remained at a constant level for at least 28 days; LBB269 (pBGH1) remained at a constant level in sterile water for at least 300 days . In non-sterile water from both sources, the two strains declined from an initial concentration of about 3.0 x 10(6) cells per ml to less than 10 cells per ml in 147 h . The study conditions did not adversely affect the populations of indigenous microorganisms . The selective loss of strains LBB269 and LBB269 (pBGH1) demonstrates that these E . coli strains do not survive in environmental sources of water . In addition, it was observed that the presence of pBGH1 had essentially no effect on the disappearance of strain LBB269 from either source of water.

Biotechnol Prog, 1992 Jan-Feb, 8(1), 1 - 4
Plasmid stabilization of an Escherichia coli culture through cycling; Stephens ML et al.; The problem of plasmid instability of fermentations that involve plasmid-bearing recombinant organisms is dealt with in this work . Previous theoretical work demonstrated that under certain conditions (where plasmid-bearing species are slower in responding to changes in the fermentation environment than the wild species) the washout of the plasmid-bearing species can be prevented . In the sequel, Weber and San showed that cycling the dilution rate can delay the washout of plasmid-bearing species for a plasmid-bearing Escherichia coli culture . This work shows that it is indeed possible to secure the presence of the plasmid-bearing species at all times through appropriate cycling.

Probl Khig, 1992, 17, 93 - 101
{Body thermal status under low-temperature conditions in brewing production}; Vasileva-Todorova L et al.; The purpose of the present study is to trace the thermal state of workers exposed to low temperatures in brewery production, establishing the heat loss and the stress of thermoregulation . The investigations are performed in the departments for fermentation, deposit, cask washing and filling of 3 brewery plants . In order to characterize the microclimate methods of thermometry, psychometry and catathermometry are used . The heat state is controlled by methods of subjective heat perception, skin temperature, average skin temperature, temperature gradients, oral, rectal and average body temperature and the thermal content . The results of the physiological examinations point out to significant loss, which affects not only the periphery but also the deep tissues . There is an expressed risk of supercooling of the organism . The data of the heat deficit impose a correction of the working clothes and limitation of the exposure.

Arch Tierernahr, 1992, 42(2), 179 - 85
The influence of contamination with separate mycotoxins (aflatoxins, ochratoxin A, citrinin, patulin, penicillic acid or sterigmatocystin) on the in vitro dry matter and organic matter digestibilities of some roughages (berseem hay and wheat straw); Abdelhamid AM et al.; In vitro study on berseem hay and wheat straw was undertaken to investigate the the effect of mycotoxin contamination on dry matter and organic matter digestibilities . The data revealed a negative effect of most studied mycotoxins on the materials digestibility . Among the investigated mycotoxins, penicillic acid with its two concentrations (5 and 10 nmol) was the most negative, affecting digestibilities of both feed materials . Wheat straw digestibility was more influenced than berseem hay by the ochratoxin A, citrinin and sterigmatocystin (besides the penicillic acid) particularly with their high level (10 nmol) . Yet, some mycotoxins act as antibiotics which may affect only the harmful flora but encourage the rumen microflora resulting in slight improvement of digestibility . The rumen conditions were able to metabolize or deform the used levels of all mycotoxins studied . Thus, there were no detectable residues of these mycotoxins in the digestion media after the in vitro fermentation.

Arch Tierernahr, 1992, 42(2), 159 - 69
Influence of yeast (Saccharomyces cerevisiae as Yea-Sacc or Levaferm) on in Sacco dry matter degradability and ruminal parameters of variously fed small ruminants; Flachowsky G et al.; Two series of experiments with rumen fistulated castrated male sheep and goats were carried out . In experiment I three sheep each consumed rations rich in concentrate (700 g concentrate, 200 g chopped wheat straw) or roughage (700 g artificially dried ryegrass, 200 g chopped wheat straw per animal per day) and supplemented with 0, 1, 2 or 4 g Yea-Sacc (Saccharomyces cerevisiae; USA) per sheep per day . In experiment II three sheep were fed with 1000 g artificially dried ryegrass and 200 g concentrate, three goats consumed 750 g ryegrass and 150 g concentrate . 0, 0.5, 1 or 2 g Levaferm (Saccharomyces cerevisiae; Germany) per animal per day were added . Rations of all animals were supplemented with minerals and vitamins . After 14 days of feeding wheat straw, ammonia treated wheat straw and artificially dried grass (exp . I) or wheat straw and artificially dried grass (exp . II) were incubated in nylon bags in the rumen for 6, 12, 24, 48 and 72 hours . At the end of the experiments rumen fluid was taken via cannulae and parameters of rumen fermentation were measured . Higher levels of added Yea-Sacc decreased in sacco dry matter degradability of all incubated feeds . Depression was much higher if Yea-Sacc was added to the concentrate ration (overall mean for 24, 48 and 72 h incubation time: 55.1, 47.1, 46.1 and 44.5 for 0, 1, 2 and 4 g Yea-Sacc) than to the roughage diet (58.7, 56.3, 55.0 and 54.1%) . Levaferm did not significantly influence the rumen dry matter degradability of incubated feeds (overall mean for 24, 48, and 72 h incubation time: 64.0; 64.9; 64.9 and 64.2% for sheep; 63.0; 63.2; 63.2 and 61.6% for goats, if added with 0, 0.5, 1 and 2 g Levaferm per animal per day) . Rumen pH, concentration of volatile fatty acids and molar concentration of fatty acids in rumen fluid were not significantly influenced by added yeasts . More research seems necessary to find out the mode of action of yeast and to quantify and to reproduce the effects of added yeast.

Arch Tierernahr, 1992, 42(2), 153 - 8
Effect of monensin on fermentation of hay and wheat bran investigated by the Rumen Simulation Technique (Rusitec) . 2 . End-products of fermentation and protein synthesis; Jalc D et al.; An experiment was performed with Rumen Simulation Technique (Rusitec) in which the fermentation of mixed ration of hay (12.8 g/d) and wheat bran (3.2 g/d) was compared with the fermentation of the same diet supplemented with 2.5 and 10 mg monensin . The duration of the experiment was 12 days . During the first six days the fermentation conditions in Rusitec were stabilised . The end products of fermentation and indices of protein synthesis were determined . The energy efficiency of volatile fatty acids (VFA), proportion of fermented hexose energy on VFA energy and on energy of bacterial matter were increased in the presence of monensin . The proportion of fermented hexose energy in methane energy was decreased . Utilization of glucose and production of adenosine triphosphate were not affected . The balance of metabolic H2 was reduced and this was manifested in decreasing production, utilization and recovery of metabolic H2 . Microbial efficiency expressed per mol ATP (g/mol) was increased by monensin from 7.8 to 12.6 . The indices of protein synthesis--protein conversion ratio, degradability of protein and microbial protein synthesis efficiency were increased and non protein utilization ratio decreased in the presence of monensin.

Arch Tierernahr, 1992, 42(2), 147 - 52
Effect of monensin on fermentation of hay and wheat bran investigated by the Rumen Simulation Technique (Rusitec) . 1 . Basal parameters of fermentation; Jalc D et al.; An experiment was performed with Rumen Simulation Technique (Rusitec) in which the fermentation of mixed ration of hay (12.8 g/d) and wheat bran (3.2 g/d) was compared with the fermentation of the same diet in the presence of 2, 5 and 10 mg of monensin/d . The duration of the experiment was 12 days . During the first six days the fermentation conditions in Rusitec were stabilized . Monensin significantly depressed the digestibility of dry matter and fibre digestion--neutral detergent fibre (NDF), acid detergent fibre (ADF) and cellulose but only after using 2 mg monensin/d . Addition of monensin depressed the production of VFAs--acetate, butyrate and isovalerate and acetate:propionate ratio . Production of propionate was increased and production of methane and CO2 was decreased in the presence of monensin . It can be explained by changes in the production of VFAs and redistribution of metabolic hydrogen . The recovery of nitrogen was satisfactory (about 100%) and its distribution in the effluent was increased by monensin . The recovery of protein (measured as alpha--NH2 groups) and distribution of protein in the effluent and residues was increased with the increasing dose of monensin.

J Cell Biochem Suppl, 1992, 16G, 151 - 7
Modulation of gene expression as a biomarker in colon; Augenlicht LH et al.; Computer-driven scanning and image processing methodology has demonstrated that genetic inheritance of risk for colorectal cancer in familial polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC) families is associated with highly pleiotropic effects on patterns of gene expression in the flat colonic mucosa . The mitochondrial (mt) gene encoding subunit 3 of cytochrome oxidase (COXIII) is one of a panel of cloned sequences which characterize genetic risk . Expression of COXIII decreased in progression of, and risk for, colonic tumors in vivo . Further, metabolizable, unbranched, short-chain fatty acids (SCFAs) elevated expression of mtCOXIII, as well as mtCOXI, in HT29 cells and also elevated mtCOX enzymatic activity . However, expression of nuclear encoded COX subunits were unaffected . These changes may be related to documented alterations in mitochondria structure and function in transformed colonic epithelial cells . SCFAs produced when colonic microflora causes fermentation of fiber are the principle energy source for normal colonic epithelial cells; SCFAs also induce a more differentiated phenotype both in vitro and in vivo . Therefore, a mechanistic link may exist between molecular events in inherited risk and a dietary factor (fiber) which may modulate such risk . In a preliminary intervention trial in collaboration with M . Lipkin, high risk HNPCC patients received daily supplements of 1500 mg CaCO3 per day, which may be protective for development of colorectal tumors . Elevations in COXIII expression were seen in 7 of 12 patients within the first 7 months, followed by complex changes in expression of this sequence.

Arch Microbiol, 1992, 158(3), 218 - 25
Anaerobic degradation of 1,2-propanediol by a new Desulfovibrio strain and D . alcoholovorans; Ouattara AS et al.; A sulfate-reducing bacterium, strain HDv, was isolated from the anoxic soil of a ricefield using lactate as electron donor . Cells were gram-negative, motile, nonsporulating curved rods, with single polar flagella . Substrates were incompletely oxidized to acetate and included glycerol, 1,2- and 1,3-propanediol . Sulfate, sulfite, thiosulfate, elemental sulfur, fumarate, maleate, and malate were utilized as electron acceptors . Pyruvate, fumarate, maleate, malate and dihydroxyacetone were fermented . Desulfoviridin and c-type cytochromes were present . The DNA base composition was 66.6 +/- 0.3 mol% G+C . The isolate was identified as a Desulfovibrio sp.; its metabolic properties were somewhat different from those of previously described Desulfovibrio species . Comparative biochemical study of 1,2-propanediol dissimilation by the new isolate and Desulfovibrio alcoholovorans showed that NAD-dependent dehydrogenases play a key role in the catabolism of this substrate . The hypothetical pathways of 1,2-propanediol degradation by Desulfovibrio spp . are presented.

Antibiot Khimioter, 1992 Jan, 37(1), 3 - 6
{Effect of penicillin precursors on antibiotic biosynthesis in various strains}; Tikhonova OV et al.; The regularities of biosynthesis of 6-aminopenicillanic acid (6-APA), benzylpenicillin (BP) and phenoxymethylpenicillin (PMP) by the strains under the investigation did not significantly differ . In the absence of the precursor both the strains mainly synthesized 6-APA . Phenylacetic acid (PAA) and phenoxyacetic acid (POAA) provided directed biosynthesis: the fungus synthesized BP or PMP depending on the precursor nature . When the amount of the precursors was not sufficient, 6-APA was synthesized along with the penicillins . PAA proved to be a more active precursor than POAA . When both precursors were present in the fermentation broth, only BR was synthesized . An important distinction of strain 316A was its increased sensitivity to PAA especially in the initial period . After an increase in the PAA concentration the growth rate of strain 316A lowered to a greater extent than that of strain 284A . This was likely to determine the higher levels of penicillin production by strain 316A in the presence of POAA, a nontoxic precursor . A procedure for supplying the precursors was developed . Under the laboratory conditions it provided high levels of the penicillin production.

J Anim Sci, 1992 Jan, 70(1), 296 - 307
In vitro and in vivo studies of factors affecting digestion of feeds in synthetic fiber bags; Marinucci MT et al.; Dry matter disappearance (DMD) and cellulose disappearance (CD) from alfalfa hay were measured simultaneously in synthetic fiber bags incubated in vitro . In general, DMD, CD, and pH were reduced (P less than .05) inside the bags compared with values in the fermentation flasks . Bags became fully expanded with gas soon after the fermentation started, which seemed to inhibit fluid movement into and out of the bag . By creating a vacuum in the flask, fluid exchange was enhanced, and DMD, CD, and pH increased (P less than .01) inside the bags . Sample size, type of fabric, and fabric pore size affected pH, DMD, and CD . Inoculum source (forage or concentrate diet) did not affect DMD in either bags or flasks . In contrast, DMD in bags incubated in vivo was affected (P less than .01) by animal diet . When bags were incubated in vivo inside a rigid plastic container, both pH and DMD were reduced (P less than .01) compared with bags suspended freely in the rumen . Direct physical action of ruminal contents on the bags apparently enhanced exchange of fluid . Bacterial concentrations in bags suspended freely in the rumen were greater than those in bags incubated inside containers . Synthetic fiber bags may be useful in comparing digestibility between diets; however, caution is needed in evaluating such data in absolute terms.

J Antibiot (Tokyo), 1992 Jan, 45(1), 74 - 82
WS-7338, new endothelin receptor antagonists isolated from Streptomyces sp . No . 7338 . I . Taxonomy, fermentation, isolation, physico-chemical properties and biological activities; Miyata S et al.; WS-7338 A, B, C and D, novel endothelin receptor antagonists, have been isolated from fermentation broth of Streptomyces sp . No . 7338 . These antagonists were purified from the culture mycelium by extraction with acetone, followed by carbon column chromatography and HPLC . Among them, WS-7338 B showed good activity in an endothelin receptor binding assay with an IC50 of 2.7 x 10(-7) M.

Plant Foods Hum Nutr, 1992 Jan, 42(1), 25 - 30
Suitability of using sieved or unsieved maize mash for production of "OGI"--a fermented cereal food; Antai SP et al.; Proximate analysis of sieved and unsieved maize mash revealed that there was a decrease in the protein and lipid content of the sieved maize mash as compared to that of the unsieved maize mash . Crude fibre and ash was completely absent in the sieved maize mash, while they were present in the unsieved mash . Chemical analysis of the fermented unsieved maize mash revealed an increase in the protein content from 9.9% (unfermented) to 13.4% after 3 days of fermentation, whereas the protein content of the sieved maize mash increased from 7.1% (unfermented) to 8.4% after the same period of fermentation . Furthermore, the results revealed that the protein content of the fermented unsieved maize mash was 32.1% higher than that of the fermented sieved maize mash indicating that the unsieved maize mash was of a better nutrient quality and should be preferred to sieved maize mash for use in "Ogi" production.

Mol Gen Genet, 1992 Jan, 231(2), 296 - 303
Positive regulation of the LPD1 gene of Saccharomyces cerevisiae by the HAP2/HAP3/HAP4 activation system; Bowman SB et al.; The LPD1 gene of Saccharomyces cerevisiae, encoding lipoamide dehydrogenase (LPDH), is subject to catabolite repression . The promoter of this gene contains a number of motifs for DNA-binding transcriptional activators, including three which show strong sequence homology to the core HAP2/HAP3/HAP4 binding motif . Here we report that transcription of LPD1 requires HAP2, HAP3 and HAP4 for release from glucose repression . In the wild-type strain, specific activity of LPDH was increased 12-fold by growth on lactate, 10-fold on glycerol and four- to five-fold on galactose or raffinose, compared to growth on glucose . In hap2, hap3 and hap4 null mutants, the specific activities of LPDH in cultures grown on galactose and raffinose showed only slight induction above the basal level on glucose medium . Similar results were obtained upon assaying for beta-galactosidase production in wild-type, or hap2, hap3 or hap4 mutant strains carrying a single copy of the LPD1 promoter fused in frame to the lacZ gene of Escherichia coli and integrated at the URA3 locus . Transcript analysis in wild-type and hap2 mutants confirmed that the HAP2 protein regulates LPD1 expression at the level of transcription in the same way as it does for the CYC1 gene . Site-directed mutagenesis of the putative HAP2/HAP3/HAP4 binding site at -204 relative to the ATG start codon showed that this element was required for full derepression of the LPD1 gene on non-fermentable substrates.

J Clin Microbiol, 1992 Jan, 30(1), 245 - 8
Selective detection of Mycoplasma fermentans by polymerase chain reaction and by using a nucleotide sequence within the insertion sequence-like element; Wang RY et al.; A new assay using the polymerase chain reaction to amplify a 206-nucleotide specific gene sequence within the insertion sequence-like element of Mycoplasma fermentans has been developed . The unique insertion sequence-like element exists in multiple copies in the M . fermentans genome . The assay selectively amplifies DNA from all strains of M . fermentans tested . In contrast, DNA from other species of human and nonhuman mycoplasmas, common tissue culture-contaminating mycoplasmas, and bacteria, as well as human, monkey, and mouse tissues do not produce the amplified DNA products specific for M . fermentans.

Am J Gastroenterol, 1992 Jan, 87(1), 48 - 54
Effect of dietary fiber on total carbohydrate losses in ileostomy effluent; Steinhart AH et al.; Studies were performed in three ileostomate subjects to determine the effect of intake of various carbohydrate-containing foods on the ileostomy losses of macronutrients . The percent recovery of available carbohydrate in ileostomy effluent varied between 1.09% and 22.63% for the various foods . Available carbohydrate recovery (%) was positively correlated with fiber (r = 0.91) and protein (r = 0.46) intake, but negatively with available carbohydrate intake (r = -0.66) . Stepwise regression indicated that dietary fiber intake was the principal factor determining the amount of available carbohydrate in ileostomy effluent . Fiber intake was negatively correlated with water concentration of the effluent (r = -0.61) . This study demonstrates that although fiber has been considered the chief substrate available for colonic fermentation, as the fiber intake increases, so the total fermentable load entering the colon is likely to increase due to losses of available carbohydrates in addition to fiber . Simple assessment of dietary fiber is likely to grossly underestimate the fermentable load on high-fiber, high-carbohydrate diets.

Medicina (B Aires), 1992, 52(2), 103 - 8
Relationship between enterotoxigenic Escherichia coli and diarrhea among children in Buenos Aires; Binsztein N et al.; The incidence of enterotoxigenic Escherichia coli (ETEC) has been studied in 85 children with acute diarrhea in patients in the Hospital de Ninos Pedro de Elizalde, Buenos Aires, and in 38 healthy children . All of them were up to four years old and none had received antibiotic treatment within 7 days before sampling . ETEC was recovered in 9 out of 85 (10.6%) children with diarrhea . From these positive cases, 6 were associated with heat-stable (ST), 1 with heat-labile (LT) and 2 with both LT and ST enterotoxins . Only one case (2.6%) of LT-producing ETEC was detected in the control group . In 5 out of 9 ETEC diarrhea cases (55.5%) the isolated strains expressed human colonization factor antigens (CFA); four of them were CFA/I and one CFA/II . The characteristics of the CFA, biotype, serotype and antibiotic sensitivity pattern were studied in 23 E . coli isolates from 10 ETEC positive children . Of the 12 ST only strains, 5 (41.7%) expressed CFA/I and 2 (16.7%) CFA/II (CS2 + CS3) . One out of 2 LT/ST strains expressed CFA/I . CFAs were not detected in the ETEC-LT nor in the toxin negative E . coli strains . From the ETEC isolated, 82.4% were resistant to 4 or more antibiotics, whereas only 50% of simultaneously isolated toxin-negative E . coli presented this sensitivity pattern . The different ETEC strains belonged to several different serotypes, some of them rarely observed in other countries . None of these serotypes correlated either with the toxin profile or with the sugar fermentation pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Rocz Panstw Zakl Hig, 1992, 43(3-4), 253 - 8
{Effect of the fermentation process on levels of nitrates and nitrites in selected vegetables}; Herod-Leszczynska T et al.; The aim of this study was to follow the changes in the levels of nitrates and nitrites throughout the process of fermentation of sauerkraut from white and red cabbage and red beets . The nitrate and nitrite levels were determined in raw and fermentation as well as in red beets and "beet acid" after a week of souring . Nitrate were determined by the brucine method, while nitrates by the Griess colorimetric method . Mean reduction of nitrates in sauerkraut (in relation to raw cabbage) was ca . 55.5% and that of nitrites ca . 76.7% . In the red sour cabbage a decrease in the level of nitrates in relation to the product by ca . 84.1% and in that of nitrites by ca . 67.4% was found . The stabilization of both nitrate levels in both kinds of cabbages followed as after the second month of storage, as confirmed by statistical analysis of the results . In the red beets after the process of fermentation a decrease in the level of nitrates by ca . 91.6% was noted . An undefined portion of the studied compounds passed into the liquid . The "beet acid" contained 595.9 mg/dm1 of nitrates and 3.26 mg/dm3 of nitrites.

Arch Vet Pol, 1992, 32(1-2), 101 - 7
Changes of energetic value and protein level of rumen content in sheep fed with stuff with livex and blood meal supplementation; Zawadzki W et al.; The aim of studies was to determine the influence of Wroclaw product from blood--brown, dried livex (modified by whey) and blood meal, which were added to sheep forage, on energetic value and protein, also volatile fatty acids (VFA) levels in rumen content of these animals . The samples of rumen content for determination of the three parameters mentioned above were taken 2.5 hrs after finished morning feeding . The addition of livex and blood meal to forage was 2% . When two non-conventional diet supplements were used in vivo, there was observed significant inhibitory influence of livex on methane level among rumen gases, amounting to 38.9% in sheep and increase in protein amount of about 25.92% (for blood meal these values were: 5.6% and 7.4%, respectively) . In connection with that, energy of rumen content was higher by about 22.22% in group of sheep fed with stuff with livex addition and by about 7.41% in group fed forage with blood meal addition . The using of livex as an addition to fodder caused increase of the rumen fermentation efficiency and also regulation of non-glucogenic ratio of volatile fatty acids.

Yi Chuan Xue Bao, 1992, 19(6), 541 - 8
{Study on the meiotic mapping and functions of another new osmotic-sensitive gene-osm3 in Saccharomyces cerevisiae}; Zhi H et al.; Another recessive nuclear gene mutation of Sacchromyces cerevisiae, osm3, which causes growth inhibition on hypertonic media, has been mapped on the chromosome II by tetrad analysis . Its second-division segregation frequency is about 51.01%, and the map distances between osm3 and the centromere of chromosome II is about 25.51 centimorgans and it is approximately 45 centimorgans far gene gall . The studies on the reverse mutation of osm3 indicated that this osmotic-sensitivity arises from a missense or nonsense mutation in OSM3 locus . The response of yeast to osmotic stress and the mechanism of osm3 gene function were investigated . The results indicated that high intracellular glycerol content is necessary for yeast to grow in hypertonic media; The gene product of osm3 is probably relative to the process of glycerol transportation . Finally, the effect of osmotic stress on fermentability was also discussed.

Braz J Med Biol Res, 1992, 25(1), 35 - 7
Voluntary intake of "Tiquira", an alcoholic beverage prepared from fermented manioc, decreases immunoglobulin production and increases self-reactivity in mice; Nascimento FR et al.; We studied the effects of chronic voluntary ingestion of "Tiquira" (50%)--an alcoholic beverage prepared from fermented manioc, widely consumed in Maranhao,--on the natural immunological activity of young adult (2-3 months old) C57B1/6J mice (16-17 g) by evaluating the number of plaque-forming cells (PFCs) in the spleen and by titrating serum antibodies by ELISA . Voluntary ingestion of "Tiquira" for 30 days decreased immunoglobulin secretion in serum (Control: 1600 +/- 30 vs Experimental: 193 +/- 20), caused an impressive reduction in the total number of PFCs in the spleen (Control: 482 +/- 22 vs Experimental: 58 +/- 3) and increased the proportion of self-reacting antibody molecules in serum (Control: 119 +/- 16 vs Experimental: 800 +/- 20) and self-reactive PFCs to mouse red blood cells (MRBC) in the spleen (Control: 183 +/- 14 vs Experimental: 272 +/- 16; N = 10 animals per group) . These preliminary results suggest that the voluntary ingestion of "Tiquira" for 30 days may interfere with immunological relations by decreasing the total number of immunoglobulin secreting cells and increasing the anti-self antibody production . Experiments are in progress to determine if ethanol or other substances present in "Tiquira" are responsible for the effects documented here.

Ciba Found Symp, 1992, 171, 129 - 37; discussion 137-43
Regulation of gibberellin formation by the fungus Gibberella fujikuroi; Bruckner B; Gibberellins are a classic example of the production of plant growth regulators by microorganisms . They are important biotechnological products and are increasingly used in agriculture and horticulture . The economic importance of these plant hormones has led to an extensive study of the regulation of gibberellin biosynthesis . There have been reports of light, growth rate, inoculum size and carbon and ammonium sources acting as regulators of gibberellic acid biosynthesis . Besides light stimulation, nitrogen repression is a well-known regulatory principle of secondary metabolite formation . In Gibberella fujikuroi ammonium interferes with the production of gibberellic acid whereas phosphate does not influence the biosynthesis . It was found that the negative effect of ammonium ions is due to both the inhibition of activity and the repression of de novo synthesis of specific gibberellin-producing enzymes . Besides nitrogen control, the biosynthesis of gibberellins is suppressed by glucose . This glucose effect can be overcome by the addition of mevalonic acid . Therefore, the key enzyme of the isoprenoid pathway, the HMG-CoA reductase, seems to be the target of C-catabolite repression . A detailed knowledge of the regulation of gibberellin biosynthesis is important for fermentation processes . The biological function of gibberellin formation for the producing fungus is discussed.

Chin J Biotechnol, 1992, 8(2), 99 - 106
Construction of a genetically engineered strain producing propionylspiramycin; Li Y et al.; Our work has demonstrated the cloning of propionyl acylase gene and the expression of S . mycarofaciens mutant in S . lividans TK54 . In this paper, we report the transformation of pIJM9 recombinant plasmid containing the propionyl acylase gene into spiramycin producer S . spiramyceticus . The results of colony hybridization and Southern hybridization showed that No . 61 transformant harbored the pIJM9 recombinant plasmid . TLC and bioautography showed that the Rf value of one component of the fermentation products of No . 61 transformant was similar to that of propionylspiramycin . The HPLC retention time of the components of the fermentation products of No . 61 transformant and that of propionylspiramycin were also similar . Mass spectrum analysis showed that there was propionylspiramycin II in the fermentation products of No . 61 transformant . According to these results, No . 61 transformant is shown to be a genetic engineered strain producing propionylspiramycin.

Folia Microbiol (Praha), 1992, 37(6), 433 - 41
Citric acid production by Aspergillus niger using media containing low concentrations of glucose or corn starch; Nguyen TK et al.; By using an appropriate ratio of carbon source to mineral components, we obtained comparable citrate yields in media containing different concentrations of glucose . The enzyme system of inoculum passed on gradually from "growth" state to "production" state during the mould growth . In the starch medium, the critical factors of citric acid production are the aeration efficiency of the medium and the amylase formation of the strain . The air interruption exhibited a prolonged inhibition of the production rate but not of the citrate yield in glucose medium while those parameters in starch medium containing excessive urea were briefly but severely inhibited . After being affected by these unfavorable conditions, the production activity of Aspergillus niger could be restored by applying an appropriate fermentation process.

Chin J Biotechnol, 1992, 8(3), 195 - 201
Studies on kinetic model of vitamin C two-step fermentation process; Wei D et al.; This paper aims at analyzing the bioconversion process from L-sorbose to 2-Keto-L-gulonic acid with the aid of the growth factor assumption . Fermentation mechanism is discussed after making necessary simplifications . A model is established for this second step fermentation process . Nonlinear optimization together with Runge-Kutta method, are used to obtain model parameters . Results of computer simulation agree with experimental data to show the reliability of the kinetic model.

Chin J Biotechnol, 1992, 8(3), 171 - 8
Utilization of the protoplast fusion technique to explore directional altering lincomycin producing microorganism; Xu J et al.; Interspecific protoplast fusion between Streptomyces lincolnensis var . lincolnensis (LM gamma, CTC gamma, producing lincomycin) protoplast and Streptomyces aureofaciens (LM gamma, CTC gamma, producing chlorotetracycline) protpolast which had been treated with UV radiation 40 min for inactivation was performed with PEG 6000, the fusants were obtained by directly selecting from the regeneration plates containing CTC 50 micrograms/ml, the fusion frequency was about 9.05 x 10(-5) . From many fusants, only 4 stable recombinants were obtained . These species produced antibiotics which are different from lincomycin and chlorotetracycline . Preliminary identification of the antibiotic synthesized by one of the recombinants suggests that its basic structure might be similar to that of lincomycin . The fermentation product of recombinant No . 2 showed new chromatographic spot which is similar to that of clindamycin . Though the products remain to be identified further, this strategy seems to be worthy of exploring for screening new antibiotics.

Vestn Ross Akad Med Nauk, 1992, (9-10), 41 - 3
{Detection of Mycoplasma and its antibodies in the blood of HIV-positive patients and in healthy persons}; Rakovskaia IV et al.; The comparative study of HIV-positive and clinically healthy persons has indicated that the antigens of M . pneumoniae, M . fermentans and U . urealyticum are encountered nearly twice more frequently in the blood of HIV-infected patients than in that of healthy individuals . Mycoplasma antibodies are detected in HIV-positive persons 12 times more frequently than in healthy ones . Among the HIV-infected persons there are those who have simultaneously antigens of some Mycoplasma species.

J Cardiovasc Pharmacol, 1992, 20 Suppl 12, S11 - 4
In vitro biological profile of a highly potent novel endothelin (ET) antagonist BQ-123 selective for the ETA receptor; Ihara M et al.; The novel endothelin (ET) receptor antagonists BE-18257A and BE-18257B were isolated from the fermentation products of Streptomyces misakiensis . The above-mentioned compounds inhibited {125I}ET-1 binding to ETA receptors (selective for ET-1) on porcine aortic vascular smooth muscle cells (VSMCs) with IC50 values of 1.4 and 0.47 microM, respectively . {125I}ET-1 binding to ETB receptors (nonselective to ET isopeptides) in cerebellar membranes was not inhibited by either of these compounds even at 100 microM . The synthesized analogue BQ-123 induced extremely potent inhibition of {125I}ET-1 binding to ETA receptors (IC50 of 7.3 nM), but it barely inhibited {125I}ET-1 binding to ETB receptors (IC50 of 18 microM) and binding of various other peptides to their receptors . BQ-123 shifted the concentration-response curve for ET-1 toward the right in porcine isolated coronary arteries, indicative of competitive antagonism for the ETA receptor . However, there was a small amount of BQ-123-insensitive vasoconstriction that paralleled the incomplete inhibition of {125I}ET-1 binding in the membrane of the vascular smooth muscle layer . These data suggest that the artery contracts via both ETA and ETB receptors and that BQ-123 selectively inhibits ETA-mediated contraction . Furthermore, BQ-123 revealed large tissue and species differences in the distribution of ETA receptors . Thus, the potent ETA antagonist BQ-123 should be useful in clarifying the (patho)physiological roles of ETA receptors.

J Comp Physiol {B}, 1992, 162(7), 637 - 45
Relationships between plasma composition and parotid salivary composition and secretion rates in the potoroine marsupials, Aepyprymnus rufescens and Potorous tridactylus; Beal AM; Parotid salivation was investigated in two species of potoroine marsupial, Aepyprymnus rufescens and Potorous tridactylus to ascertain flow rates and composition, the buffer capacity of the saliva with respect to possible dependence of these animals on foregut fermentation, and the similarity of anion excretion patterns to those of the kangaroo parotid . Under anaesthesia neither species secreted spontaneously and secretion was stimulated by intravenous infusion of carbachol, bethanechol and isoprenaline . Under cholinergic stimulation in Aepyprymnus, the concentrations of Na, Cl, HCO3 and osmolality were positively correlated with flow rate, whereas K, Mg, PO4, H+ and urea were negatively correlated with flow . Amylase activity and the concentrations of protein and Ca showed no consistent relation to flow . Relative to Aepyprymnus, saliva of Potorous had much lower amylase activity and amylase activity per gram protein, lower concentrations of urea and Ca, and higher Na . Protein, K and HCO3 concentrations were similar in both species . The plasma of both species had similar electrolyte concentrations, but Potorous had lower protein, urea, osmolality and amylase activity . Plasma amylase activity in Aepyprymnus rose during cholinergic stimulation to levels in excess of rodent plasma . Isoprenaline infusion in Aepyprymnus increased salivary amylase activity and concentrations of protein, Ca, HCO3 and PO4, and reduced the concentrations of Cl and H+ . The patterns of anion excretion in the two potoroine marsupials were dissimilar to those of the kangaroo parotid suggesting that parotid fluid secretion is not HCO3 driven to the same extent as that of Kangaroos . Buffer anion concentrations and secretion rates were similar to koalas and low relative to kangaroos, indicating that these potoroines do not rely on foregut fermentation.

Ann N Y Acad Sci, 1991 Dec 27, 646, 259 - 72
Study of high density Escherichia coli fermentation for production of porcine somatotropin protein; Chang LL et al.; Recombinant E . coli strains and culture conditions were studied for the fermentation expression of porcine somatotropin (PST) inclusion bodies under the control of a pL promoter . Our objective was to achieve high cell density together with a high level of recombinant protein expression . Improved fermentation conditions included oxygen enrichment, yeast extract (YE) effect, optimal specific growth to switch on gene expression, and feeding strategies . To maintain a low residual glucose concentration, a medium feed rate was controlled on a real-time basis by using cell density information estimated from on-line carbon dioxide monitoring of a fermentor's exhaust gas . The optimal specific growth rate required to initiate a temperature shift in our system was found to be around 0.2 hr-1 . The cell density and PST expression level could reach 55 OD600 and 35%, respectively, after 16 hours of cultivation under optimal conditions by applying computer-controlled nutrient feed . In our recombinant host/vector system, the location of cl gene appears to affect gene expression under YE-supplemented and/or a high cell density culture condition . With cl gene placed on plasmid, our E . coli host no longer showed sensitivity toward YE in PST gene expression.

FEBS Lett, 1991 Dec 16, 295(1-3), 223 - 6
The proton pump bacteriorhodopsin is a photoreceptor for signal transduction in Halobacterium halobium; Bibikov SI et al.; Halobacterium halobium swims by rotating its polarly inserted flagellar bundle . The cells are attracted by green-to-orange light which they can use for photophosphorylation but flee damaging blue or ultraviolet light . It is generally believed that this kind of 'colour vision' is achieved by the combined action of two photoreceptor proteins, sensory rhodopsins-I and -II, that switch in the light the rotational sense of the bundle and in consequence the swimming direction of a cell . By expressing the bacteriorhodopsin gene in a photoreceptor-negative background we have now demonstrated the existence of a proton-motive force sensor (protometer) and the function of bacteriorhodopsin as an additional photoreceptor covering the high intensity range . When the bacteriorhodopsin-generated proton-motive force drops caused by a sudden decrease in light intensity, the cells respond by reversing their swimming direction . This response does not occur when the proton-motive force is saturated by respiration or fermentation.

S Afr Med J, 1991 Dec 7, 80(11-12), 543 - 5
Malabsorption of carbohydrate foods by urban blacks; Segal I et al.; Prevalences of non-infective bowel diseases are very low in South African urban blacks compared with the white population . In seeking elucidation, using breath hydrogen measurements in series of black and white subjects, small-bowel transit time was determined, and the malabsorption of maize, wheat, and rice investigated . Median transit times in both ethnic groups were similar . Rice was fully, but wheat incompletely absorbed by both groups . Maize, the staple food of blacks, was incompletely absorbed by them, although completely absorbed by the white subjects . Carbohydrate consumption is high in the black population (60-65% of total energy intake) . It is probable that in blacks, despite their now eating a low-fibre diet, an expected increase in large-bowel diseases has been inhibited in part by the protective mechanism of fermentation of malabsorbed maize and wheat.

FEBS Lett, 1991 Dec 2, 294(1-2), 35 - 7
Turnover of the K+ transport system in Saccharomyces cerevisiae; Benito B et al.; The stability of the K+ transport system in Saccharomyces cerevisiae has been studied upon inhibition of protein synthesis with cycloheximide . Addition of the antibiotic gave rise to an inactivation of this transport . This activation followed first-order kinetics and was stimulated by the presence of a fermentable substrate . A half-life of about 4 h could be calculated in the presence of glucose . The results indicate that, similarly to sugar carriers, K+ transport system is less stable than the bulk of proteins of this organism.

J Am Diet Assoc, 1991 Dec, 91(12), 1567 - 71
Dietary treatment of lactose intolerance in infants and children; Sinden AA et al.; During the past several years there have been many reports of alternative dietary therapies for primary and secondary lactose intolerance . We have learned that it is useful to feed through most episodes of mild diarrhea that previously would have been treated with clear liquid diets . Infant formulas, including both soy-protein and hydrolysate formulas with specially designed carbohydrate, protein, and fat components, are available to treat the infant with diarrheal syndromes and secondary lactase deficiency . Also, the diet can be supplemented with lactase . Specialized lactose-reduced products as well as cultured and fermented dairy products may be used in varying degrees for lactose-intolerant children . The ingestion of milk with food and fiber components in the diet has also been shown to improve symptoms of lactose intolerance . This review summarizes the essentials of diagnosis of and dietary therapy for lactose intolerance . Our findings indicate that a number of specialized formulas and products are available for successful dietary management of lactose intolerance in infants and children.

Infect Immun, 1991 Dec, 59(12), 4547 - 54
Sugar metabolism by fusobacteria: regulation of transport, phosphorylation, and polymer formation by Fusobacterium mortiferum ATCC 25557; Robrish SA et al.; Strains of eight Fusobacterium species differed in the ability to use sugars as energy sources for growth . For Fusobacterium russii ATCC 25533, F . gonidiaformans ATCC 25563, and F . nucleatum ATCC 10953 (except for fructose), growth was marginal to poor on all of the sugars tested . Other species displayed reasonable growth on glucose, fructose, mannose, and galactose, and two strains of F . mortiferum (ATCC 25557 and ATCC 9817) grew well on six of the sugars tested, including sucrose and maltose . Glucose transport by resting cells of most of the species was dependent upon (or markedly stimulated by) the presence of a fermentable amino acid . By contrast, F . mortiferum cells rapidly accumulated glucose and other sugars in the absence of amino acids . Although these cells were constitutive for glucose uptake, accumulation of other sugars was specifically induced by growth of F . mortiferum on the appropriate sugar . Spectrophotometric analyses and in situ staining of anionic polyacrylamide gels showed that glucose and fructose (mannose) are phosphorylated by separate ATP-dependent kinases . Fructokinase was stable in air at 4 degrees C, but under these conditions, greater than 70% of the glucokinase activity was lost . After overnight dialysis of the extract, no glucokinase activity was detectable; however, 65% of the initial enzyme activity was retained by inclusion of 1 mM dithiothreitol in the dialysis buffer . Thin-section electron microscopy showed that cells of F . mortiferum produced various amounts of intracellular glycogen during growth on the following sugars (in decreasing order of formation): galactose greater than sucrose greater than glucose greater than mannose greater than fructose . Mechanisms for sugar transport regulation, phosphorylation, and polymer synthesis by F . mortiferum cells are proposed.

Antibiot Khimioter, 1991 Dec, 36(12), 3 - 6
{Effect of the methods of sterilization on the quality of nutrient media and on the level of antibiotic production}; Motina GL et al.; It was shown that conditions for heat sterilization of nutrient media for biosynthesis of antibiotics had an impact on their biochemical composition and activity of a fermentation broth in production of penicillin and erythromycin . The temperature of 120 degrees C and the time of 25 minutes proved to be optimal for sterilization of the media in regard to both preservation of their biochemical composition and providing of the maximum antibiotic productivity on the one hand and maintenance of the sterility during the fermentation process on the other hand.

J Anim Sci, 1991 Dec, 69(12), 4974 - 82
Influence of source and level of ruminal-escape lipid in supplements on forage intake, digestibility, digesta flow, and fermentation characteristics in beef cattle; Hightshoe RB et al.; Six ruminally fistulated steers (550 kg) and 24 heifers (315 kg) were used to determine the effect of source and amount of ruminal-escape lipid in a supplement on forage intake and digestion . Steers were used in a 6 x 6 Latin square digestion study to evaluate six supplementation treatments: 1) negative control (NC), no supplement; 2) positive control (PC), soybean meal:grain sorghum supplement; 3) low-Megalac (calcium salts of fatty acids; LM) supplement; 4) high-Megalac (HM) supplement; 5) low-Alifet (crystallized natural animal fat, LA) supplement; and 6) high-Alifet (HA) supplement . Supplements were fed at .30% of BW on a DM basis and were isoenergetic within fat levels (high vs low) . Steers were fed mature brome hay (7.2% CP) at 1.5% of BW on a DM basis . In the forage intake trial, heifers were assigned randomly to the same supplement treatments . Prairie hay (4.4% CP) was offered at 130% of ad libitum intake . Dry matter and NDF digestibility, ruminal DM fill, indigestible ADF passage rate, and fluid dilution and flow rates were not different (P greater than .10) among treatments . Total VFA concentrations were greater (P less than .01) and acetate-to-propionate ratio (Ac:Pr) was less (P less than .01) in supplemented groups; however, neither source nor level of escape lipid influenced either total VFA or Ac:Pr . Forage intake was greater (P less than .01) for supplemented groups than for the NC . At the high level of fat inclusion, heifers supplemented with Alifet ate slightly more (P less than .05) forage than those supplemented with Megalac.(ABSTRACT TRUNCATED AT 250 WORDS)

J Anim Sci, 1991 Dec, 69(12), 4726 - 33
Comparative feeding value of tapioca pellets for feedlot cattle; Zinn RA et al.; A feedlot growth-performance trial and a metabolism trial were conducted to evaluate the comparative feeding value of tapioca pellets (TP) . In the growth-performance trial treatments consisted of a steam-flaked corn (SFC)-based finishing diet in which a blend of 86% TP and 14% peanut meal replaced SFC at the rate of 0, 15, or 30% of diet DM . Daily weight gain (P less than .10) and DM intake (P less than .01) were greatest when 15% of the diet DM consisted of TP . Feed/gain increased linearly (P less than .01) with TP substitution into the diet . Treatment effects on carcass merit were small (P greater than .10), except that marbling score was greater with 15% TP than with either 0 or 30% TP . In the metabolism trial involving four Holstein steers, treatments consisted of an 88% concentrate diet containing 67% of either SFC or TP . Ruminal and total tract digestibility of starch was similar (P greater than .10) for SFC and TP, averaging 91 and 99%, respectively . Postruminal (P less than .05) and total tract (P less than .01) digestibility of N was lower for the TP than for the SFC diet . Total tract digestibility of N in TP was 3% . Little, if any, ADF in TP was fermented in the rumen . Total tract digestibility of ADF in TP was 16% . Total tract digestibility of DM (P less than .01) and OM (P less than .05) decreased 7 and 5%, respectively, with TP substitution for SFC . Virtually all the difference in OM digestibility could be attributed to differences in ADF excretion . The DE value of the diet decreased 11.5% (P less than .01) with the substitution of TP for SFC . It was concluded that TP can replace up to 30% of the DM in growing-finishing diets without adversely affecting ADG or DM intake of feedlot cattle . Tapioca pellets have approximately 86% the NE value of SFC.

Cent Afr J Med, 1991 Dec, 37(12), 397 - 403
Infection after Harare valve V-P shunt operations: a review of 92 cases; Sibanda EN et al.; Case files of 92 patients who had their hydrocephalus relieved by the insertion of the Harare Valve shunt system were reviewed . All patients had undergone surgery for shunt insertion at the Harare Central and Parirenyatwa Teaching Hospitals in Harare, Zimbabwe, between January 1986 and January 1988 . All but one patient reviewed had Harare valve ventriculoperitoneal shunt insertions . The commonest indication for shunt insertion was congenital hydrocephalus alone or coexisting with other abnormalities (62 pc) . Post meningitic hydrocephalus and hydrocephalus associated with intracranial tumours were next in frequency at 26 pc and 9 pc respectively . The etiology of hydrocephalus was not diagnosed in one four-year-old patient . The ages of the patients on admission ranged from one day to seven years (mean 12.4 months) . Infection rates correlated well with the etiology of hydrocephalus; lowest (2 and half pc) in patients with simple congenital hydrocephalus and highest (29.2 pc) in post meningitic patients . A variety of organisms were isolated from CSF, blood, wounds and catheter tips . Lactose fermenting coliforms, S . epidermidis and E . coli predominated . Infection was combated by antibiotics, shunt removal or a combination of both . The antibiotics most commonly used were the penicillins, chloramphenicol, cloxacillin and gentamycin.

Z Lebensm Unters Forsch, 1991 Dec, 193(6), 538 - 40
Changes in benzo(a)pyrene content in fermented salami; Simko P et al.; The benzo(a)pyrene (BaP) content of fermented salami was monitored during the technological processes of cold smoking, ripening and storage . The changes in BaP content were not so great as in products smoked with hot smoke . However, the decrease in BaP content caused by destructive action of physico-chemical environmental factors was compensated by successive dehydration of the fermented product . After recalculating the BaP content on a dry weight basis a concentration decrease was evident . Significant changes were registered during smoking and ripening while storage under different conditions caused no further effect on these changes.

J Dairy Sci, 1991 Dec, 74(12), 4326 - 36
Performance and ruminal function development of young calves fed diets with Aspergillus oryzae fermentation extract; Beharka AA et al.; Neonatal Holstein heifer (n = 72) and bull (n = 40) calves were used to study the effects of Aspergillus oryzae fermentation extract (Amaferm) on their performance and on rumen development . The starter diets were formulated to achieve Amaferm consumption of 0, .5, 1, or 3 g per calf daily . Calves were fed milk daily and allowed to consume starter and a mixture of alfalfa and bromegrass hay ad libitum . Weaning was when calves consumed 550 g of starter on 2 consecutive d . Weight gain and feed consumption were recorded weekly . Forty of the heifer calves, 10 from each treatment, were selected randomly to study the effects of Amaferm on ruminal fermentative development . Ruminal fluid samples were collected for pH, ruminal fermentation products, and for bacterial enumerations . Overall, Amaferm-supplemented calves were weaned 1 wk earlier than unsupplemented calves . They had higher total VFA, propionate, and acetate concentrations in the rumen than unsupplemented calves . Total anaerobic, hemicellulolytic, and pectinolytic bacterial counts were higher; cellulolytic bacterial counts tended to be higher for the Amaferm-supplemented calves than for controls . In general, Amaferm-supplemented calves had greater ruminal microbial activity than those not fed Amaferm.

Appl Environ Microbiol, 1991 Dec, 57(12), 3660 - 3
Bacteriophages from the forestomachs of Australian marsupials; Klieve AV; Bacteriophages were observed in forestomach contents from three species of Australian macropodoid marsupials possessing a foregut fermentative digestion: the eastern grey kangaroo (Macropus giganteus), the eastern wallaroo (Macropus robustus robustus), and the rufous bettong (Aepyprymnus rufescens) . Forty-six morphologically distinct phage types, representing the families Myoviridae, Siphoviridae, and Podoviridae, were identified . The range of forms varied between host species . The greatest diversity of phage types was found in forestomach contents of the wallaroo, and few phage types were recorded from the rufous bettongs . It is concluded that macropodoid marsupials, in common with their eutherian counterparts, possess diverse populations of bacteriophages in their fermentative forestomachs.

Appl Environ Microbiol, 1991 Dec, 57(12), 3415 - 7
Effect of benzoic acid on glycolytic metabolite levels and intracellular pH in Saccharomyces cerevisiae; Warth AD; Low concentrations of benzoic acid stimulated fermentation rates in Saccharomyces cerevisiae . At concentrations near the maximum permitting growth, there was inhibition of fermentation, lowered ATP and intracellular pH, and relatively greater accumulation of benzoate . Changes in the levels of glycolytic intermediates suggested that fermentation was inhibited as a result of high ATP usage rather than of lowered intracellular pH . Specific inhibition of phosphofructokinase or of several other glycolytic enzymes was not observed.

J Parasitol, 1991 Dec, 77(6), 874 - 83
Water balance and its relation to fermentation acid production in the intestinal parasites Hymenolepis diminuta (Cestoda) and Moniliformis moniliformis (Acanthocephala); Uglem GL; Water balance and its relation to carbohydrate metabolism was examined in Hymenolepis diminuta in parallel with the putative osmoconformer Moniliformis moniliformis . Worms were removed from rat intestines, weighed, and incubated (37 C) 1 hr in rat serum and various salines, some with mannitol to vary osmotic concentration from 150 to 400 mOsm/L . Worms were removed at 15-min intervals, weighed, and returned to the test solution . Rat serum and a Ringer's saline (pH 7.4 and 300 mOsm/L) with or without 5 mM glucose were isotonic to M . moniliformis, which behaved like an osmometer, shrinking, or swelling in proportion to external osmotic changes . Hymenolepis diminuta rapidly lost 20-25% wet weight in these solutions and regained lost water when 5 mM glucose was added to the saline . Tapeworms maintained constant body weight between 210 and 335 mOsm/L, but they rapidly gained or lost water outside of this range . Glucose metabolism and uptake of {3H}glucose from the medium increased progressively between 210 and 310 mOsm/L, whereas uptake rates of {3H}leucine, 22Na+, and 36Cl- were not affected . Unbuffered saline (initial pH 6.5 and 300 mOsm/L) had a lower pH (5.0) and higher osmolality (307 mOsm/L) after a 1-hr incubation with tapeworms . Such saline was less hypertonic than unconditioned saline to freshly obtained worms . A Ringer's saline (300 mOsm/L) containing 50 mM acetate- was also hypertonic (greater than 20% weight loss) to tapeworms at pH 7.4, but it was hypotonic (greater than 20% weight gain) at pH 5.0 . Isotonicity at 300 mOsm/L was achieved with pH 5.0 and 20 mM acetate-, the approximate pH and fermentation acid concentration in an infected rat intestine . Rats infected with tapeworms (12 days old) were fasted for 2 days . Starved worms were smaller but had the same percentage of body water and internal osmolality as controls . These results show that H . diminuta can regulate its body water content and that water balance is closely related to the fermentation acid concentration and pH of the bathing medium.

J Appl Bacteriol, 1991 Dec, 71(6), 524 - 30
Glucose and lactate catabolism by bacteria of the pig large intestine and sheep rumen as assessed by 13C nuclear magnetic resonance; Stevani J et al.; The fermentation of {1-13C} glucose and {3-13C}lactate by bacteria isolated from sheep rumen and pig large intestine was compared by the nuclear magnetic resonance (NMR) technique . Washed cell suspensions were incubated directly in the NMR spectrometer and spectra were recorded every 10 min after injection of the labelled substrates . The results showed large differences in the fermentation patterns between rumen and hindgut bacteria . The latter pattern indicated a greater ability for formation and fermentation of lactate than that of the rumen . Moreover, with both substrates the amount of propionate formed via the acrylate pathway was always greater with hindgut than with rumen bacteria, 50% and 20% of the total, respectively.

J Antibiot (Tokyo), 1991 Dec, 44(12), 1342 - 7
Endothelin-binding inhibitors, BE-18257A and BE-18257B . I . Taxonomy, fermentation, isolation and characterization; Kojiri K et al.; Two endothelin (ET)-binding inhibitors, BE-18257A and BE-18257B, which antagonized 125I-ET-1 binding to a porcine aortic smooth muscle membrane, were isolated from the mycelium of a strain of Streptomyces misakiensis . These binding inhibitors were extracted with methanol from mycelium and purified by HPLC.

J Antibiot (Tokyo), 1991 Dec, 44(12), 1318 - 30
Dunaimycins, a new complex of spiroketal 24-membered macrolides with immunosuppressive activity . II . Isolation and elucidation of structures; Hochlowski JE et al.; A novel complex of antifungal and immunosuppressant compounds has been isolated from the fermentation broth and mycelia of two strains of Streptomyces diastatochromogenes . The structures of eight related components were determined employing 1D and 2D homonuclear and the heteronuclear NMR spectroscopy and mass spectrometry . These structures represent the first reported spiroketal 24-membered macrolide natural products related to the common 26-membered oligomycins.

Int J Exp Pathol, 1991 Dec, 72(6), 705 - 14
Intracellular location of mycoplasmas in cultured cells demonstrated by immunocytochemistry and electron microscopy; Taylor-Robinson D et al.; Mycoplasma fermentans (strain 'incognitus') was incubated with HeLa cells for up to 96 h . After 24 h, mycoplasma organisms were demonstrated intracellularly by immunocytochemistry using mule anti-M . fermentans antiserum and gold labelling on ultrathin sections of both Lowicryl K4M and Araldite-embedded HeLa cells, the latter being treated with hydrogen peroxide . The Araldite-embedded cells were fixed with glutaraldehyde and osmium tetroxide in the presence of ruthenium red to stain the mucopolysaccharide surface components of both the procaryotic and eucaryotic cells . Intracellular localization of some M . fermentans organisms was confirmed by exclusion of ruthenium red from their membranes . Various numbers of mycoplasma organisms were seen per cell and occasionally some were within vacuoles, the membranes of which were also unstained by ruthenium red . The PG18 strain of M . fermentans and a strain of M . hominis were also detected intracellularly using similar methodology and homologous mule or rabbit antisera . The occasional presence of both apparently normal and some denser degenerate mycoplasmas in the same cell may indicate gradual degradation by phagolysosomal digestion.

J Bacteriol, 1991 Dec, 173(24), 7963 - 9
Characterization of PDC6, a third structural gene for pyruvate decarboxylase in Saccharomyces cerevisiae; Hohmann S; Pyruvate decarboxylase is the key enzyme in alcoholic fermentation in yeast . Two structural genes, PDC1 and PDC5 have been characterized . Deletion of either of these genes has little or no effect on the specific pyruvate decarboxylase activity, but enzyme activity is undetectable in mutants lacking both PDC1 and PDC5 (S . Hohmann and H . Cederberg, Eur . J . Biochem . 188:615-621, 1990) . Here I describe PDC6, a gene structurally closely related to PDC1 and PDC5 . The product of PDC6 does not seem to be required for wild-type pyruvate decarboxylase activity in glucose medium; delta pdc6 mutants have no reduced specific enzyme activity, and the PDC6 deletion did not change the phenotype or the specific enzyme activity of mutants lacking either or both of the other two structural genes . However, in cells grown in ethanol medium the PDC6 deletion caused a reduction of pyruvate decarboxylase activity . Northern (RNA) blot analysis showed that PDC6 is weakly expressed, and expression seemed to be higher during growth in ethanol medium . This behavior remained obscure since pyruvate decarboxylase catalyzes an irreversible reaction . Characterization of all combinations of PDC structural gene deletion mutants, which produce different amounts of pyruvate decarboxylase activity, showed that the enzyme is also needed for normal growth in galactose and ethanol medium and in particular for proper growth initiation of spores germinating on ethanol medium.

J Anim Sci, 1991 Dec, 69(12), 4956 - 66
Effects of dietary protein-energy interrelationships on Holstein steer performance and ruminal bacterial fermentation in continuous culture; Chester-Jones H et al.; In vivo and in vitro 3 x 2 factorial experiments were conducted concurrently to evaluate the incorporation of 0, 15, or 30% sugar beet pulp (SBP) as an energy source in diets fed to growing Holstein steers with either soybean meal (SBM) or alcohol-treated, defatted soybean flakes (ATSBF) as primary supplemental protein sources . Three groups of 42 Holstein steers each were fed six different diets from 54 kg initial BW to 320 kg in three experimental periods . There were no overall SBP level x protein source interactions (P greater than .05) . Beet pulp level tended to decrease ADG (linear, P = .05) and increase feed/gain (linear, P less than .05) and DMI (quadratic, P less than .05) . Each grower diet was used in a substrate for ruminal microbial metabolism in six dual-flow, continuous-culture fermenters . Organic matter and carbohydrate digestion were similar (P greater than .05) among diets . Increasing dietary levels of SBP caused a concomitant increase (P less than .05) in acetate and decrease (P less than .05) in butyrate and isobutyrate concentrations . Beet pulp level x protein source interactions (P less than .05) were observed for CP degradation, ammonia and nonammonia N, and dietary N flow . Crude protein degradation was higher (P less than .05) for the 0% SBP with SBM diet (81.3%) than for the 30% SBP with ATSBF diet (64.4%) . Efficiency of bacterial synthesis was similar (P greater than .05) among diets . Results indicated that SBP is an effective dietary energy source for high-energy grower diets at 15 or 30% of the DM but may cause a decrease in some performance traits . There were no nutritional benefits of using ATSBF vs SBM as the supplemental N source.

Curr Genet, 1991 Dec, 20(6), 441 - 8
Characterization of trans-acting mutations affecting Ty and Ty-mediated transcription in Saccharomyces cerevisiae; Ciriacy M et al.; By recessive mutations, we have identified five genes, TYE1-TYE5, that are required for Ty-mediated expression of ADH2 . These tye mutations not only suppress transcription of ADH2 when associated with a Ty element but are also defective in transcription of all Ty1 and Ty2 elements . Moreover, some of these mutations cause growth defects on non-fermentable carbon sources as well as sporulation defects . tye mutations also strongly suppress ADH2 expression when controlled by a polyA/T insertion mutation . Genetic analysis revealed that genes TYE3 and TYE4 are allelic to the previously identified genes SNF2 and SNF5 which code for transcription factors . These findings suggest that TYE gene products influence transcription of many genes rather than specifically Ty and Ty-mediated transcription . We have also found that null alleles of certain STE genes (ste7, ste11 and ste12), known to affect cell-type specific gene expression and expression of some Ty-adjacent genes, have a clear effect on Ty-controlled ADH2 expression depending on the carbon source . On the basis of ADH2 transcript levels in glucose-grown cells, all three ste alleles cause of five-fold reduction of ADH2 expression/transcription . In ethanol-grown cells, ste11 and ste12 mutations caused an almost complete loss of Ty-mediated ADH2 activation while ste7 has only a rather moderate effect . Surprisingly, ste11 and ste12 mutations lead to a significant increase in total Ty transcript levels . This would indicate that the STE12 protein, which is known to bind specifically to Ty1 sequences and thereby serve as an activator of a Ty-adjacent gene, can negatively modulate Ty transcription.(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemistry, 1991 Nov 26, 30(47), 11212 - 20
Differential sensitivity of the cellular compartments of Saccharomyces cerevisiae to protonophoric uncoupler under fermentative and respiratory energy supply; Beauvoit B et al.; The effect of a protonophoric uncoupler (CCCP) on the different cellular compartments was investigated in yeast grown aerobically on lactate . These cells were incubated in a resting cell medium under three conditions; in aerobiosis with lactate or glucose or in anaerobiosis with glucose as energetic substrate . For each condition, in vivo 31P NMR was used to measure pH gradients across vacuolar and plasma membrane and phosphorylated compound levels . Respiratory rate (aerobic conditions) and TPP+ uptake were measured independently . Concerning the polyphosphate metabolism, spontaneous NMR-detected polyphosphate breakdown occurred, in anaerobiosis and in the absence of CCCP . In contrast, in aerobiosis, polyphosphate hydrolysis was induced by addition of either CCCP or a vacuolar membrane ATPase-specific inhibitor, bafilomycin A1 . Moreover, polyphosphates were totally absent in a null vacuolar ATPase activity mutant . The vacuolar polyphosphate content depended on two factors: vacuolar pH value, strictly linked to the vacuolar H(+)-ATPase activity, and inorganic phosphate concentration . CCCP was more efficient in dissipating the proton electrochemical gradient across vacuolar and mitochondrial membranes than across the plasma membrane . This discrepancy can be essentially explained by a difference of stimulability of each proton pump involved . As long as the energetic state (measured by NDP + NTP content) remains high, the plasma membrane proton ATPase is able to compensate the proton leak . Moreover, this ATPase contributes only partially to the generation of delta pH . The maintenance of the delta pH across the plasma membrane, that of the energetic state, and the cellular TPP+ uptake depend on the nature of the ATP-producing process.(ABSTRACT TRUNCATED AT 250 WORDS)

Anal Biochem, 1991 Nov 15, 199(1), 125 - 31
A method for the quantitation of tryptophan in Escherichia coli fermentation broth by isocratic high-performance liquid chromatography with ultraviolet detection; Patrick JS et al.; A rapid, isocratic method for the determination of tryptophan in Escherichia coli fermentation broths by reversed-phase HPLC is described . Tryptophan can be measured in fermentations containing either chemically defined media or media with hydrolyzed protein supplements . The procedure was rugged and rereproducible (RSD = 1.7%) . The sample response was found to be linear up to 10 mcg of tryptophan/ml . Two different columns--Vydac C18 30 mm and "deactivated" SupelcoSil LC-18-DB--were compared and evaluated for use in the analysis . The deactivated columns had the residual silanols on the silica gel chemically inactivated to reduce the interaction with basic groups or analytes . The deactivated column was found to provide better peak shape (peak assymetry factor less than 1.1) and superior efficiency (plate count greater than 40000/m) and durability (greater than 3000 injections per column) than the non-deactivated column . The procedure described was found to be more selective than a fluorometric procedure.

J Mol Evol, 1991 Nov, 33(5), 418 - 25
Stomach lysozyme gene of the langur monkey: tests for convergence and positive selection; Swanson KW et al.; Genomic blotting and enzymatic amplification show that the genome of the langur monkey (like that of other primates) contains only a single gene for lysozyme c, in contrast to another group of foregut fermenters, the ruminants, which have a multigene family encoding this protein . Therefore, the langur stomach lysozyme gene has probably evolved recently (i.e., within the period of monkey evolution) from a conventional primate lysozyme . The sequences of cDNAs for the stomach lysozyme of langur and the conventional lysozymes of three other Old World monkeys were determined . Identification of the promoter for the stomach gene and comparison to the human gene, which is expressed conventionally in macrophages, show that both lysozyme genes use the same promoter . This suggests that the difference in expression patterns is due to change(s) in enhancer or silencer regulatory elements . With the cDNA sequences the hypothesis that the langur stomach lysozyme has converged in amino acid sequence upon the stomach lysozymes of ruminants is tested . Consistent with the convergence hypothesis, only those sites that specify amino acids in the mature lysozyme are shared uniquely with ruminant lysozyme genes . None of the silent sites at third positions of codons or in noncoding regions support a link between the langur and ruminants . Statistical analysis based on silent sites rules out the possibility of horizontal transfer of a stomach lysozyme gene between the langur and ruminant lineages and supports the close relationship of the langur lysozyme gene to that of other monkeys.

J Nutr, 1991 Nov, 121(11), 1769 - 75
Human calcium absorption from whole-wheat products; Weaver CM et al.; Fractional calcium absorption from wheat products and the influence of co-ingested wheat products on calcium absorption from milk were measured in a series of randomized crossover studies in healthy adult women . The wheat had been intrinsically labeled with 45Ca during growth . In the first study, fractional calcium absorption from leavened whole-wheat bread averaged 0.817 +/- 0.124 . By comparison, absorption from milk, ingested at a comparable load in the same women, averaged only 0.589 +/- 0.111 . When labeled bread was co-ingested with milk, at the same aggregate load as for bread alone, bread calcium absorption fell to 0.748 +/- 0.103 (P less than 0.05) . In a second study, calcium absorption from an extruded cereal prepared from intrinsically labeled wheat bran was compared with milk . Calcium absorption from the cereal (0.223 +/- 0.046) was significantly less than from milk (0.375 +/- 0.072) (P less than 0.001) . When the two were co-fed at the same total load, milk calcium absorption fell to 0.258 +/- 0.055 (P less than 0.001) . In a third study, the effect of phytate hydrolysis through yeast fermentation and of Maillard browning on calcium absorption was investigated using leavened bread and underbaked and overbaked cookies, each made with intrinsically labeled wheat flour . Calcium absorption from cookies was not affected by the extent of browning and averaged 0.652 +/- 0.087 . However, calcium absorption from bread in these same women averaged 0.703 +/- 0.108 . This was significantly more than from the cookies (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

J Nutr, 1991 Nov, 121(11), 1730 - 7
High propionic acid fermentations and mineral accumulation in the cecum of rats adapted to different levels of inulin; Levrat MA et al.; The digestive and metabolic effects of inulin (from chicory) were studied in rats adapted to semipurified diets containing 0, 5, 10 or 20% inulin (wt/wt) . Moderate levels of inulin (5-10%) did not significantly affect food intake or body weight gain . Dietary inulin resulted in considerably greater cecal fermentation and a significantly greater intraluminal concentration of propionate (peaking at 58.4 mmol/L) . A lower concentration of acetate (42.6 mmol/L) was observed in rats fed 20% inulin . Lactic fermentations were observed in rats fed the 10 or 20% inulin diets . The cecal pool of volatile fatty acids tended to reach a plateau in rats fed diets containing more than 10% inulin (up to 600-700 mumol), but volatile fatty acid absorption was a slightly hyperbolic function of the dietary inulin level . Butyrate absorption was proportionally lower than that of propionate . Inulin-containing diets induced an enlargement of the cecal pool of calcium, phosphate and (to a lesser extent) magnesium . There was also an enhanced absorption of these divalent cations . The cecal pool of bile acids was greater in rats fed inulin, and this oligosaccharide displayed a slight hypocholesterolemic effect, even in rats fed the 5% inulin diet . However, plasma triglycerides were depressed only in rats fed the 20% inulin diet . In conclusion, inulin seems very effective in promoting propionic fermentation and in enhancing the calcium content of the large intestine . However, high levels of inulin (greater than 10%) may affect growth in rats and lead to acidic (pH 5.65) cecal fermentation.

J Bacteriol, 1991 Nov, 173(21), 7012 - 7
Biochemical basis of mitochondrial acetaldehyde dismutation in Saccharomyces cerevisiae; Thielen J et al.; As reported previously, Saccharomyces cerevisiae cells deficient in all four known genes coding for alcohol dehydrogenases (ADH1 through ADH4) produce considerable amounts of ethanol during aerobic growth on glucose . It has been suggested that ethanol production in such adh0 cells is a corollary of acetaldehyde dismutation in mitochondria . This could be substantiated further by showing that mitochondrial ethanol formation requires functional electron transport, while the proton gradient or oxidative phosphorylation does not interfere with reduction of acetaldehyde in isolated mitochondria . This acetaldehyde-reducing activity is different from classical alcohol dehydrogenases in that it is associated with the inner mitochondrial membrane and also is unable to carry out ethanol oxidation . The putative cofactor is NADH + H+ generated by a soluble, matrix-located aldehyde dehydrogenase upon acetaldehyde oxidation to acetate . This enzyme has been purified from mitochondria of glucose-grown cells . It is clearly different from the known mitochondrial aldehyde dehydrogenase, which is absent in glucose-grown cells . Both acetaldehyde-reducing and acetaldehyde-oxidizing activities are also present in the mitochondrial fraction of fermentation-proficient (ADH+) cells . Mitochondrial acetaldehyde dismutation may have some significance in the removal of surplus acetaldehyde and in the formation of acetate in mitochondria during aerobic glucose fermentation.

Infect Immun, 1991 Nov, 59(11), 3962 - 8
Involvement of interleukin-1 (IL-1), IL-6, IL-2, and IL-4 in generation of cytolytic T cells from thymocytes stimulated by a Mycoplasma fermentans-derived product; Muhlradt PF et al.; The capacity of Mycoplasma fermentans-derived high-molecular-weight material (MDHM) to generate cytolytic T cells from mitogen-stimulated murine thymocytes was studied in detail . The role of MDHM and the involvement of monokines and lymphokines resulting from the addition of MDHM to thymocyte cultures were examined in complete and adherent cell-depleted culture systems by the addition of neutralizing monoclonal antibodies against interleukin-2 (IL-2), IL-4, and IL-6 and in reconstitution experiments with recombinant mediators . The data presented here suggest that MDHM is crucial only in the first phase of a reaction sequence beginning with the stimulation of adherent accessory cells and resulting in the synthesis of IL-1 and IL-6 . The lymphokines IL-2 and, primarily, IL-4 are required in a second step which, once these lymphokines are formed, can proceed in the absence of MDHM and accessory cells and leads to the formation of cytolytic T cells . The elucidation of the MDHM-induced reaction sequence may be of relevance in view of the hypothetical role of mycoplasmas in rheumatic disease in humans . M . fermentans is an organism capable of infecting humans and in an early report has been discussed as a causative agent for rheumatoid arthritis.

Eur J Biochem, 1991 Nov 1, 201(3), 643 - 52
Mitochondrial translational-initiation and elongation factors in Saccharomyces cerevisiae; Vambutas A et al.; C155 and E252 are respiratory-defective mutants of Saccharomyces cerevisiae, previously assigned to complementation groups G37 and G142, respectively . The following evidence suggested that both mutants were likely to have lesions in components of the mitochondrial translational machinery: C155 and E252 display a pleiotropic deficiency in cytochromes a, a3 and b; both strains are severly limited in their ability to incorporate radioactive methionine into the mitochondrial translation products and, in addition, display a tendency to loose wild-type mitochondrial DNA . This set of characteristics is commonly found in strains affected in mitochondrial protein synthesis . To identify the biochemical lesions, each mutant was transformed with a wild-type yeast genomic library and clones complemented for the respiratory defect were selected for growth on a non-fermentable substrate . Analysis of the cloned genes revealed that C155 has a mutation in a protein which has high sequence similarity to bacterial elongation factor G and that E252 has a mutation in a protein homologous to bacterial initiation factor 2 . Disruption of the chromosomal copy of each gene in a wild-type haploid yeast induced a phenotype analogous to that of the original mutants, but does not affect cell viability . These results indicate that both gene products function exclusively in mitochondrial protein synthesis . Subcloning of the IFM1 gene, coding for the mitochondrial initiation factor, indicates that the amino-terminal 423 residues of the protein are sufficient to promote peptide-chain initiation in vivo.

EMBO J, 1991 Nov, 10(11), 3373 - 7
Control of yeast GAL genes by MIG1 repressor: a transcriptional cascade in the glucose response; Nehlin JO et al.; Glucose repression is a global regulatory mechanism in yeast . We have investigated how glucose regulates the GAL genes, which are required for galactose fermentation . We found that the GAL genes are controlled by a transcriptional cascade . Thus, GAL4, which encodes an activator of the GAL genes, is repressed by MIG1, a zinc finger protein that binds to the GAL4 promoter . MIG1 has a dual role in control of the GAL genes, since MIG1 also binds to the promoter of GAL1, a gene regulated by GAL4 . A disruption of MIG1 interacts synergistically with a disruption of GAL80, a gene involved in galactose induction . This suggests that the MIG1-dependent response to glucose is amplified by down-regulation of the induction pathway.

J Protozool, 1991 Nov-Dec, 38(6), 70S - 71S
Pentamidine sensitivity and resistance in Saccharomyces cerevisiae as a model for pentamidine effects on Pneumocystis carinii; Hatfield C et al.; Pentamidine isethionate inhibits growth of Saccharomyces cerevisiae . Inhibition requires lower drug concentrations under respiratory than fermentative growth conditions . Pentamidine-resistant strains bear heritable resistance mutations . Tested mutations are dominant to wild type sensitivity . These mutations may identify cellular targets of pentamidine and potential mechanisms of fungal pentamidine resistance.

Z Naturforsch {C}, 1991 Nov-Dec, 46(11-12), 989 - 92
Omphalone, an antibiotically active benzoquinone derivative from fermentations of Lentinellus omphalodes; Stark A et al.; Omphalone, a new antibiotic, cytotoxic, and phytotoxic pigment has been isolated from fermentations of a Canadian strain of Lentinellus omphalodes . Its structure has been established as 2-(4-methylfuran-2-yl)-1,4-benzoquinone (1) by spectroscopic investigations and conversion into leuco-acetate 2.

Curr Genet, 1991 Nov, 20(5), 373 - 8
PDC6, a weakly expressed pyruvate decarboxylase gene from yeast, is activated when fused spontaneously under the control of the PDC1 promoter; Hohmann S; Three structural genes encode the pyruvate decarboxylase isoenzymes in the yeast Saccharomyces cerevisiae . PDC1 and PDC5 are active during glucose fermentation where PDC1 is expressed about six times more strongly than PDC5 . Expression of PDC6 is weak and seems to be induced in ethanol medium . Consequently, pdc1 delta pdc5 delta double mutants do not ferment glucose and do not grow on glucose medium . Spontaneous mutants, derived from such a pdc1 pdc5 strain, were isolated which could again ferment glucose . They showed pyruvate decarboxylase activity due to a duplication of PDC6 . The second copy of PDC6 was expressed under the control of the PDC1 promoter, which was still present in the pdc1 strain . However, the resulting PDC1-PDC6 fusion gene could only partially substitute for PDC1: to achieve normal growth and high pyruvate decarboxylase activity strains carrying PDC1-PDC6 required a functional PDC5 gene which is dispensable in a PDC1 wild-type background . Thus, expression of PDC5 depends on the state of the PDC1 locus: low in the PDC1 wild-type background and high in PDC1-PDC6 fusion strains and, as shown previously, in pdc1 mutants . The activation of PDC5 expression in PDC1-PDC6 strains may be due to particular properties of the PDC1-PDC6 fusion protein or simply to the weaker expression of PDC1-PDC6 in comparison to the wild-type PDC1 gene.

J Chromatogr, 1991 Nov 1, 585(2), 373 - 5
Isolation and purification of bacterial proteinases by means of autofocusing; Sitkey V et al.; Autofocusing was used for the isolation and purification of neutral and alkaline proteinases from fermentation broth, after separation of cells . The yield of proteinases achieved was 19-78%, and was inversely proportional to the degree of purification, which varied from 3.0 to 7.9 . Because of considerable losses of enzyme activity and the long duration of the process, autofocusing seems to be a non-economic technique for industrial isolation of relatively cheap enzymes.

Int J Pept Protein Res, 1991 Nov, 38(5), 401 - 8
Characterization of growth hormone releasing factor analog expression in Saccharomyces cerevisiae; Craig WS et al.; An analog of growth hormone releasing factor (GRF), {Leu27}GRF(1-40)-OH, has been expressed and secreted in Saccharomyces cerevisiae under the control of the alpha-factor gene promoter and prepro sequence . A single pair of consecutive basic residues served as a processing site between the alpha-factor sequences and the GRF sequences . {Leu27}GRF(1-40)-OH from fermentor broth containing 20-30 mg/L of immunoreactive peptides was shown to be correctly processed and to possess biological activity as measured in vitro and in vivo . Additional peptides purified from broth appear to result from proteolytic degradation of the original translation product . Analysis of the amino acid compositions and sequences of these peptides suggests that processing enzymes may be responsible for some of the degradation.

Appl Biochem Biotechnol, 1991 Nov, 31(2), 165 - 74
Comparison of different strains of the yeast Yarrowia lipolytica for citric acid production from glucose hydrol; Wojtatowicz M et al.; Four commercial strains and two mutants of the yeast species Yarrowia lipolytica were screened using batch fermentation . Strain Y . lipolytica A-101-1.14 (induced with UV irradiation) was found to be the most suitable for citric acid production from glucose hydrol (39.9% glucose and 2.1% other sugars), a byproduct of glucose production from potato starch . The specific rate of total citric and isocitric acid production was 0.138 g/g.h, the yield on consumed glucose 0.93 g/g, and the productivity achieved was as high as 1.25 g/L.h . All of the tested yeast strains were able to utilize only the glucose from the glucose hydrol medium . Thus, some residual higher oligosaccharides remained in the process effluent.

Mod Pathol, 1991 Nov, 4(6), 750 - 4
Histopathology and doxycycline treatment in a previously healthy non-AIDS patient systemically infected by Mycoplasma fermentans (incognitus strain); Lo SC et al.; The newly recognized human pathogenic mycoplasma M . fermentans (incognitus strain) causes a fatal systemic infection in experimental monkeys, infects patients with AIDS, and apparently is associated with a fatal disease in previously healthy non-AIDS patients . An apparently immunocompetent male who lacked evidence of HIV infection developed fever, malaise, progressive weight loss, and diarrhea and had extensive tissue necrosis involving liver and spleen . M . fermentans (incognitus strain) was centered at the advancing margins of these necrotizing lesions . Following the treatment of 300 mg doxycycline per day for 6 weeks, he recovered fully . He has no fever or diarrhea, and his abnormal liver function tests have returned to normal . He regained all lost strength and 14 kg of lost weight and has remained disease free for more than 1 year.

Appl Environ Microbiol, 1991 Nov, 57(11), 3232 - 6
Determination of killer yeast activity in fermenting grape juice by using a marked Saccharomyces wine yeast strain; Petering JE et al.; The Escherichia coli beta-glucuronidase gene has been used as a marker gene to monitor a killer Saccharomyces cerevisiae strain in mixed-culture ferments . The marked killer strain was cured of its M-dsRNA genome to enable direct assessment of the efficiency of killer toxin under fermentation conditions . Killer activity was clearly evident in fermenting Rhine Riesling grape juice of pH 3.1 at 18 degrees C, but the extent of killing depended on the proportion of killer to sensitive cells at the time of inoculation . Killer activity was detected only when the ratio of killer to sensitive cells exceeded 1:2 . At the highest ratio of killer to sensitive cells tested (2:1), complete elimination of sensitive cells was not achieved.

Appl Environ Microbiol, 1991 Nov, 57(11), 3114 - 20
Biochemical and serological characterization of Carnobacterium spp . isolated from farmed and natural populations of striped bass and catfish; Baya AM et al.; A comparative analysis of the phenotypic and serological properties of Carnobacterium strains associated with mortalities of cultured striped bass and channel catfish and the properties of isolates from wild brown bullhead catfish in the Chesapeake Bay area in Maryland was conducted . All of the strains were gram-positive, facultatively anaerobic, nonmotile, non-spore-forming rods occurring singly or in short chains . They did not produce cytochrome oxidase or catalase, did not reduce nitrate, failed to produce H2S, were unable to grow on acetate medium, and did not produce gas from glucose or gluconate . The temperature and salinity ranges for most of the strains were 10 to 37 degrees C and 0 to 6% NaCl, respectively . The strains all fermented mannitol and inulin and were arginine dihydrolase positive; these are typical characteristics of Carnobacterium piscicola . The carbohydrate fermentation pattern exhibited by all of the isolates with the API-50 CHL system was also very similar to that shown by C . piscicola . Acid was produced from ribose, glucose, fructose, mannose, mannitol, N-acetylglucosamine, amygdaline, arbutin, esculin, salicin, cellobiose, maltose, sucrose, trehalose, and gentiobiose . The Carnobacterium strains did not show proteolytic, lipolytic, amylolytic, or hemolytic activity . Eighteen drugs were tested; all strains proved to be resistant to chloramphenicol, gentamicin, kanamycin, streptomycin, trimethoprim, quinolones, and nitrofurans . The analysis of membrane proteins supported the phenotypic similarities, two main patterns were established, one shared by the striped bass isolates and the reference strain of C . piscicola and another shared by most of the catfish strains . However, the agglutination assays demonstrated that only one Carnobacterium strain from striped bass was serologically related to C . piscicola ATCC 35586.(ABSTRACT TRUNCATED AT 250 WORDS)

Mycopathologia, 1991 Nov, 116(2), 65 - 70
Occurrence of aflatoxins in parboiled rice in Sri Lanka; Bandara JM et al.; In Sri Lanka, rice is the main staple which is mostly processed into parboiled rice . The levels of aflatoxin B1 (AFB1) and aflatoxin G1 (AFG1) in parboiled and raw milled rice collected from major rice producing areas and rice consuming townships were estimated . In almost all the samples of parboiled rice examined, the AFB1 and AFG1 contents were significantly higher than in raw milled rice . The highest AFB1 content was 185 micrograms/kg and AFG1 content 963 micrograms/kg . These samples were collected from a major rice producing/milling district where the mean relative humidity is 78% and mean annual temperature 27 degrees C which is the highest amongst the rice growing areas in Sri Lanka . Raw rice was either free of aflatoxins or when toxins were detected, they occurred in less than 10% of the samples . The frequency of occurrence of surface fungal flora (Aspergillus/Penicillium) and aflatoxin content in market samples was closely related . Brownish or greenish moldly rice samples with fermented odour contained over 1000 micrograms/kg of AFB1.

Int J Food Microbiol, 1991 Nov, 14(2), 153 - 60
Contribution of different yeasts isolated from musts of monastrell grapes to the aroma of wine; Mateo JJ et al.; Volatile substances of wines obtained by fermentation of musts from 'Monastrell' grapes (Alicante, Spain) was studied for yeast isolated from such musts . The results of the statistical treatment performed show the importance of yeasts of low fermentative power, particularly Kloeckera apiculata, in the production of volatile substances . Saccharomyces cerevisiae var . chevalieri was found to be the most important yeast of high fermentative power.

Aust Vet J, 1991 Nov, 68(11), 361 - 3
The effects of Arctotheca calendula (capeweed) on digestive function of sheep; Pethick DW et al.; The effects of Arctotheca calendula (capeweed) on digestive function in the rumen, caecum and colon of sheep were studied . Three groups of 2-year-old Merino wethers were compared: 13 grazing capeweed-free pasture for 23 days; 8 fed 700 g of lucerne hay daily for 18 days, and 13 fed 6 kg of freshly cut capeweed (dry matter 11.3%) daily for 7 days . Capeweed did not cause diarrhoea and based on measurements of products of fermentation in the rumen, the plants were as nutritious as pasture containing grasses and clovers . The main disadvantage of capeweed in this single feeding trial was that sheep eating it lost body weight due to their inability, or lack of incentive, to consume enough dry matter.

Anticancer Res, 1991 Nov-Dec, 11(6), 2079 - 84
Cytotoxic effects of a new antitumor antibiotic, FK973, in malignant glioma; Moriuchi S et al.; A novel antitumor antibiotic, 11-acetyl-8-carbamoyloxymethyl-4-formyl-14-oxa-1, 11-diazatetracyclo {7.4.1.0(2,7).0(10,12} tetradeca-2,4,6-trien-6,9-diyl diacetate, FK973, was obtained as a fermentation product from Streptomyces sandaensis . This drug showed excellent cytotoxic effects on human glioblastoma and medulloblastoma and murine glioma (203 glioma) cells . The antitumor effects were also observed in ACNU-resistant glioma cells . The median survival time (MST) of MG models was 15 days . When they were treated with FK973, their MST was prolonged to 21 days . FK973 showed no apparent damage to murine brain cells.

J Nat Prod, 1991 Nov-Dec, 54(6), 1543 - 52
Preparation, characterization, and antiviral activity of microbial metabolites of stemodin; Hufford CD et al.; Screening studies for microbial transformation products of stemodin {2} have identified a number of microbial metabolites . Scale-up fermentation with Rhizopus arrhizus ATCC 11145 and Streptomyces sp . NRRL 5691 have resulted in the production of five metabolites that have been characterized with the use of 2D nmr and X-ray techniques . These metabolites have been identified as 18-hydroxystemodin {6}, 16,18-dihydroxystemodin {7}, 8 beta-hydroxystemodin {8}, 8 beta, 18-dihydroxystemodin {9}, and 7 beta, 8 beta-dihydroxystemodin {10} . The antiviral activity and cytotoxicity of the isolated metabolites have been evaluated.

Nutr Hosp, 1991 Nov-Dec, 6(6), 356 - 63
{Low-residue diets supplemented with fermentable fiber . Effect on experimental colonic anastomosis}; Martinez Mas E et al.; Presentation of an experimental study comparing the scarring of colic anastomoses performed in Wistar rats fed with three different types of diet: a standard laboratory diet, an enteral low-residue diet and a low-residue diet supplemented with fermentable fibre in short chain fatty acids (pectin) . Scarring in the group fed with the standard laboratory diet showed greater anastomotic complications, and the microscopic appearance was more inflamed . The administration of low-residue diets reduced the level of complications, but also reduced the concentration of collagen and the parietal rupture tension . The addition of pectin to a low-residue diet maintained the complications at a low level, and also significantly increased the pressure parameters and the collagen concentration.

J Anim Sci, 1991 Nov, 69(11), 4617 - 27
The influence of timing and the addition of urea to supplements containing DL-methionine on ruminal fermentation and cow weight change in beef cows; Wiley JS et al.; A study was conducted to determine an optimal time for supplementation of DL-methionine in relation to time of forage intake by mature British breed-type crossbred cows, and two other experiments were conducted to determine whether ruminal ammonia concentration limited changes in disappearance rates in situ and ruminal functions caused by supplements containing DL-methionine . Experiments 1 and 2 used 4 x 4 Latin square designs with four cows in each experiment . Treatments in Exp . 1 were no supplement (CON), DL-methionine at feeding (0800), DL-methionine 4 h after feeding (1200), and DL-methionine 7 h after feeding (1500) . Treatments in Exp . 2 were .5 kg of beet pulp (CON), .5 kg of beet pulp plus 16.5 g of DL-methionine (MET), .5 kg of beet pulp plus 16.5 g of DL-methionine and 55 g of urea (METU), and .4 kg of soybean (SOY) . Experiment 3 was conducted in a 326-ha pasture with treatments of no supplement (CON), .5 kg of beet pulp plus 12.5 g of DL-methionine and 30 g of urea (METU), and .4 of kg soybean meal (SOY) . In Exp . 1, in situ NDF disappearance rates of cows supplemented at 1200 and 1500 were greater (P less than .01) than those of cows supplemented at 0800 . In Exp . 2, ruminal ammonia concentration was greatest (P less than .001) for METU (5.2 mg/dl) and least for CON (1.5 mg/dl) . Disappearance rates in situ for DM differed (P less than .01) among treatments; METU was similar (P greater than .2) to SOY but faster (P less than .01) than MET . Disappearance rates of NDF were greatest (P less than .001) for METU-supplemented cows . In Exp . 3, DM and NDF disappearance rates were faster (P less than .10) for SOY than for METU . Cow BW change was positive for METU and SOY, and decrease in condition score was least (P less than .10) for METU- and SOY-treated cows . These studies indicate favorable ruminal responses to DL-methionine supplementation; however, the response depended on time of supplementation and ruminal ammonia concentration.

J Anim Sci, 1991 Nov, 69(11), 4588 - 601
Effects of a microbial inoculant and(or) sugarcane molasses on the fermentation, aerobic stability, and digestibility of bermudagrass ensiled at two moisture contents; Umana R et al.; Tifton 81 bermudagrass was harvested and ensiled either directly (D; 32.4% DM) or wilted (W; 44.1% DM) . Four treatments applied to each harvesting method were 1) control (C), or no additive; 2) dried cane molasses (M) at 5% of DM; 3) microbial inoculant (I; Pioneer 1174); and 4) a combination of Treatments 2 and 3 (MI) . Wilting reduced the rate of decline of silage pH (P = .001) and produced silages with greater lactic acid concentrations (P = .069), lower acetic acid (P = .001) and ammonia contents (P = .001), and greater in vitro OM (IVOMD; P = .001) and ADF digestibilities (IVADFD; P = .001) . These high-quality silages were less stable under aerobic conditions, as evidenced by greater average temperatures (P = .001) and greater yeast and mold counts (P = .001) . Adding M to D forage resulted in silage with lower pH (P = .001), greater concentration of lactic acid (P = .001), greater IVOMD (P = .092), and lower acetic acid (P = .009) and ammonia concentrations (P = .002) than inoculated D silage . Wilted silage treated with MI averaged lower pH (P = .025), greater lactic acid content (P = .001) and IVOMD (P = .001), and lower acetic acid (P = .001) and ammonia concentrations than silages treated with M or I alone . These results indicate that wilting improved bermudagrass silage the most, and that the addition of molasses and inoculant to wilted bermudagrass further enhanced silage quality.

Appl Microbiol Biotechnol, 1991 Nov, 36(2), 149 - 52
Production of cytotoxic proteins in Escherichia coli: a fermentation process for producing enzymatically active HIV-1 protease; Herber WK et al.; Two fermentation processes for the tryptophan-regulated expression of active HIV protease (HIV-1 prt) in Escherichia coli are described . Since overexpression of HIV-1 prt results in cell death, stringent control of product expression was necessary to attain high enzyme levels . Such control was achieved by separation of growth and production phases in a two-step process or by implementation of nutrient feed in a one-step process . When the two-stage process was used, soluble product was detectable only when induction occurred at low culture density (A550 less than 3.5) . Short induction periods of 1-2 h and rapid harvesting were necessary to recover active product . Similar results were obtained when the single-stage process was operated at 37 degrees C; however, cultivation and induction at 28 degrees C resulted in active enzyme formation following induction at increased cell density (A550 = 10).

Biochemistry, 1991 Oct 22, 30(42), 10117 - 25
Conformational stability, folding, and ligand-binding affinity of single-chain Fv immunoglobulin fragments expressed in Escherichia coli; Pantoliano MW et al.; A fluorescein-binding single-chain Fv (scFv) was chosen as a model for the study of the physicochemical parameters associated with synthetic IgG fragments . Three such scFv proteins were designed from the primary sequences of one anti-fluorescyl monoclonal antibody (Mab 4.4.20) . These were constructed with varying-length interdomain peptide linkers of between 12 and 25 residues, expressed in Escherichia coli, and the protein folding, stability, and antigen-binding characteristics were assessed . Efficient renaturation could be accomplished in vitro to yield approximately 26 mg of active scFv/L of fermentation . Scatchard analysis for fluorescein ligand binding revealed that the scFv designs come within 2-fold of the Ka = 1.99 (+/- 0.18) x 10(9) observed for the parental 4.4.20 Fab and have identical stoichiometries (n approximately 0.99) . Reversible solvent denaturation studies demonstrated that the unfolding/refolding equilibria for the scFv proteins can be fit to a simple two-state model and that two of the scFv designs were found to be slightly more stable than single IgG domains (VL and CL) when assessed in terms of the free energy of unfolding, delta Gon-u, or nearly identical to other multiple domain immunoglobulin proteins such as light chains and Fab's when relative transition midpoints, Cm, are compared . Linkers which conferred conformational flexibility beyond the minimally required length of 12 residues were found to have a stabilizing effect . By these criteria of ligand-binding function and protein stability, the scFv proteins were found to be bona fide minimal replicas of their parental IgG molecules.

Med Clin (Barc), 1991 Oct 12, 97(12), 449 - 52
{The mycoplasmas isolated from respiratory specimens}; Ferreruela RM et al.; BACKGROUND: Mycoplasma pneumoniae is the species that is considered pathogen for respiratory tract . Other species, M . hominis and U . urealyticum, have been isolated from respiratory specimens and its aetiological relation with respiratory infections is not clear . METHODS: In this study, mycoplasma from respiratory specimens have been isolated from HIV infected patients, patients suffering from chronic bronchitis and patients with respiratory infections without any underlying disease, using SP-4 media and being identified with glucose fermentation test, guinea pig blood cells adsorption, tetrazolium reduction, urea test, arginine test, and antigenic study by an immunoassay on the colonies grown on SP-4 solid medium . RESULTS: M . hominis has been the species most frequent isolated, mainly from patients without any underlying disease and from HIV infected patients, and less frequently from patients suffering from chronic bronchitis, the differences between both groups being significative . Other Mycoplasma, no identified at he species level, have been isolated although without any significative differences . In only one case U . urealyticum has been isolated . CONCLUSIONS: No M . pneumoniae isolation was obtained.

J Am Coll Nutr, 1991 Oct, 10(5), 500 - 9
The human intestinal response to enteral nutrients: a review; Jackson WD et al.; This review identifies the factors which influence mucosal integrity during enteral nutrition . These include biliary and pancreatic secretions, trophic influences of endocrine and gastrointestinal polypeptides, intestinal blood flow, and innervation . Fiber, bacterial fermentation products, purines, and glutamines are potential essential nutrients which may not be provided by parenteral nutrition . However, contrary to experience in animal models, the specific advantages of intraluminal delivery of nutrients for the maintenance of mucosal integrity and structure remain unproven in the human . Current evidence in the human suggests that changes in small bowel structure and function when enteral nutrients are excluded are minor and rapidly reversible as long as general nutritional status is maintained.

J Antibiot (Tokyo), 1991 Oct, 44(10), 1096 - 100
Microbial O-carbamylation of novobiocin; Kuo MS et al.; Novobiocin was inactivated by Streptomyces niveus US 2094 in fermentation . The inactivation product was isolated and characterized by NMR and MS as 2"-O-carbamylnovobiocin . The MICs of novobiocin and 2"-O-carbamylnovobiocin were determined for S . niveus strains.

J Antibiot (Tokyo), 1991 Oct, 44(10), 1054 - 60
New antitumor substances, BE-12406A and BE-12406B, produced by a streptomycete . I . Taxonomy, fermentation, isolation, physico-chemical and biological properties; Kojiri K et al.; New antitumor substances, designated BE-12406A and BE-12406B, were isolated from the culture broth of a streptomycete, strain BA 12406 . The active principles were extracted from mycelium by methanol and successively purified by silica gel column chromatography and preparative TLC . BE-12406A and BE-12406B inhibited the growth of vincristine-resistant or doxorubicin-resistant P388 murine leukemia cell lines as well as their parent sensitive cell line . In in vivo experiments, BE-12406A inhibited the growth of S-180 murine ascites tumor.

J Antibiot (Tokyo), 1991 Oct, 44(10), 1045 - 53
Duocarmycins, new antitumor antibiotics produced by Streptomyces; producing organisms and improved production; Ichimura M et al.; Six duocarmycins have been discovered during our search for new antitumor antibiotics and they showed extremely potent cytotoxic activity with IC50 values of 10(-12) M-10(-9) M on HeLa S3 cell . Three different producing strains isolated from soils were taxonomically assigned as Streptomyces . Duocarmycin A was unstable in culture broth, so improved culture conditions were designed to produce a high titer of duocarmycins B1, B2, C1 and C2 which are halogenated seco-compounds of duocarmycin A . Duocarmycin SA, one of the most potent cytotoxic agents yet discovered, was shown to be more stable in culture media than duocarmycin A, despite the structural similarity on their spirocyclopropylhexadienone moiety . In contrast to the duocarmycin A fermentation, no halogenated seco-compounds of duocarmycin SA were detected in culture broth supplemented with Br- or Cl- . All duocarmycins could be produced using one producing strain with improved media and culture conditions.

Am Ind Hyg Assoc J, 1991 Oct, 52(10), 433 - 7
High-performance liquid chromatographic method for the determination of occupational exposure to the pesticide abamectin; Jongen MJ et al.; As part of a survey of occupational exposure to pesticides in greenhouses for growing ornamentals, analytical methods were developed and validated for the measurement of exposure of workers to the pesticide abamectin . Abamectin consists of a mixture of avermectin-B1a and avermectin-B1b, which are members of a class of fermentation products of the soil microorganism Streptomyces Avermitilis . Because of the high molecular weight of the avermectins (greater than 800 daltons), high-performance liquid chromatography (HPLC) was the analytical method of choice . Previously described HPLC methods that used fluorescence detection were adapted and validated for the determination of dermal exposure by the analysis of cotton gloves and foliar dislodgeable residue . IOM samplers (developed at the Institute of Occupational Medicine, Edinburgh, U.K.) for collecting the inspirable fraction of dust or aerosols were tested for the determination of airborne abamectin concentrations in greenhouses . An analytical procedure considerably simpler than published methods appeared suitable for the determination of abamectin residues on cotton gloves and on greenhouse foliage . Analytical recovery from cotton gloves, solutions of foliar dislodgeable residues, and air-sampling filters was essentially complete . However, air concentrations of abamectin could not be reliably measured by using the IOM sampling device because of breakdown during sampling . Between-day coefficients of variation for solutions of dislodgeable residue and cotton glove extracts were between 3% and 6% for abamectin concentrations between 5 and 140 micrograms/L.

Gastroenterology, 1991 Oct, 101(4), 935 - 42
Action of beer and its ingredients on gastric acid secretion and release of gastrin in humans; Singer MV et al.; The intragastric action of beer and its known ingredients before and after fermentation on gastric acid secretion and release of gastrin was studied in healthy humans . None of 11 tested ingredients of fermented beer (2 x 500 mL, pH 5.5, given either alone or in combination) or hop extract had any significant effect . Finished beer (6 weeks old) and new beer were potent stimuli of acid output, causing 93% and 76% of the incremental maximal acid output in response to pentagastrin (6 micrograms/kg SC), respectively . Before the addition of yeast, preproducts of beer were considerably less potent . Thus, first and finished wort caused only a minor acid response which was 48% and 46% of maximal acid output . Foreign fermentation in first and finished wort is presumably the reason for the stimulatory action because glucose solutions in concentrations (11.5% wt/vol) seen in wort did not stimulate acid secretion . However, glucose solutions to which yeast was added, resulting in fermentation, were as potent stimuli of acid secretion as beer . Lyophilization of beer at pH 11.0 and dialysis (cutoff mol wt, 1000) removed the stimulatory substances . The plasma gastrin responses paralleled the gastric acid response to the different stimulants . It was concluded that (a) the addition of yeast to finished wort and the following alcoholic fermentation are the essential steps for the stimulatory action of beer on gastric acid secretion and release of gastrin; (b) carbohydrate metabolites with a molecular weight of less than 1000 are the acid-stimulatory agents in fermented beer; and (c) gastrin is the mediator of the stimulation of acid secretion because all substances that had a potent acid-stimulatory action also were potent stimuli of gastrin release.

J Dairy Sci, 1991 Oct, 74(10), 3492 - 5
Niacin absorption from the rumen; Erickson PS et al.; Absorption of niacin from the rumen was tested in vivo using a buffer solution that contained either nicotinic acid or nicotinamide . The experimental design was a 3 X 3 Latin square with three midlactation, ruminally cannulated Holstein cows . Orthogonal comparisons were control versus niacin and nicotinic acid versus nicotinamide . Nicotinamide was more rapidly absorbed from the rumen than nicotinic acid; this may have been caused by differences in the dissociation constants of the compounds . The effects that differential absorption may have on ruminal fermentation and animal metabolism require further study.

Antonie Van Leeuwenhoek, 1991 Oct-Nov, 60(3-4), 275 - 92
Application of a metabolic balancing technique to the analysis of microbial fermentation data; de Hollander JA; A general method for the development of fermentation models, based on elemental and metabolic balances, is illustrated with three examples from the literature . Physiological parameters such as the (maximal) yield on ATP, the energetic maintenance coefficient, the P/O ratio and others are estimated by fitting model equations to experimental data . Further, phenomenological relations concerning kinetics of product formation and limiting enzyme activities are assessed . The results are compared with the conclusions of the original articles, and differences due to the application of improved models are discussed.

Antonie Van Leeuwenhoek, 1991 Oct-Nov, 60(3-4), 257 - 73
The use of stoichiometric relations for the description and analysis of microbial cultures; de Hollander JA; A general method is described, which enables the derivation of predictive fermentation equations for any microbiological process . The method combines the well-known achievements of the elemental balance approach with microscopic, metabolic balances and biochemical restrictions, using the key intermediates concept . Special attention is paid to the distinction between independent and dependent flow variables of a system . The method is fully illustrated for the very simple example of heterotrophic growth on a single substrate without product formation . Other examples include growth on mixed substrates and the description of catabolic and anabolic product formation.

J Protein Chem, 1991 Oct, 10(5), 517 - 26
Thrombin and H64A subtilisin cleavage of fusion proteins for preparation of human recombinant parathyroid hormone; Forsberg G et al.; Human parathyroid hormone, hPTH, an 84 amino acid polypeptide, was produced intracellularly in Escherichia coli as a fusion protein, linked to the C-terminus of a 15 kD IgG-binding protein . Approximately 100 mg fusion protein was obtained per liter fermentation medium . To test the efficiency of two alternative enzymatic cleavage methods, two fusion proteins differing only in the linker region were constructed . Cleavage of a Phe-Phe-Pro-Arg linker was obtained with bovine thrombin and cleavage of a Phe-Ala-His-Tyr linker with recombinant H64A subtilisin . Both enzymes yielded the correct N-terminus and cleaved their respective linkers quantitatively, although additional internal cleavage sites in hPTH were detected and characterized . The linker cleavage conditions were optimized and hPTH was purified to homogeneity . Thrombin cleavage resulted in a final yield of 5 mg hPTH/L, while H64A subtilisin cleavage was more specific and gave 8 mg/L . The purified recombinant product was identical to native hPTH and exhibited full biological activity in an adenylate cyclase assay.

Appl Biochem Biotechnol, 1991 Oct, 31(1), 83 - 96
The promotion of molasse alcoholic fermentation using Saccharomyces cerevisiae in the presence of gamma-alumina; Iconomou L et al.; Using gamma-alumina pellets, more than threefold increase of the ethanol productivity in the fermentation molasse has been obtained in the present work . Also, molasse fermentation in the presence of gamma-alumina gave 78.4 g/L ethanol, ethanol yield factor 0.44 g/g, and conversion 89.4% at initial sugar concentration (ISC) 179.5 g/L, compared to 53.9 g/L, 0.30 g/g and 62.7% in its absence, respectively . Furthermore, it was found that gamma-alumina reduces the activation energy Ea of fermentation . This inorganic material does not promote the fermentation of raisin extract.

Arch Tierernahr, 1991 Oct, 41(7-8), 725 - 36
Sulphur availability and microbial fermentation in the fauna-free rumen; Hegarty RS et al.; The concentration of H2S and rate of feed digestion, VFA and methane production in the rumen were measured in sulphur deficient (-S) and S supplemented (+S) sheep while fauna-free (-P) and after refaunation (+P) . The concentration of rumen H2S was increased by S supplementation but was not affected by the presence of protozoa . When fauna-free, -S sheep had reduced rates of feed digestion (30 v 48%/d), acetate synthesis (35 v 115 g/d) and methane synthesis (0.4 v 7.4 g C/d) compared to +S sheep and up to 36% (v/v) of total rumen gas was H2 . When these sheep were given a single dose of 8.8 g Na2SO4, the proportion of methane increased and the proportion of H2 in rumen gas decreased . After refaunation of sheep, their rates of feed digestion, VFA production and methane production were higher and were not affected by the level of S . From this differential response to S deficiency by -P and +P sheep, it is concluded rumen protozoa increase the availability of S to other rumen microbes . This is probably because they degrade protein through to peptides and amino acids.

FEMS Microbiol Lett, 1991 Oct 1, 67(2), 153 - 7
Expression of nrdA and nrdB genes of Escherichia coli is decreased under anaerobiosis; Casado C et al.; By using plasmid nrdA-lacZ, nrdAB-lacZ, and nrdB-lacZ gene fusions, the expression of nrdA and nrdB genes of Escherichia coli under anaerobiosis has been studied . The results obtained show that cells of E . coli growing under either fermentative or nitrate respiring conditions present a lower basal level of both nrdA and nrdB genes transcription from the nrdPA promoter . On the other hand, transcription of the nrdB gene from the internal nrdPB promoter was not affected by the absence of oxygen . Moreover, the DNA damage-mediated inducing factor of these nrd genes was the same in both aerobic and anaerobic cultures.

J Dairy Sci, 1991 Oct, 74(10), 3630 - 44
Balancing carbohydrates and proteins for optimum rumen microbial yield; Hoover WH et al.; Establishing conditions under which rumen fermentation will be optimized requires an understanding of the nutrient requirements of the mixed microbial population . The major nutrients required by rumen microbes are carbohydrates and proteins, but the most suitable sources and quantities needed to support maximum growth have not been determined . Digestion of proteins results in the production of peptides, which can accumulate in the rumen . Peptides are further hydrolyzed to amino acids, some of which are deaminated, producing ammonia . Although peptides, amino acids, and ammonia all may individually serve as sources of N for various microbes, the total population achieves the highest growth rate on mixtures of all three sources . In a somewhat analogous manner, carbohydrates are digested by exoenzymes to oligosaccharides that are available for crossfeeding by the mixed microbial population . Based on data from both in vitro and in vivo studies, there is general agreement that rate of digestion of carbohydrates is the major factor controlling the energy available for microbial growth; in addition, rate of digestion of total carbohydrate is directly related to proportion of starches, pectins, and sugars . Proteins affect both total fermentation and production of microbial DM per unit of carbohydrate fermented . It appears that the quantity of ruminally available protein needed to optimize microbial growth may, under some conditions, be as high as 14 to 15% of diet DM.

J Dairy Sci, 1991 Oct, 74(10), 3518 - 23
Effect of sometribove on rumen fermentation, rate of passage, digestibility, and milk production responses in dairy cows; Winsryg MD et al.; Six ruminally and duodenally fistulated Holstein cows 60 d postpartum were assigned randomly to each of two treatments in a single reversal design . Treatments consisted of placebo or 25 mg of sometribove (bST) injected daily . Treatments were initiated at 60 d +/- 7 postpartum and maintained for 6 wk with a 3-wk adjustment between treatment periods . All cows received a TMR consisting of 16% CP and 1.67 Mcal of NE I/kg of DM . Influence of bST on rumen fermentation characteristics, digesta rate of passage, apparent nutrient digestibility, and milk production was evaluated . Milk yield of treated animals was 4.0 kg/d higher than controls . The 3.5% FCM and milk production efficiency (3.5% FCM/DMI) were significantly higher in treated animals than in controls (29.0 vs . 25.4 kg/d and 1.38 vs . 1.21 kg/kg, respectively) . Percentage of rumen cellulolytic bacteria (of total viable bacteria) was not significantly different for bST-treated animals (6.4 vs . 3.4%) . Total number of rumen protozoa tended to be higher (7.25 vs . 6.55 x 10(3)/ml) in bST-treated animals . Ruminal percentages of CP, NH3 N, alpha-amino N, VFA, and pH were unaffected by treatment . Sometribove treatment did not significantly affect liquid dilution or solids turnover rates . Percentages of CP, alpha-amino N, and NH3 N content in duodenal samples were unaffected by treatment . Total tract apparent digestibility of nutrients and mean daily DMI were unaffected by treatment.

Int J Syst Bacteriol, 1991 Oct, 41(4), 473 - 8
Identification of a plant-derived mollicute as a strain of an avian pathogen, Mycoplasma iowae, and its implications for mollicute taxonomy; Grau O et al.; Strain PPAV, a filamentous but nonhelical mollicute, was isolated from aborted apple seeds in France in late 1979 . This organism grew well in SP-4 broth, fermented glucose, and required sterol for growth, and most of its properties suggested that it belonged to the genus Mycoplasma . However, it was serologically distinct; in addition, unlike other Mycoplasma species, genome measurements consistently yielded values of about 1,000 MDa (ca . 1,500 kbp), and the organism had a growth temperature optimum of 43 degrees C . A comparison of strain PPAV 16S rRNA sequences with those of other mollicutes revealed a high degree of sequence similarity to a strain of Mycoplasma iowae, which is commonly encountered in poultry . This relationship was confirmed by performing a restriction endonuclease pattern analysis and DNA-DNA hybridization tests . The genome size of type strain 695 of M . iowae was determined to be about 1,000 MDa (1,500 kbp) by renaturation kinetics, a value which is much higher than any other value known in the genus . Additional measurements by pulsed-field gel electrophoresis yielded values of 1,300 kbp for both strain PPAV and M . iowae . Subsequent phenotypic comparisons supported this relationship . Serologic tests with strain PPAV and other strains of M . iowae confirmed the findings of other investigators that this species is serologically heterogeneous . The high optimum temperature for growth of strain PPAV was also shared by a number of M . iowae isolates . Genome size is an inappropriate character for taxonomic assignment to the family Mycoplasmataceae because strain PPAV and other established species in this family are now known to have genomes ranging in size from 1,000 to 1,400 kbp.

J Dairy Sci, 1991 Oct, 74(10), 3505 - 17
Effect of bovine somatotropin and protein on rumen fermentation and forestomach and whole tract digestion in dairy cows; Robinson PH et al.; Four lactating Holstein cows with permanent ruminal and duodenal cannulas were allocated to one of two TMR with either 17.1 or 23.6% CP at 5 to 9 d postpartum . Cows also were assigned to either bST (20.6 mg/d) or excipient (control) treatment at that time for the 84-d experiment but were switched to different protein levels every 21 d in four periods . Intake of DM and forestomach and whole tract digestion of DM were unaffected by treatments . Forestomach and whole tract apparent digestion of N was higher for cows fed the high protein diet . Forestomach NDF and ADF digestion was higher for cows fed the high protein diet but was significant for control cows only . Rumen pH, ammonia N, and isovalerate were higher for cows fed the high protein diet . Rumen ammonia N and acetate were lower for bST-treated cows . Rumen pool sizes of total ingesta, DM, NDF, and bacterial OM were not affected by either treatment . However, the total pool size of rumen NAN and nonbacterial NAN was larger for cows fed the high protein diet . Duodenal flow of AA was higher for cows fed the high protein diet . However, duodenal protein AA profiles were similar among treatments except for lysine, which was higher, and methionine and alanine, which tended to be lower, for cows fed the high protein diet . There were few bST x protein or bST x duration of treatment interactions . Results support the concept that bST-treated cows have digestive metabolism similar to untreated cows of similar actual production.

J Ind Microbiol, 1991 Oct, 8(3), 171 - 8
Effect of cultural conditions on production of eicosapentaenoic acid by Pythium irregulare; Stinson EE et al.; The effect of culture conditions upon lipid content and fatty acid composition of mycelia of Pythium irregulare was investigated with particular attention to increasing the yield of 5,8,11,14,17-eicosapentaenoic acid (20:5; omega-3)(EPA) . All experiments were done by shake flask culture using a yeast extract + malt extract medium . The maximum growth rate was obtained at 25 degrees C, but maximum EPA production was obtained at 12 degrees C . The highest EPA production was 76.5 micrograms EPA/ml 13 days fermentation at 12 degrees C . Addition of glucose during fermentation increased the yield considerably . The highest yield was 112 micrograms/ml, obtained at 13 days fermentation with spiking on day 11 . Fermentation time could be shortened by initial incubation at 25 degrees C for 2 days, followed by incubation at 12 degrees C for 6 days . The culture also produced arachidonic acid and other omega-6 polyunsaturated fatty acids . EPA production was also obtained with lactose or sweet whey permeate, a by-product of cheese manufacture that contains lactose as the main carbohydrate.

J Ind Microbiol, 1991 Oct, 8(3), 157 - 64
Bioconversion of the sodium salt of simvastatin (MK-733) to 6-desmethyl-6-alpha-hydroxymethyl simvastatin; Marcin C et al.; An actinomycete (MA 6474, ATCC 53828) isolated from a soil sample (Mutare, Zimbabwe) was found to biotransform the sodium salt of Simvastatin (MK-733) to 6-alpha-hydroxymethyl MK-733, 6-beta-hydroxymethyl MK-733, and 6-ring-hydroxy MK-733 . The bioconversion efficiency to the desired compound, 6-alpha-hydroxymethyl MK-733, was enhanced by optimizing the physico-chemical parameters of the process . In shake flask cultures, addition of magnesium (0.125 mg/l Mg SO4.7H2O) to the medium resulted in a five-fold increase in the rate of bioconversion to the alpha diastereomer . The ratio of bioconversion products (6-alpha-hydroxymethyl,6-beta-hydroxymethyl, and 6-ring-hydroxy MK-733) was regulated by pH . Process improvements and scale up in 23-1 fermentors, which consisted of a controlled addition of substrate (MK-733), resulted in a 2-fold increase in alpha diastereomer production (42 vs . 79 U/ml) and a 23-fold rate increase in the formation of alpha-diastereomer . A high diastereomeric ratio (alpha: beta = 9:1) facilitated downstream processing.

J Ind Microbiol, 1991 Oct, 8(3), 147 - 56
Fermentation study for the production of hepatitis B virus pre-S2 antigen by the methylotrophic yeast Hansenula polymorpha; de Roubin MR et al.; Various physico-chemical parameters have been studied in order to improve the production of hepatitis B virus pre-S2 antigen (middle surface antigen) by the methylotrophic yeast Hansenula polymorpha . Antigen production was done in two steps: first, production of cells on glycerol (Phase 1), followed by induction of antigen expression with methanol (Phase 2) . Dense cultures of H . polymorpha, equivalent to 35-40 g/l (dry weight), were readily obtained in small fermenters using minimal medium containing glycerol as carbon source . Antigen expression in this minimal medium, after induction with methanol, was however, low and never exceeded 1.6 mg/l of culture . Antigen production was greatly enhanced by adding complex organic nitrogen sources along with methanol at induction time; yeast extract was the best of all the sources tested . In shake flasks, antigen production was proportional to yeast extract concentration up to 7% (w/v) yeast extract, it became clear the the nutritional conditions for good antigen expression were different from those for good biomass production . The effects of yeast extract were reproduced in small fermenters: antigen levels reached 8-9 mg/l in medium containing 6% (w/v) yeast extract during induction with methanol . The mechanisms of yeast extract's effects are still unknown but are probably nutritional . The recombinant H . polymorpha strain produced both periplasmic and intracellular antigen . The periplasmic antigen was shown to be present as 20-22-nm particles and was therefore immunogenic . Immunoblotting indicated that part of the pre-S2 antigen was present as a 24-kDa degradation product . These studies have led to a 140-fold increase in volumetric productivity of antigen and to a 4.6-fold increase in specific production.

Appl Microbiol Biotechnol, 1991 Oct, 36(1), 14 - 20
Optimization of growth conditions for the production of proteolytically-sensitive proteins in the periplasmic space of Escherichia coli; Baneyx F et al.; The expression of many secreted recombinant proteins in Gram-negative bacteria is limited by degradation in the periplasmic space . We have previously shown that the production of protein A-beta-lactamase, a secreted fusion protein highly sensitive to proteolysis in Escherichia coli, can be increased in mutant strains deficient in up to three cell-envelope-associated proteolytic activities . In this work we investigated the effect of fermentation conditions on suppressing any residual proteolytic activity in various protease-deficient strains . Optimal production of the fusion protein was observed in cells grown under mildly acidic conditions (5.5 less than or equal to pH less than or equal to 6.0) and a low temperatures . These conditions were shown to specifically decrease the rate of proteolysis . In addition, a further increase in production was observed in cultures supplemented with 0.5 to 0.75 mM zinc chloride . This may relate to the inhibition of a cell envelope protease by Zn2+ ions.

FEBS Lett, 1991 Sep 9, 289(2), 159 - 62
ADP/ATP translocator is essential only for anaerobic growth of yeast Saccharomyces cerevisiae; Drgon T et al.; All three genes (AAC1, AAC2 and AAC3) encoding the mitochondrial ADP/ATP translocator, were inactivated in a haploid yeast strain by a gene disruption technique . The triple mutant was still able to grow on fermentable carbon sources but only in the presence of oxygen . Under aerobic conditions neither translocator-protein nor carrier-mediated transport was detected in all mutants in which the AAC2 gene was disrupted . It was further shown that a functional AAC genes product is essential only for anaerobic growth of Saccharomyces cerevisiae but not for growth under derepressed conditions . Under anaerobic conditions a non-detectable amount of AAC3 gene product is sufficient to ensure the cell growth and multiplication.

J Mol Biol, 1991 Sep 5, 221(1), 97 - 105
Temperature-sensitive variants of Saccharomyces cerevisiae iso-1-cytochrome c produced by random mutagenesis of codons 43 to 54; Wang XH et al.; In vitro random mutagenesis within the CYC1 gene from the yeast Saccharomyces cerevisiae was used to produce a library of mutants encompassing codons 43 to 54 of iso-1-cytochrome c . This region consists of an evolutionarily conserved structure within an evolutionarily diverse sequence . The library, on a low-copy-number yeast shuttle phagemid, was introduced into a yeast strain lacking cytochrome c . The ability of transformants harboring a functional cytochrome c to grow on the non-fermentable carbon source glycerol at 30 degrees C and 37 degrees C was used to determine the phenotype of nearly 1000 transformants . Approximately 90% of the missense mutants present in the library give rise to the wild-type phenotype, 7% result in the temperature-sensitive (Cycts) phenotype, and 3% give rise to the non-functional (Cyc-) phenotype . Phagemids from 20 Cycts and 30 Cyc- transformants were subjected to DNA sequence analysis . All the mutations occur within the targeted region . One-third of the mutants from Cyc- transformants and all the mutants from Cycts transformants are missense mutants . The remaining mutants from Cyc- transformants are nonsense or frame-shift mutants . Missense mutations within the codons for Gly45, Tyr46, Thr49, Asn52 or Ile53 alone are sufficient to produce temperature-sensitive behavior both in vivo and in the variant proteins . The deduced amino acid substitutions correlate remarkably well with side-chain dynamics, secondary structure and tertiary structure of the wild-type protein.

Blutalkohol, 1991 Sep, 28(5), 312 - 20
{Alcoholic fermentation in "Schwabischen Most": ethanol and alcoholic congener alcohols}; Graw M et al.; The concentrations of ethanol and congener alcohols in "Schwabischer Most" were determined (1) at various stages throughout the fermentation process in two different types of "Most", and (2) after completed fermentation in eleven different types . The fermentation process was finished after about five weeks with a final ethanol concentration of 35-54 g/l . According to the congener alcohols the different specimens of "Most" could be classified as beverages like wine . However, the concentrations were found to vary so widely that the analysis of the beverage in question is to be recommended whenever an expert opinion is given . Our studies suggest that the alcohol concentrations do not change significantly, when the fermentation process has been finished.

J Anim Sci, 1991 Sep, 69(9), 3826 - 37
Supplemental fat in high-energy rations for lactating cows: effects on intake, digestion, milk yield, and composition; Coppock CE et al.; Supplemental fats (SF) have special value in the diets of dairy cows with superior productive ability, because the high energy density of SF allows greater energy consumption and direct transfer of the fatty acids (FA) of the SF to milk fat; this increases metabolic efficiency . Some SF, especially oils with a high degree of unsaturation, disturb ruminal fermentation, decrease fiber digestibility, and lower milk fat test; however, oilseeds (e.g., whole cottonseed) can be fed without observable ruminal inhibition, probably because of a slow release of the oil into ruminal contents . A number of commercial fat supplements are available that have little effect on ruminal fermentation and are highly digestible postruminally . A product of the calcium salts of palm oil fatty acids was shown to have a NE for lactation of more than three times that of corn . As the emphasis in milk pricing formula changes from milk fat to milk protein, there is greater concern regarding the propensity of fat supplements to decrease milk protein (casein) percentage . In two studies, a supplement of ruminally protected lysine and methionine largely prevented the reduction in casein percentage that occurred with feeding SF, indicating that the amino acid profile of undegraded dietary protein is important with regard to preventing the lower casein percentage . Combining fat supplements that are slowly released in the rumen with those that are inert in the rumen will allow maximal use of SF.

J Antibiot (Tokyo), 1991 Sep, 44(9), 949 - 55
Poststatin, a new inhibitor of prolyl endopeptidase, produced by Streptomyces viridochromogenes MH534-30F3 . I . Taxonomy, production, isolation, physico-chemical properties and biological activities; Aoyagi T et al.; Poststatin, a new inhibitor of prolyl endopeptidase (PEP) was discovered in the fermentation broth of Streptomyces viridochromogenes MH534-30F3 . It was purified by Diaion HP-20, Sephadex LH-20 and YMC-gel (ODS-A) column chromatography and then isolated as a colorless powder . Poststatin has the molecular formula C26H47N5O7 . The IC50 value of poststatin against the PEP of partially purified porcine kidney was 0.03 microgram/ml . It has low acute toxicity . No deaths occured after iv injection of 250 mg/kg of this agent to mice.

Infect Immun, 1991 Sep, 59(9), 3319 - 22
Protein and antigen heterogeneity among strains of Mycoplasma fermentans; Stadtlander CT et al.; The proteins and antigens of three strains of Mycoplasma fermentans were compared with those of a mycoplasma, designated "Mycoplasma incognitus," recently identified in tissues of AIDS patients . Previous studies have shown that "M . incognitus" is most likely not a new species but rather a strain of M . fermentans . In the present study, one- and two-dimensional electrophoretic analysis demonstrated the expected similarity between these mycoplasmas, but it also demonstrated several distinct protein differences . Nine proteins were identified as strain variable by two-dimensional gel electrophoresis . Also, immunoblot analysis using rabbit antiserum against the type strain of M . fermentans (strain PG 18) documented the occurrence of size heterogeneity in at least one and possibly two other antigens.

J Dairy Sci, 1991 Sep, 74(9), 3117 - 27
Effects of somatotropin and duodenal infusion of amino acids on nutrient passage to duodenum and performance of dairy cows; Lynch GL et al.; Four multiparous Holstein cows were used in a 4 x 4 Latin square to investigate the effects of bST and postruminal infusion of lysine and methionine on ruminal fermentation, flow of nutrients to the small intestine, and animal performance . The treatments were 1) control; 2) control plus 24 g of lysine and 8 g of methionine/d; 3) control plus 25 mg of bST/d; and 4) control plus 25 mg of bST/d plus 24 g of lysine and 8 g of methionine/d . Intakes of DM, OM, CP, starch, NDF, and ADF were similar among treatments . Ruminal characteristics, flow of nutrients to the small intestine, and total tract apparent digestibilities of nutrients were not affected by injection of bST or postruminal infusion of lysine and methionine in this short-term experiment . Milk production, 4% FCM, milk fat percentage and yield, and production of milk CP were increased by administering bST . Postruminal infusion of lysine and methionine did not affect milk production or composition.

Prikl Biokhim Mikrobiol, 1991 Sep-Oct, 27(5), 762 - 71
{Fermentation micromethod for the quantitative determination of thiamine diphosphate in biological fluids}; Chernikevich IP et al.; An enzymatic micromethod is proposed for quantification of thiamine biphosphate (TBP) at concentrations from 0.5 ng in 0.1-0.2 ml samples of blood or other biological liquids . The dynamics of TBP degradation in blood was studied depending on the time and conditions of storage . A high efficient complex of alcohol dehydrogenase and apopyruvate decarboxylase was isolated from baker's yeasts that can be successfully used for quantitative detection of TBP . The complex was stabilized for further application to biochemical kits for diagnosis of B1-deficiency.

Mol Microbiol, 1991 Sep, 5(9), 2079 - 84
Control of maltase synthesis in yeast; Needleman R; Maltose fermentation in Saccharomyces species requires the presence of at least one of five unlinked MAL loci: MAL1, MAL2, MAL3, MAL4 and MAL6 . Each MAL locus is complex consisting of at least three genes: a trans-acting activator, a maltose permease, and maltase . All the MAL loci show homology to each other both at the sequence level as determined by Southern transfer analysis and at the functional level as determined by complementation . We describe the organization of the MAL loci in yeast and the basic features of their regulation . The analysis of MAL has contributed to our understanding of the evolution of multigenic families, the global integration of carbohydrate metabolism, and gene regulation.

Microbiologia, 1991 Sep, 7(2), 120 - 5
{ Taxonomic study of the yeast flora of musts and wines from "Madrid wines".}; Hidalgo P et al.; The natural yeast flora of musts and wines elaborated in wineries of the three Madrid viticultural areas, has been taxonomically analyzed . Two hundred and seventy yeast strains belonging to eighteen species, have been isolated, and Sacch . cerevisiae strains are the most frequent . The chemical characterization of samples with enological parameters defines the yeast fermentative ecosystem.

Mycopathologia, 1991 Sep, 115(3), 163 - 8
Effect of the incubation conditions on the production of patulin by Penicillium griseofulvum isolated from wheat; Jimenez M et al.; Sixty-four wheat samples from Spanish flour factories were screened for patulin and patulin-producing moulds . None of them was found to contain any patulin, whereas samples experimentally contaminated with this toxin proved it to be highly unstable . On the other hand, Penicillium griseofulvum was the only in vitro patulin-producing species found (19 samples) . Mould growth in the samples was investigated by using yeast-sucrose medium (YES) and high-performance liquid chromatography (HPLC) to measure the amounts of toxin produced during 40 day's incubation at 20 and 28 degrees C . The highest yield rate of patulin was obtained between the 20th and 30th day of incubation; such a rate, however, was very low throughout the vigorous growth phase, during the first 20 days of incubation . The more appropriate temperature for incubation and patulin production was 28 degrees C . We also investigated the influence of other incubation conditions in the yield and found stationary dark cultures to be more efficient that shaken or fermentation cultures in YES medium . The best patulin yield achieved was 11.9 mg in the culture broth and 6.3 mg in the mycelium from 100 ml of medium.

Br J Nutr, 1991 Sep, 66(2), 313 - 29
Large bowel fermentation in rats eating processed potatoes; Mathers JC et al.; Four diets were prepared in which cooked potatoes provided approximately 0.8 of the dry matter (DM) and all the polysaccharides . The potatoes were either boiled conventionally (unprocessed) or prepared by rehydrating a commercial 'instant' potato product with boiling water . The diets were fed to rats (six per diet) immediately after preparation or after storage at 4 degrees for 48 h and observations made on site and extent of digestion and large bowel (LB) fermentation . All diets were equally well digested (overall means 0.95 and 0.96 for DM and organic matter (OM) respectively) with a significant proportion of this digestion occurring in the LB . More OM flowed to the LB with the 'instant' (0.18 of intake) than with the unprocessed potato diets (0.13 of intake) and was associated with markedly different fermentation patterns . When compared with rats fed on the unprocessed potato diets, those given 'instant' potatoes had smaller caecums with much shorter transit times, lower caecal pH, higher total volatile fatty acid (VFA) concentrations and a greater molar proportion of butyrate in these VFA . Storage of the diets for 48 h at 4 degrees had relatively smaller effects on these variables . Possible mechanisms for the observed effects and implications for tissue metabolism and health are discussed . In addition, a simple and apparently novel method for quantifying coprophagy is proposed.

J Anim Sci, 1991 Sep, 69(9), 3789 - 97
Effects of cottonseed meal supplementation time on ruminal fermentation and forage intake by Holstein steers fed fescue hay; Judkins MB et al.; Four ruminally cannulated Holstein steers (average BW 303 kg) were used in a 4 x 4 Latin square design digestion trial to study the influence of daily cottonseed meal (CSM; 1.6 g of CP/kg of BW) supplementation time on forage intake and ruminal fluid kinetics and fermentation . Steers were housed individually in tie stalls and were fed chopped fescue hay on an ad libitum basis at 0600 and 1400 . Treatments were 1) control, grass hay only (CON) and grass hay and CSM fed once daily at 2) 0600 (EAM) 3) 1000 (MAM), or 4) 1400 (PM) . Ruminal NH3 N concentrations reflected a time of supplementation x sampling time interaction (P less than .05); CON steers had the lowest (P less than .05) ruminal NH3 N concentrations at all times other than at 0600, 1000, 1200, and 2400, when they did not differ (P greater than .05) from at least one of the supplemented groups . Forage intake, ratio of bacterial purine:N, rate of DM and NDF disappearance, and ruminal fluid kinetics were not influenced (P greater than .05) by supplementation time . Total ruminal VFA differed (P less than .05) between CON and supplemented steers, as well as among supplemented steers (linear and quadratic effects P less than .05) . Acetate, propionate, and valerate proportions were influenced (P less than .05) by a sampling time X supplementation time interaction . Under the conditions of this study, greater peak ammonia concentrations with morning supplementation than with afternoon supplementation did not stimulate ruminal fermentation or rate of NDF disappearance.

Curr Genet, 1991 Sep, 20(4), 269 - 76
Polymeric genes MEL8, MEL9 and MEL10--new members of alpha-galactosidase gene family in Saccharomyces cerevisiae; Naumov G et al.; We used a combination of genetic hybridization analysis and electrokaryotyping with radioactively labelled MEL1 gene probe hybridization to isolate and identify seven polymeric genes for the fermentation of melibiose in strain CBS 5378 of Saccharomyces cerevisiae (syn . norbensis) . Four of the MEL genes, i.e . MEL3, MEL4, MEL6 and MEL7, were allelic to those found in S . cerevisiae strain CBS 4411 (syn . S . oleaginosus) whereas three genes, i.e . MEL8, MEL9 and MEL10 occupied new loci . Electrokaryotyping showed that all seven MEL genes in CBS 5378 were located on different chromosomes . The new MEL8, MEL9 and MEL10 genes were found on chromosomes XV, X/XIV and XII, respectively.

J Chromatogr, 1991 Aug 30, 555(1-2), 272 - 7
Application of ligand-exchange chromatography to the assay of L-alanine from DL-aspartic acid by Pseudomonas dacunhae; Cheng CY et al.; A direct chiral ligand-exchange chromatographic method was developed to monitor L-alanine production by fermentation . A mobile phase containing aqueous 0.25 mM Zn2+ solution is utilized to separate amino acids in the fermentation medium . The detection limit for L-alanine is 0.5 ppm and the analysis time for one sample is about 8 min . As sample preparation is simple and the matrix effects are minimal, the assay is fast and convenient . The results indicate that the method has potential for the analysis of complicated fermentation media.

Philos Trans R Soc Lond B Biol Sci, 1991 Aug 29, 333(1267), 249 - 54; discussion 254-5
Optimization of gut structure and diet for higher vertebrate herbivores; Alexander RM; A generalized herbivore gut is modelled as (i) a well-stirred anterior chamber in which microbial fermentation occurs; (ii) a tubular reactor in which digestion but no fermentation occurs; and (iii) a posterior fermentation chamber . The rate at which the herbivore gains metabolizable energy is calculated for diets that can be eaten at different rates and contain different energy densities of easily digested cell contents, and of cell wall materials that can be fermented but not digested . The optimum gut structure for each diet is determined . Chewing probably speeds digestion and fermentation but reduces eating time . Optimal chewing times are determined for particular diets and guts . Herbivores often have a choice between poorer food that can be eaten fast and richer food that can only be eaten more slowly . Energy costs may be incurred in travelling between patches of the richer food . Optimal diet choices are predicted for herbivores with particular gut structures.

Biochem Pharmacol, 1991 Aug 22, 42(6), 1237 - 40
Mitochondrial activity and cytotoxicity of vitamin A (retinol) in yeast and human cell cultures . Protective effect of antioxidants; Cheng LL et al.; Vitamin A inhibited the growth of yeast and human cells in a dose-dependent but selective manner in cultures utilizing a non-fermentable carbon and energy source . At sub-inhibitory concentrations in yeast cultures (approximately 100 micrograms/mL), the vitamin had a stimulatory effect on the mitochondrial system, foreshortening the lag phase in the adaptation to non-fermentable substrate . At inhibitory concentrations, vitamin A depressed mitochondrial protein synthesis relative to cytoplasmic protein synthesis and induced the mitochondrial mutation petite but had little or no mutagenicity with respect to nuclear genes at the concentrations used . The vitamin showed a dose-dependent cytotoxicity (lethality) in both yeast and human cells . All of these deleterious effects were overcome to a large extent by the presence of antioxidants implicating free-radical metabolites in much of the toxicity.

Acta Paediatr Scand, 1991 Aug-Sep, 80(8-9), 792 - 4
Low breath hydrogen production in post-diarrheic infants; Joseph F Jr et al.; Thirty hospitalized infants, aged 1 month to 15 months, who were more than 24 hours into a post-recovery period from diarrheic episodes were studied for breath hydrogen production due to intestinal lactulose fermentation . Only 16% of the infants demonstrated hydrogen production of greater than 20 parts per million (ppm) over the baseline . We conclude that a recovery period much longer than 24 hours from the last diarrheic episode is necessary to obtain any reliable data from breath hydrogen tests administered to infants.

Dig Dis Sci, 1991 Aug, 36(8), 1151 - 3
Secretory diarrhea following a dog bite; Peek RM Jr et al.; Overwhelming sepsis is rarely complicated by secretory diarrhea . We present a case of fulminant sepsis associated with dermatologic manifestations, disseminated intravascular coagulation (DIC), and a severe secretory diarrhea that has not previously been described . This followed a dog bite, and the patient was otherwise healthy . The combination of septic shock, skin lesions, and DIC occurring after a dog bite has been attributed to dysgonic fermentor 2 organisms, now called Capnocytophaga canimorsus, but none were cultured in this case (7) . Dysgonic fermentor-2 may be a new cause of secretory diarrhea and should be considered in the differential diagnosis of overwhelming sepsis associated with diarrhea.

Gastroenterology, 1991 Aug, 101(2), 360 - 7
Intestinal absorption of fructose in the rat; Fujisawa T et al.; The objective of this study was to investigate the mechanisms involved in intestinal absorption of fructose . The results indicate that adult rats readily absorbed 0.4 g of fructose, an amount equivalent to 1.4-1.6 g fructose/kg body wt . Acute malabsorption of fructose occurred with doses greater than 0.6 g (2.1-2.4 g/kg body wt) . Continued exposure to dietary fructose resulted in a decrease in the evidence of colonic fermentation . Glucose or galactose administered with fructose enhanced the absorption of fructose . The greatest absorption was observed when equal amounts of fructose and glucose were given simultaneously . If glucose was ingested as a polymer (starch or dextrin), the stimulatory effect was dependent on the digestibility of the polymer . Sucrose given with the fructose and glucose diminished the absorption of fructose . Acarbazone, a specific inhibitor of alpha-glucosidases, including sucrase, also inhibited the facilitating effect of glucose and galactose in absorption of fructose . These results give evidence for joint absorption of the two monosaccharides, fructose and glucose.

Trends Biochem Sci, 1991 Aug, 16(8), 310 - 4
Adaptive responses to oxygen limitation in Escherichia coli; Spiro S et al.; Escherichia coli can grow under either aerobic or anaerobic conditions, deriving energy from a variety of respiratory of fermentative processes . The switch between different metabolic modes depends on the availability of oxygen or alternative electron acceptors, and it is controlled by regulatory mechanisms which ensure that the most energetically favourable metabolic mode is adopted in a specific environment . This article reviews the properties of two transcriptional regulators, ArcA and FNR, which control the expression of networks of genes in response to oxygen limitation.

Appl Biochem Biotechnol, 1991 Aug, 30(2), 121 - 8
An effectiveness factor you can see . Experimental visualization of the effectiveness factor concept in a biological system; Sola C et al.; Effectiveness factor values corresponding to carrageenan immobilized yeast beads packed in a continuous tubular fermenter are obtained from the mathematical modelization of the reactor performing ethanol fermentation . Simultaneously, microscopical direct observation of transversal sections corresponding to two different points in the fermenter is in good agreement with the calculated values: An effectiveness factor near to unity gives a uniform cell distribution in beads, as an effectiveness factor near to 0.75 corresponds to a non-uniform cell growth in beads . This observation gives a visual evidence of the validity of the approach used to treat diffusional limitations in biocatalytic particles.

J Dairy Sci, 1991 Aug, 74(8), 2563 - 72
The response of lactating dairy cows to increasing levels of whole roasted soybeans; Knapp DM et al.; Twenty-four Holstein cows, including four primiparous and four ruminally cannulated, were in replicated 4 x 4 Latin squares with 21-d periods to determine the effects of feeding level of whole roasted soybeans on lactation performance and rumen function . Cows were fed rations containing a 50:50 forage:concentrate ratio with 0, 12, 18, or 24% of diet DM as whole roasted soybeans . Rations contained 16.8, 16.9, 18.6, and 19.7% CP and 1.68, 1.71, 1.72, and 1.74 Mcal NEL/kg DM, respectively . Milk production and milk fat percentages for diets containing 0, 12, 18, or 24% whole roasted soybeans were 34.9, 37.5, 38.5, and 38.8 kg/d and 3.23, 3.20, 3.32, and 3.37%, respectively . Milk protein percentage was depressed at all levels of whole roasted soybeans . Ruminal pH, VFA molar percentages except valerate, and DM disappearance of forage from dacron bags did not differ among treatments . Responses were similar among primiparous and multiparous cows . Results suggest benefit from feeding whole roasted soybeans at levels up to 18% of ration DM without adversely affecting DMI, milk fat, or rumen fermentation.

Biotechnol Appl Biochem, 1991 Aug, 14(1), 82 - 92
Efficient production of recombinant DNA proteins in Saccharomyces cerevisiae by controlled high-cell-density fermentation; Alberghina L et al.; High levels of expression of heterologous proteins (from 5 to 15% of total cell proteins) in the budding yeast Saccharomyces cerevisiae have been obtained previously by the use of the inducible strong hybrid promoter UASGAL/CYC1, in batch as well in continuous cultures . However, in order to maximize the yield of heterologous proteins, a computer controlled fed-batch fermentation is essential . For this reason we have developed a fed-batch system based on a semiconductor gas detector that measures ethanol in the outflow gases . The optimal conditions are described for very high production (up to 1550 mg/liter), with both high productivity (up to 100-120 mg/liter/h) and high yield (up to 15 mg of protein/g of dry biomass), of heterologous protein driven by the UASGAL/CYC1 promoter in a completely computer controlled fed-batch fermentation of budding yeast . However, high production was dependent upon the addition of a large amount of galactose . The process was improved by developing a new, more easily inducible, vector system obtained by subcloning the GAL4 gene.

J Anim Sci, 1991 Aug, 69(8), 3425 - 34
Evaluation of dairy food processing wash water solids as a protein source: III . Nitrogen utilization by heifers fed medium-concentrate diets; May T et al.; Eight multicannulated heifers (average BW 415 +/- 34 kg) were used in a replicated 4 x 4 Latin square to evaluate fluid milk processing wash water solids (WWS) as a dietary N source . Heifers were fed corn/cottonseed hull-based diets containing soybean meal (control, 0% WWS N) or WWS replacing soybean meal at 33, 67, or 100% of supplemental dietary N . Total tract and ruminal DM and OM digestibilities decreased linearly or cubically (P less than .05) as dietary WWS N increased . Total ruminal VFA concentration (P less than .05) and propionic acid molar proportion (P less than .10) were greater in heifers fed 0 vs 100% WWS N . Heifers fed 0% WWS N had the greatest (P less than .05) ruminal ammonia concentration at all sampling times . Dietary WWS did not affect (P greater than .10) ruminal pH, fluid dilution rate, fluid flow, fluid volume, or turnover time . Total tract N digestibility decreased quadratically (P less than .10) with increasing WWS N in the diet . Supplemental WWS N did not affect (P greater than .10) flow of duodenal ammonia N or bacterial N, or efficiency of microbial N synthesis . Diets containing WWS N resulted in a cubic increase (P less than .10) in duodenal flow of essential amino acids compared with 0% WWS N; however, there were no differences in small intestinal amino acid disappearance . Data indicate that WWS can replace 33% of the soybean meal N in a corn/cottonseed hull-based diet without decreasing ruminal fermentation, fluid digesta kinetics, microbial efficiency, or small intestinal amino acid utilization.

J Anim Sci, 1991 Aug, 69(8), 3416 - 24
Evaluation of dairy food processing wash water solids as a protein source: II . Microbial protein synthesis, duodenal nitrogen flow, and small intestinal amino acid disappearance; Caton JS et al.; Twelve ruminally, duodenally, and ileally-cannulated Hereford heifers (average initial BW 313 +/- 20 kg) were used in a replicated experiment to evaluate dairy food processing wash water solids (WWS) as a protein source . Heifers were fed 2.8 kg of chopped (7.6 cm) hay and one of three supplements (1.5 kg/d, DM basis) . Supplements were formulated to be similar in energy and contained 1.0 (control), 23.2 (WWS), and 21.6% (soybean meal; SBM) CP on an OM basis . Total N and nonammonia N entering the duodenum (g/d) were greater (P less than .10) for heifers fed WWS and SBM supplements than for controls . Bacterial N flow (g/d) at the duodenum was less (P less than .10) for controls (43.9) than for WWS- (63.9) and SBM- (69.9) supplemented heifers . Feed escape N (g/d) was greater (P less than .10) for WWS-fed heifers than for those fed SBM (32.1 vs 20.7 g/d, respectively) . Total tract N digestion (g/d) was greatest (P less than .10) for SBM, intermediate for WWS, and least for control heifers . Microbial protein synthesis (g/kg of OM intake) was enhanced (P less than .10) by WWS and SBM supplementation, but efficiency of synthesis (g/kg of OM fermented) did not differ among treatments . Essential amino acid (AA) disappearance in the small intestine (g/d) was less (P less than .10) for control than for the other two treatments . Nonessential AA disappearance was greatest (P less than .10) for the WWS and least (P less than .10) for the control treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Mol Gen Genet, 1991 Aug, 228(1-2), 167 - 76
Mitochondrial inner membrane protease 1 of Saccharomyces cerevisiae shows sequence similarity to the Escherichia coli leader peptidase; Behrens M et al.; The nuclear yeast mutant pet ts2858 is defective in the removal of pre-sequences from the mitochondrially encoded cytochrome oxidase subunit II (COXII) and the processing intermediate of cytochrome b2 (Cytb2), a nuclear gene product . In order to identify the genetic lesion in this mutant we have cloned and characterized a DNA region which complements the pet ts2858 mutation . The DNA sequence revealed three open reading frames, one of which is responsible for the complementation . A 570 bp reading frame represents the structural gene PET2858, as demonstrated by in vitro mutagenesis, gene expression from a foreign promoter, and allelism tests . PET2858 encodes a 21.4 kDa protein, which is essential for growth on non-fermentable carbon sources and for the proteolytic processing of COXII and the Cytb2 intermediate . When the N-terminus of the PET2858 protein is fused to a reporter protein, the resulting hybrid molecule is imported into mitochondria . Interestingly, the N-terminal half of the deduced PET2858 protein exhibits 30.7% amino acid identity to the leader peptidase of Escherichia coli . These results suggest that PET2858 codes for a mitochondrial inner membrane protease (IMP1) or at least a subunit of it . This protease is involved in protein processing and export from the mitochondrial matrix.

Antibiot Khimioter, 1991 Aug, 36(8), 10 - 3
{Activity of glycolysis enzymes in cyclosporine-producing Tolypocladium sp.}; Sotnikova IV et al.; Enzymes of various glycolysis stages, i.e . hexokinase, phosphofructokinase, pyruvate kinase and lactate dehydrogenase, were detected in cyclosporine-producing organisms belonging to Tolypocladium . The initial activity of the enzymes in the highly active strain was much higher than that in the starting low active strain . During the fermentation the activity of the glycolysis enzymes per 1 mg of mycelium protein in the both strains increased . This was accompanied by a decrease in respiration activity . Therefore, there was a direct correlation between cyclosporine biosynthesis and glycolytic activity of the mycelium in Tolypocladium sp.

Oral Microbiol Immunol, 1991 Aug, 6(4), 250 - 5
Aspects of the growth and metabolism of Fusobacterium nucleatum ATCC 10953 in continuous culture; Rogers AH et al.; Fusobacterium nucleatum ATCC 10953, a type strain of one of the newly proposed subspecies of this group of organisms, was grown anaerobically in continuous culture in a chemically defined medium . Its response to conditions of varying pH, nutritional environment, and imposed growth rate were then examined . The organism failed to grow at pH 7.8 but grew at pH 5.8, although the cell yield was greatly reduced . At pH 6.8 the cell yield was halved and less than 50% of available glucose was consumed . The optimum growth pH was around 7.4 when the culture appeared to be limited for both glucose and the amino acids glutamate, histidine and serine . Some intracellular polyglucose (IP) was produced and acetate, butyrate and ammonia were the major fermentation end-products, as they were under all growth conditions tested . Increasing the available glucose or amino acids did not alter cell numbers but the amount of IP was greatly increased . When glucose was omitted from the medium, the cell yield was halved and the culture then became limited for lysine as well as for glutamate, histidine and serine . Growth rate had little overall effect on the organism's physiology and the maximum growth rate at pH 7.4 was 0.20 h-1, a doubling time of 3.5 h . Glucose was thus channelled into stable IP synthesis only when the growth limitation imposed by lack of fermentable amino acids was relieved . The metabolism of IP and the ability to obtain carbon and energy from a variety of substrates may explain why F . nucleatum is one of the most commonly detected organisms in subgingival dental plaque.

Stomatol Glas Srb, 1991 Aug-Oct, 37(4), 409 - 24
{Adentol (natural sweetener) and caries prevention}; Vulovic M et al.; Numerous epidemiological, experimental and clinical studies have established, without doubt, the correlation between the consumption of dietary sugars and caries prevalence . The increase of the sugar consumption in Yugoslavia is in direct correlation with caries activity in children . One of the aims of preventive programmes is to improve the diet habits through the use of non-cariogenic sugar substitutes . Adentol is a hydrogenated glucose syrup obtained from the enzymic hydrolysis of corn starch, made by D.P.,"HPK" Bosanska Dubica-Yugoslavia . Its chemical content is very similar to that of Lycasin 80/55 (Roquette Freres-France) . Published data on its behaviour in acid production in vitro and in dental plaques, its effect on the oral microorganisms and the process of remineralization of initial caries lesions, suggest that hydrogenated glucose syrup (Lycasin, Adentol) is less fermentable in oral cavity and without cariogenic properties . Substitution of dietary sugars by Adentol in confectionery and syrup medicines is likely to be of significant benefit to dental health.

Anal Biochem, 1991 Aug 1, 196(2), 451 - 5
High-performance liquid chromatographic determination of alpha-acetyldigoxin in Digitalis lanata leaves; Ikeda Y et al.; An analytical method for the determination of alpha-acetyldigoxin in Digitalis lanata leaves by HPLC has been developed . The procedure consists of extraction of dry leaf powder with 50% methanol and cleanup by a Sep-Pak C18 cartridge prior to HPLC analysis . The quantitation is carried out by the incorporation of beta-methyldigoxin as an internal standard . HPLC is performed on an octylsilyl bonded silica column with acetonitrile/methanol/water (100/11/188, v/v) . The effluent is monitored by uv absorption at 220 nm . The amount of alpha-acetyldigoxin per 100 mg of dry leaf powder is estimated at 5.55 +/- 0.21 micrograms (mean +/- SD) . The average recovery of alpha-acetyldigoxin from added samples is 97.2% . The present method is sensitive, reliable, and relatively simple . Application of this HPLC method to the analysis of samples obtained by fermentation of the leaf powder is also demonstrated.

Yeast, 1991 Aug-Sep, 7(6), 539 - 46
The determinants of heat-shock element-directed lacZ expression in Saccharomyces cerevisiae; Kirk N et al.; Heat-shock induction of heat-shock protein genes is due to a specific promoter element (the heat-shock element, HSE) . This study used lacZ under HSE control (HSE-lacZ) to characterize HSE activity in Saccharomyces cerevisiae cells of different physiological states and differing genetic backgrounds . In batch fermentations HSE-lacZ induction by heat shock was maximal in exponential growth, and showed marked decline with the approach to stationary phase . Expression in the absence of heat shock was unaffected by growth phase, indicating that the growth-dependent expression of many yeast heat-shock genes uses promoter elements in addition to the HSE . Heat-induced expression was strongly influenced by the temperature at which cultures were grown . While basal, uninduced expression was constant during growth at different temperatures to 30 degrees C, induction by transfer to 39 degrees C was reduced by increases in growth temperature as low as 18-24 degrees C . Maximal HSE-lacZ induction (30- to 50-fold) was in cultures grown at low temperatures (18-24 degrees C), then heat shocked at 39 degrees C . Ethanol was a poor inducer . Mutations having little effect on HSE-lacZ expression included a respiratory petite; ubi4 (which inactivates the poly-ubiquitin gene); also ubc4 and ubc5 (which each inactivate one of the ubiquitin ligases involved in degradation of aberrant protein) . pep4-3 increased both basal and induced beta-galactosidase about two-fold, probably because of slower turnover of this enzyme in pep4-3 strains.

Antibiot Khimioter, 1991 Aug, 36(8), 6 - 10
{Various methodological approaches in controlled screening of antibiotic producers among the group of Coryneform bacteria}; Obgol'tseva IO et al.; A methodical system for directed screening of cultures producing broad-spectrum antibiotics among soil saprophytic coryneform bacteria was developed . To isolate such cultures, it was recommended to use the glucose-yeast medium supplemented with malt extract (No . 18/3) and soybean-glucose medium with sodium sulfate and cobalt chloride (No . 20/3) . The preliminary alkaline treatment of the soil substrates and the use of acidic soil samples were found to favour isolation of the Mycobacterium type cultures . It was recommended to use gram-negative tests microbes with relatively low antibiotic resistance for screening cultures producing broad spectrum antibiotics . Various agarized and liquid fermentation media were compared in regard to detection of antibiotic activity in the soil coryneform bacteria . The corn medium supplemented with protein-vitamin concentrate, glucose, lactose and starch (No . 116) proved to be the most efficient.

Antibiot Khimioter, 1991 Aug, 36(8), 13 - 7
{Cytomorphological and cultural characteristics of tylosin-producing strains with different antibiotic activity}; Tikhomirova LA et al.; Cytomorphological and cultural characteristics of highly and low active collection strains of Streptomyces fradiae producing tylosin were studied . The strains were grown on agarized and liquid media . It was shown that unlike the low active strain, the highly active one was less sporogenic, the difference being more pronounced when tylosin was added to the agarized medium . When the strains were grown in the fermentation medium there were detected differences between them in the growth type and microcolony structure at the early stages of the fermentation process . During intensive synthesis of tylosin spheric structures were found to form near the hyphal surfaces . The phenomenon was previously observed in cultures producing other antibiotics . In the low active strain the structures were single while in the highly active strain they formed in large numbers.

J Dairy Sci, 1991 Aug, 74(8), 2724 - 7
Effects of isoacids, urea, and sulfur on ruminal fermentation in sheep fed high fiber diets; Brondani A et al.; The effects of isoacids, urea N, and S on ruminal fermentation of sugarcane bagasse- or corn stover-based diets were studied in sheep . Acetate production was taken as a measure of the fermentation rate . For the sugarcane bagasse diet, neither urea nor S supplementation changed ruminal acetate production . When N and S were combined, acetate production was 44% higher (3.16 vs . 2.18 mol/d) . Similar effects were noted for the corn stover diet . Increasing the level of isoacids from .1 to .2 g/kg BW per d in the diet did not change acetate production for either diet . However, N supplementation of the sugarcane bagasse diet containing the low level of isoacids resulted in a 49% greater acetate production (2.86 vs . 1.91 mol/d) . Acetate production was 90% higher (3.74 vs . 1.97 mol/d) when the diet containing the high level of isoacids was supplemented with N . The corresponding increases for corn stover were 12% (2.64 to 2.95 mol/d) and 35% (2.88 to 3.87 mol/d) . The results suggest that NH3 N provided by the basal diet was more limiting than isoacids . Once the N deficiency was corrected, isoacids became limiting . Ruminal digestion of high fiber diets low in N was improved by supplementation with urea, isoacids, and S.

J Am Coll Nutr, 1991 Aug, 10(4), 364 - 71
Effect of method of administration of psyllium on glycemic response and carbohydrate digestibility; Wolever TM et al.; To determine whether there was any advantage to taking a soluble fiber supplement separate from food, as opposed to incorporated into a food, we used psyllium as a model, either taken in water just before a flaked bran cereal test meal, sprinkled on top of the cereal, or actually incorporated into the flake . In normal subjects, psyllium reduced the glycemic response when sprinkled onto or incorporated into the cereal, but not when taken before the cereal . Varying the amount of psyllium incorporated into the cereal from 0 to 20% resulted in a linear dose-dependent reduction of the glycemic index (GI) (GI = 101 -2.2 x % psyllium; r = 0.950; p less than 0.002) . In subjects with diabetes, the blood-glucose-lowering effect of the psyllium flake cereal was similar to that in normal subjects . Mixing psyllium with the cereal or incorporating it into the cereal reduced the rate of digestion of bran flakes in vitro but was not associated with increased breath hydrogen levels in vivo as an index of rapid colonic fermentation . The bran flakes with psyllium incorporated was rated as no less palatable than the bran flakes cereal alone, and significantly more palatable (p less than 0.05) than taking psyllium in water before the cereal or sprinkling psyllium onto the cereal . These studies confirm earlier reports that viscous fibers must be intimately mixed with the food to have the effect of reducing blood glucose responses, and that the mechanism of action relates to a reduced rate of digestion rather than carbohydrate malabsorption.(ABSTRACT TRUNCATED AT 250 WORDS)

J Anim Sci, 1991 Aug, 69(8), 3406 - 15
Evaluation of dairy food processing wash water solids as a protein source: I . Forage intake, animal performance, ruminal fermentation, and site of digestion in heifers fed medium-quality hay; Caton JS et al.; Twelve ruminally, duodenally, and ileally cannulated (average initial BW 313 +/- 20 kg) and 27 intact Hereford heifers (average initial BW 256 +/- 17 kg) were used in two experiments to evaluate dairy food wash water solids (WWS) as a protein source in medium-quality hay diets . Heifers received a basal diet of orchardgrass hay (7.4% CP) and were assigned to one of three supplement treatments: control (C; .9% CP), WWS (18.8% CP)-, and soybean meal (SBM; 19.1% CP)-based supplements (fed at 1.5 kg of DM/d) . Supplements were formulated to have similar ME concentrations . Ruminal ammonia concentrations were greater (P less than .10) for WWS- and SBM-supplemented heifers than for C heifers at most sampling times . Moreover, WWS and SBM increased (P less than .10) total VFA (mM) and acetate (mol/100 mol) and lowered propionate (mol/100 mol) at several sampling times . Ruminal fluid volume (liters) was unchanged (P greater than .10) by treatment; however, fluid dilution and flow rate (liters/h) were less (P less than .10) in C heifers than in heifers fed SBM or WWS supplements . Wash water solids and SBM supplementation increased (P less than .10) OM, NDF, and ADF digestibilities compared with C heifers . Feeding WWS and SBM supplements increased BW at 84 d (P less than .10) compared with C-supplemented heifers . Forage intake at 54 and 84 d by heifers supplemented with SBM or WWS was greater (P less than .10) than by C heifers . Control-supplemented heifers had the least, WWS intermediate, and SBM the greatest ADG at 84 d (P less than .10; .14 vs .35 vs .48 kg/d, respectively) . These data indicate that WWS may be used as a protein source without serious adverse effects in heifers consuming medium-quality hay for 84 d.

J Bacteriol, 1991 Aug, 173(16), 4909 - 13
Identification of two porins in Pelobacter venetianus fermenting high-molecular-mass polyethylene glycols; Schmid A et al.; Porins were purified from cells of the anaerobic gram-negative bacterium Pelobacter venetianus grown with 20-kDa polyethylene glycol . After treatment of the cell envelope fraction with sodium dodecyl sulfate-containing solutions, the murein contained only two major peptidoglycan-associated proteins of 14 and 23 kDa . Both proteins were released from the peptidoglycan by the detergent Triton X-100 . Genapol X-80 released only the 23-kDa protein . This protein was purified by chromatography on a hydroxyapatite column . It did not form sodium dodecyl sulfate-resistant oligomers . Reconstituted in lipid bilayer membranes, the 23-kDa protein formed cation-selective channels with a single-channel conductance of 230 pS in 1 M KCl . The channel is not a general-diffusion pore, since its conductance depends only moderately on the salt concentration . The channel conducted ammonium much better than potassium or rubidium ions, suggesting that it is probably involved in ammonium uptake . The outer membrane of P . venetianus contains a further, non-murein-associated pore with an unknown molecular mass . It is also cationically selective and has a single-channel conductance of 1.6 nS in 1 M KCl, which suggests that its effective diameter is similar to that of porins from enteric bacteria.

EMBO J, 1991 Aug, 10(8), 2095 - 104
A yeast homologue of the bovine lens fibre MIP gene family complements the growth defect of a Saccharomyces cerevisiae mutant on fermentable sugars but not its defect in glucose-induced RAS-mediated cAMP signalling; Van Aelst L et al.; Recently a new family of membrane proteins comprising the bovine lens fibre major intrinsic protein, soybean nodulin-26 protein and the Escherichia coli glycerol facilitator has been described {M.E . Baker and M.H . Saier, Jr (1990) Cell, 60, 185-186} . These proteins have six putative membrane spanning domains and one (probably intracellular) intermembrane fragment is particularly well conserved . We have identified a new member of this family in the yeast Saccharomyces cerevisiae . It also possesses the six transmembrane domains and the highly conserved intermembrane sequence . In contrast to the other three proteins which are all approximately 280 amino acids long, the yeast protein has an N-terminal extension of approximately 250 amino acids, which contains a string of 17 asparagine residues and a C-terminal extension of approximately 150 amino acids . The gene, which we called FPS1 (for fdp1 suppressor), suppresses in single copy the growth defect on fermentable sugars of the yeast fdp1 mutant but it is not allelic to FDP1 . The deficiency of the fdp1 mutant in glucose-induced RAS-mediated cAMP signalling and in rapid glucose-induced changes in the activity of certain enzymes was not restored . Deletion of FPS1 does not cause any of the phenotypic deficiencies of the fdp1 mutant.

EMBO J, 1991 Aug, 10(8), 2023 - 31
ABC1, a novel yeast nuclear gene has a dual function in mitochondria: it suppresses a cytochrome b mRNA translation defect and is essential for the electron transfer in the bc 1 complex; Bousquet I et al.; We have cloned and sequenced a novel yeast nuclear gene ABC1 which suppresses, in multicopy, the cytochrome b mRNA translation defect due to the nuclear mutation cbs2-223 . Analysis of the ABC1 gene shows that it is weakly expressed, it could code for a protein of 501 amino acids which has a typical presequence of a protein imported into mitochondria and which does not display a strong similarity to any known protein . Inactivation of the ABC1 gene is not lethal to the cell but leads to a respiratory defect: no oxygen uptake and no growth on non-fermentable media . A total absence of NADH-cytochrome c oxidoreductase and succinate-cytochrome c oxidoreductase activities concomitant with the presence of specific dehydrogenases, suggests a block in the bc 1 segment of the respiratory chain . However, all the cytochromes are spectrally detectable . Cytochrome b is quite efficiently reduced while cytochromes c1 and c are not . The function of ABC1 in the suppression of a defect in apocytochrome b mRNA translation and in the activity of the bc1 complex suggests that the ABC1 protein would be a novel chaperonin involved both in biogenesis and bioenergetics of mitochondria.

Appl Microbiol Biotechnol, 1991 Aug, 35(5), 622 - 30
Inactivation of recombinant plasmid DNA from a human erythropoietin-producing mouse cell line grown on a large scale; Fibi MR et al.; Experiments were carried out to assess the survival of recombinant plasmid DNA during large-scale production of recombinant human erythropoietin (rhuEPO) in a fermentation pilot plant . The analyses revealed DNA-degrading activities in the fermentation broth and in the waste-water, leading to rapid destruction of plasmid DNA added to medium or waste-water . The capability of the plasmid-DNA-spiked samples to transform competent bacteria was drastically reduced . The DNA-degrading activity in the waste-waters could be blocked by addition of EDTA or by boiling, indicating the presence of DNA-degrading enzymes (DNases) . No plasmid-specific DNA sequences were detected in waste-water samples by in-vitro amplification with Taq-polymerase . Genomic DNA preparations of cell debris collected from waste-water samples only contained degraded plasmid DNA . Furthermore, it was shown that intact plasmid DNA could be degraded to fragments of less than 1000 bp by incubation at 121 degrees C for 20 min, leading to a decrease in the plasmid-specific transforming capacity by a factor of 10(3) per minute . Thus, DNA from the rhuEPO production pilot plant was efficiently inactivated at three different levels: (i) in the fermentation medium (DNase), (ii) in the waste-water container (DNase), and (iii) by heat inactivation for 20 min at 120 degrees C . These results indicate that the probability of delivery of recombinant DNA into the environment is extremely low in such biotechnological production processes.

Trends Biotechnol, 1991 Aug, 9(8), 273 - 8
The kinetics of plasmid loss; Summers DK; Instability of bacterial cloning vectors can present a serious problem when direct selection for plasmid-encoded phenotypes is undesirable, ineffective or impractical . Antibiotic selection may provide a satisfactory solution in enclosed fermentors but not where recombinant organisms are part of complex microbial consortia after release into the outside environment . In the past decade there has been significant progress towards understanding the causes of plasmid loss and the lessons learned from these studies can be used in the design of a new generation of stable vectors.

Biochem Biophys Res Commun, 1991 Jul 15, 178(1), 132 - 7
An endothelin receptor (ETA) antagonist isolated from Streptomyces misakiensis; Ihara M et al.; A competitive endothelin (ET) antagonist, BE-18257B, was isolated from the fermentation products of Streptomyces misakiensis . It is a novel cyclic pentapeptide, cyclo(-D-Glu-L-Ala-allo-D-Ile-L-Leu-D-Trp-), and binds to ETA receptors (ET-1 selective) in cardiovascular tissues, but not to ETB receptors (equally sensitive to isopeptides of ET family) in kidney, adrenal gland and cerebellum tissues . BE-18257B also antagonizes ET-1-induced vasoconstriction in rabbit iliac artery and pressor action in rats . Thus it is a selective ETA antagonist and should provide a valuable tool for elucidation of the pharmacological and pathophysiological roles of ET-1.

Am J Clin Nutr, 1991 Jul, 54(1), 141 - 7
Specific types of colonic fermentation may raise low-density-lipoprotein-cholesterol concentrations; Jenkins DJ et al.; To assess the effects of increased colonic fermentation on serum lipids, eight healthy volunteers were placed on two identical 2-wk metabolic diets, one of which was supplemented with lactulose (18-25 g/d) . Lactulose raised day-long concentrations of breath hydrogen and serum glutamine as indicators of increased colonic fermentation by 78 +/- 13% (P less than 0.001) and 24.7 +/- 9.5% (P less than 0.05), respectively) . Unexpectedly, however, fasting serum total and low-density-lipoprotein cholesterol and apolipoprotein B concentrations were higher at 2 wk by 8.9 +/- 1.5% (P less than 0.001), 10.9 +/- 2.2% (P less than 0.005), and 18.9 +/- 5.9% (P less than 0.02), respectively, compared with the control diet . With lactulose, mean free fatty acid concentrations were reduced over the day by 19.5 +/- 5.9% (P less than 0.02), with no change in mean day-long blood glucose, serum insulin, or C-peptide concentrations . We conclude that certain rapidly fermented substrates may raise rather than lower serum lipids, possibly through increasing the amount of acetate absorbed from the colon.

Mol Cell Biol, 1991 Jul, 11(7), 3762 - 72
Complex transcriptional regulation of the Saccharomyces cerevisiae CYB2 gene encoding cytochrome b2: CYP1(HAP1) activator binds to the CYB2 upstream activation site UAS1-B2; Lodi T et al.; Expression of the Saccharomyces cerevisiae gene encoding cytochrome b2 (EC 1.2.2.3), CYB2, was investigated by direct analysis of mRNA transcripts and by measurement of the expression of lacZ fused to the CYB2 control regions . These studies indicated that regulation of the CYB2 gene is subject to several metabolic controls at the transcriptional level: inhibition due to glucose fermentation, induction by lactate, and inhibition in anaerobiosis or in absence of heme biosynthesis . Furthermore, we have shown that the CYB2 promoter contains one cis negative regulatory region and two heme-dependent positive regions, one of which is controlled by the transcriptional regulator CYP1 (HAP1) which is involved in the modulation of the expression of several oxygen-regulated genes . The CYP1 (HAP1)-binding sequence was located by gel retardation and DNase I footprinting experiments and compared with the binding sequences previously characterized in detail (UAS1CYC1, UAS'CYP3 (CYC7), and UASCTT1).

J Gen Microbiol, 1991 Jul, 137 ( Pt 7), 1759 - 64
Description of two anaerobic fungal strains from the bovine rumen and influence of diet on the fungal population in vivo; Kostyukovsky VA et al.; Neocallimastix sp . NC71 and Piromyces sp . PC12 isolated from the calf remen grew optimally at 39 degrees C and pH 6.5-6.7, utilized a wide range of mono-, oligo- and polysaccharides and exhibited CMCase, Avicelase, cellobiase, amylase and xylanase activities . The end-products of wheat straw fermentation by both strains were acetate, formate, ethanol and lactate . The number of Neocallimastix sp . zoospores in the rumen of cows in the first 3 h after feeding with hay-silage-concentrate diets varied from 7 x 10(3) to 5.4 x 10(5) ml-1; the number of uniflagellate zoospores varied from 10(4) to 10(5) ml-1 . Fungal zoosporgenesis and colonization of plant substrates in the rumen were induced by feed intake and were favoured by increased levels of crude fibre in the diet.

Antibiot Khimioter, 1991 Jul, 36(7), 32 - 4
{Alimentary methods of maintaining the superoxide dismutase activity in the tissues of rats during growth of a transplanted tumor and administration of carminomycin}; Lenskaia EG et al.; The aim of the experiment was to study the effect of three specialized food rations on activity of superoxide dismutase (SOD) in tissues of rats with transplanted Walker's carcinosarcoma 256 exposed to carminomycin . It was shown that the three specialized rations were able to significantly modify the SOD activity in the tissues of the rats with Walker's carcinosarcoma 256 at the background of treatment with carminomycin . Thus, the ration enriched with copper and zinc salts and folic acid activated SOD in the animals of all the groups . Still, the effect was higher in the tumor-bearing animals and the rats treated with carminomycin i.e . under conditions of oxidative stress . The use of the ration enriched with sulfur-containing amino acids, sodium selenide and vitamin E led to decreasing of the efficiency of the fermentative dismutation of O2 in the healthy rats and marked activating of SOD in the tumor-bearing animals . The ration containing lyophilized vegetables and vitamin E provided a significant increase in the SOD activity in the healthy rats . However, its potential was not sufficient for overcoming the SOD inhibiting effect of the tumor growth.

Appl Biochem Biotechnol, 1991 Jul, 30(1), 99 - 109
Optimization of cellulase production by Aspergillus niger NCIM 1207; Gokhale DV et al.; Aspergillus niger NCIM 1207 produces high levels of extracellular beta-glucosidase and xylanase activities in submerged fermentation . Among the nitrogen sources, ammonium sulfate, ammonium dihydrogen orthophosphate, and corn-steep liquor were the best for the production of cellulolytic enzymes by A . niger . The optimum pH and temperature for cellulase production were 3.0-5.5 and 28 degrees C, respectively . The cellulase complex of this strain was found to undergo catabolite repression in the presence of high concentrations of glucose . Glycerol at all concentrations caused catabolite repression of cellulase production . The addition of glucose (up to 1% concentration) enhanced the production of cellulolytic enzymes, but a higher concentration of glucose effected the pronounced repression of enzymes . Generally the growth on glucose- or glycerol-containing medium was accompanied by a sudden drop in the pH of the fermentation medium to 2.0.

Zh Mikrobiol Epidemiol Immunobiol, 1991 Jul, (7), 14 - 7
{The hydrogen peroxide microvolumetric method of the OF test: the rapid determination of glucose oxidation and fermentation by gram-negative bacteria}; Sivolodskii EP; For the first time the method of the rapid (1 hour) screening of groups of gram-negative bacteria by the OF test with glucose, carried out with the use of microvolumetric techniques, has been developed . The method is based on the use of hydrogen peroxide at non-bactericidal concentration as a component of a liquid buffer medium containing indicator and glucose and intended for the oxidation of glucose . Catalase of bacteria introduced into the medium for study ensures the rapid saturation of the medium with oxygen and the completion of the oxidation of glucose in 10-60 minutes . An equal period is necessary to achieve the complete fermentation of glucose in the same medium without hydrogen peroxide . The method has been proved to yield significant results in the joint study of the OF test on 502 strains, belonging to 21 genera of fermenting and nonfermenting gram-negative bacteria, by the hydrogen peroxide method and in Hugh-Leifson medium.

J Anal Toxicol, 1991 Jul-Aug, 15(4), 216 - 9
Scopolamine poisoning from homemade 'moon flower' wine; Smith EA et al.; LH, a 76-year-old Caucasian male, ingested 3 teaspoons (15 mL) of a homemade wine over a 1-h period and became ill . Approximately 1.5 h later, he was taken to the emergency room of a local hospital with symptoms of respiratory distress and weakness . The plant used in making the wine was Angel's trumpet (Datura suaveolens), which reportedly contains varying amounts of scopolamine and atropine . A sample of the wine was collected and analyzed for these two compounds by reversed-phase HPLC chromatography using 97% methanol-3% deionized water . The filtered wine contained an estimated 29 mg scopolamine/mL, which produced a total ingested dose of 435 mg . No atropine was detected . The scopolamine was confirmed by TLC . An oral dose of 50 mg of atropine sulfate in humans has been reported fatal, but there is no reported fatal dose for scopolamine . The alcohol content and 3.8 pH of the homemade wine may have increased the extraction of this compound from the plant material, and the wine fermentation process may have concentrated the original extract.

Mod Pathol, 1991 Jul, 4(4), 481 - 6
The incidence and distribution of Mycoplasma fermentans (incognitus strain) in the Chicago AIDS autopsy series: an immunohistochemical study . Chicago Associated Pathologists; Miller-Catchpole R et al.; Mycoplasma incognitus is a recently described organism that was originally isolated by Shyh-Ching Lo from spleen and Kaposi's sarcoma (KS) tissue of patients with AIDS . The mycoplasm has since been found in selected AIDS autopsy cases in which there were tissues with unexplained areas of necrosis . Mycoplasma incognitus is now known to be closely related to Mycoplasma fermentans . In order to determine the incidence and distribution of M . fermentans/M . incognitus in an unselected series, we performed a retrospective immunohistochemical study of 42 HIV-positive autopsies from the Chicago AIDS autopsy series . One case (2.4%) was found to be positive . The patient was a 27-year-old white male homosexual who had no evidence of Kaposi's sarcoma nor of any other neoplastic disorder and who died of Pneumocystis carinii pneumonia . Antigen was present in the macrophages of the patient's spleen, liver, and bone marrow but was not associated with areas of necrosis . All other tissues sampled from this case (brain, heart, testis, lymph nodes) were negative . In the remaining autopsies, organs of the reticuloendothelial system as well as other randomly selected tissues (e.g., lung, heart, testis, pancreas) were screened and found to be negative . Tissues from several non-AIDS autopsies were also found to be nonreactive for M . fermentans/M . incognitus . We conclude that M . fermentans/M . incognitus is not a common agent found in the Chicago AIDS population; that it may be identified in tissue without morphologic abnormality; and that it is not randomly present in non-AIDS autopsies.(ABSTRACT TRUNCATED AT 250 WORDS)

Plant Foods Hum Nutr, 1991 Jul, 41(3), 203 - 12
Effect of soaking, sprouting, fermentation and cooking on nutrient composition and some anti-nutritional factors of sorghum (Guinesia) seeds; Obizoba IC et al.; This study was designed to determine the effect of soaking, sprouting, fermentation and cooking on nutrient composition and some antinutritional factors of sorghum seeds (guinesia) . Standard assay procedures were adopted to resolve both the nutrients and the antinutritional factors content of the products . Combination of cooking and fermentation improved the nutrient quality and drastically reduced the antinutritional factors to safe levels much greater than any of the other processing methods tested.

Mycopathologia, 1991 Jul, 115(1), 31 - 5
Effect of parboiling and bran removal on aflatoxin levels in Sri Lankan rice; Bandara JM et al.; Commercial parboiling of rice in Sri Lanka and many south Asian countries provides ideal conditions for the occurrence of aflatoxins because the rice is steeped (allowing fermentation) thus providing ideal conditions for growth of toxigenic Aspergillus species . However the traditional 'cottage' method of parboiling rice, which does not involve steeping, appears to reduce Aspergillus growth even after long storage periods . Preferential infection of parboiled rice by Aspergillus flavus was observed . Aflatoxin contents in inoculated rice produced by commercial parboiling (AFB1 60-92 mg/kg) were significantly higher than that in inoculated 'cottage' processed rice (AFB1 12-29 micrograms/kg) . The steeping (precooking/soaking) process in commercial parboiling appears to increase the susceptibility of rice grains to fungal infection . Aflatoxin content in grains increased considerably with the increase in duration of soaking . However, the addition of 10 ppm calcium hypochlorite (bleach) to soaking water appreciably reduced A . flavus contamination and subsequent aflatoxin content in parboiled rice . No significant reduction in aflatoxin levels were observed after bran removal of contaminated rice.

Comput Appl Biosci, 1991 Jul, 7(3), 327 - 36
CAMBIO: software for modelling and simulation of bioprocesses; Farza M et al.; CAMBIO, a software package devoted to bioprocess modelling, which runs on Apollo computers, is described . This software enables bioengineers to easily and interactively design appropriate mathematical models directly from their perception of the process . CAMBIO provides the user with a set of design symbols and mnemonic icons in order to interactively design a functional diagram . This diagram has to exhibit the most relevant components with their related interactions through biological and physico-chemical reactions . Then, CAMBIO automatically generates the dynamical material balance equations of the process in the form of an algebraic-differential system by taking advantage of the knowledge involved in the functional diagram . The model may be used for control design purpose or completed by kinetics expressions with a view to simulation . CAMBIO offers facilities to generate a simulation model (for coding of kinetics, introducing auxiliary variables, etc.) . This model is automatically interfaced with a specialized simulation software which allows an immediate visualization of the process dynamical behaviour under various operational conditions (possibly involving feedback control strategies) . An example of an application dealing with yeast fermentation is given.

J Antibiot (Tokyo), 1991 Jul, 44(7), 768 - 73
Thiazocins, new aldose reductase inhibitors from Actinosynnema sp . 1 . Fermentation, isolation and characterization; Ozasa T et al.; New antibiotics designated as thiazocins A and B were isolated from the culture broth of Actinosynnema sp . C-304 . Thiazocins A and B exhibited inhibitory activities against an aldose reductase from human placenta.

J Dairy Sci, 1991 Jul, 74(7), 2256 - 67
Effect of grain level and protein source on ruminal fermentation, degradability, and digestion in milking cows fed silage; Petit HV et al.; Five primiparous Holstein cows (483 kg BW) of low productivity were used in a 4 x 5 incomplete Latin square design to study the effects of feeding two levels of grain containing soybean meal and one level of grain containing fish meal on feed intake, milk production, digestibility, and rumen fermentation . Animals all were fed alfalfa silage for ad libitum intake . Collection of data was between wk 11 and 24 of lactation . The four treatments were an all silage diet (control), silage and medium concentrate fed at 1.8% BW containing soybean meal, and silage and low concentrate fed at 1.3% BW containing either soybean meal or fish meal . Treatments other than control were designed to give similar CP intake from the concentrate, which was based on high moisture corn and cob meal . Milk production and composition were similar among treatments except for fat percentage, which was significantly lower for low grain soybean meal . Intake of DM was higher on medium grain soybean meal compared with the other treatments . Average BW and change in BW (.11 kg/d) were not affected by treatments . Digestibility of DM was higher for cows fed grain (68 to 73%) than for those fed the control diet (60%) . Generally, feeding concentrate at 1.3 or 1.8% BW and supplementing with soybean meal or fish meal resulted in pH and concentrations of NH3 N and VFA similar to those observed on the all silage diet . Feeding concentrate at 1.3 or 1.8% BW and supplying fish meal or soybean meal did not change feed utilization enough to increase milk production in low producing cows compared with an all silage diet.

J Dairy Sci, 1991 Jul, 74(7), 2186 - 99
Immunoreactive fraction 1 leaf protein and dry matter content during wilting and ensiling of ryegrass and alfalfa; Mangan JL et al.; In four experiments with ryegrass and alfalfa, cut herbage was wilted in the field and silage made in 1- or 200-L silos . Direct-cut (mean DM, 20.3%), low wilt (mean DM, 26.0%), medium wilt (mean DM, 36.2%) and high wilt (mean DM, 47.7%) herbages were used . Fraction 1, the most abundant leaf protein, was measured by crossed immunoelectrophoresis using rabbit anti-Fraction 1 serum . In two ryegrass and one alfalfa experiments in which weather conditions allowed rapid drying to high wilt herbage in 24 h, there was no significant loss of Fraction 1 protein . In the second alfalfa experiment, in which wilting was prolonged to 3 d by adverse weather, there was a 70% loss of Fraction 1 . Ensiling proceeded normally in the four experiments, with rapid fall in pH and production of VFA, lactate, and NPN; the extent and rates of production were inversely related to DM content . In alfalfa and ryegrass, pH fell below the isoelectric point of Fraction 1 within 8 d . In each ryegrass experiment, a high proportion (58 to 100%) of Fraction 1 in medium and high wilt silages survived fermentation for 28 and 68 d, with lesser amounts in other silages . With alfalfa, however, almost all Fraction 1 protein was degraded at all DM concentrations during fermentation . Fiber-associated protein increased markedly with increases in DM during wilting, and these differences were present in the mature silage of both ryegrass and alfalfa . Digestibility studies with fistulated sheep showed that appreciable amounts of immunoreactive Fraction 1 protein in ryegrass silages were undegraded in the rumen.

Am J Vet Res, 1991 Jul, 52(7), 1065 - 8
Characterization of eugonic fermenters group EF-4 by polyacrylamide gel electrophoresis and protein immunoblot analysis; Hanner TL et al.; Whole-cell lysates and proteinase K-extracted lipopolysaccharide (LPS) of 19 strains of the group eugonic fermenter-4 (EF-4) were analyzed by electrophoresis and protein immunoblotting . These strains were isolated from dog- and cat-bite abscesses in human beings, ferret and human gastric lesions, and cat-lung infections . These strains represent 2 biovar groupings; EF-4a biovars ferment glucose and possess arginine dihydrolase activity, whereas EF-4b biovars do not . Electrophoresis of whole-cell lysates could distinguish between these biovars groups . Electrophoresis of LPS extracts revealed that all strains of EF-4 possess smooth chemotypes . Two strains of EF-4a reacted weekly in protein immunoblots and revealed distinct LPS profiles . These studies suggests that subgroups of EF-4 biovars may exist.

J Antibiot (Tokyo), 1991 Jul, 44(7), 741 - 55
Fluvirucins A1, A2, B1, B2, B3, B4 and B5, new antibiotics active against influenza A virus . II . Structure determination; Naruse N et al.; A series of structurally related antiviral antibiotics, fluvirucins A1, A2, B1, B2, B3, B4 and B5 have been isolated from the fermentation broths of five unidentified actinomycete isolates . Based on spectroscopic analysis, partial degradation experiments and 13C-enriched acetic acid-fed biosynthetic studies, their structures were elucidated to be 2.6,10-trialkyl-3(or 9)-aminoglycosyl-13-tridecanelactams.

Genetics, 1991 Jul, 128(3), 521 - 7
Saccharomyces cerevisiae null mutants in glucose phosphorylation: metabolism and invertase expression; Walsh RB et al.; A congenic series of Saccharomyces cerevisiae strains has been constructed which carry, in all combinations, null mutations in the three genes for glucose phosphorylation: HXK1, HXK2 and GLK1, coding hexokinase 1 (also called PI or A), hexokinase 2 (PII or B), and glucokinase, respectively: i.e., eight strains, all of which grow on glucose except for the triple mutant . All or several of the strains were characterized in their steady state batch growth with 0.2% or 2% glucose, in aerobic as well as respiration-inhibited conditions, with respect to growth rate, yield, and ethanol formation . Glucose flux values were generally similar for different strains and conditions, provided they contained either hexokinase 1 or hexokinase 2 . And their aerobic growth, as known for wild type, was largely fermentative with ca . 1.5 mol ethanol made per mol glucose used . The strain lacking both hexokinases and containing glucokinase was an exception in having reduced flux, a result fitting with its maximal rate of glucose phosphorylation in vitro . Aerobic growth of even the latter strain was largely fermentative (ca . 1 mol ethanol per mol glucose) . Invertase expression was determined for a variety of media . All strains with HXK2 showed repression in growth on glucose and the others did not . Derepression in the wild-type strain occurred at ca . 1 mM glucose . The metabolic data do not support- or disprove-a model with HXK2 having only a secondary role in catabolite repression related to more rapid metabolism.

Anat Rec, 1991 Jul, 230(3), 417 - 24
Equine myenteric plexus with special reference to the pelvic flexure pacemaker; Burns GA et al.; Sellers et al . (1979, Am . J . Phys., 237: E457-E464) proposed a pelvic flexure pacemaker mechanism to account for the bidirectional contraction waves needed to both retain ingesta within the right ventral colon for cellulose digestion and terminal fermentation and to transport the digesta distad once the process has been completed . To corroborate the presence of a pelvic flexure pacemaker, we prepared whole mount samples of the tunica muscularis from 23 horses at ten sites along the large colon, cecum and jejunum . Following smooth muscle enzymatic digestion, somata of the myenteric plexus were stained with an RNA-specific agent, Cuprolinic blue . These somata were quantified at each site to establish any regional variations in neuronal density . Results indicated an increased neuronal density at the level of the pelvic flexure, especially in the region of the left dorsal colon . The increased neuronal density at the left dorsal colon compared to the other sampling sites was statistically significant (Wilcoxon signed rank test, P less than .01 at each sampling site) . There was remarkable size variation (from 10-60 microns) among neurons at the individual sampling sites . However, no statistically significant size discrepancy existed between sampling sites (Friedman's rank test, P = .10) . The 23 horses ranged from 6 months to 15 years of age . No age-related differences in neuronal density was discovered (Kruskal-Wallis ANOVA test, P greater than .05) . Neuronal densities did not vary on the basis of sex (Wilcoxon signed pairs test, P greater than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Proc Natl Sci Counc Repub China B, 1991 Jul, 15(3), 131 - 9
Production of beta-fructofuranosidase with transfructosylating activity for fructooligosaccharides synthesis by Aspergillus japonicus NTU-1249; Su YC et al.; Microbial beta-fructofuranosidases with transfructosylating activity can catalyze the transfructosylation of sucrose and synthesize fructooligosaccharides . Aspergillus japonicus NTU-1249 isolated from natural habitat was found to produce a significant amount of beta-fructofuranosidase with high transfructosylating activity and to have the potential for industrial production of fructooligosaccharides . In order to improve it's enzyme productivity, the medium composition and the cultivation conditions for A . japonicus NTU-1249 were studied . A . japonicus NTU-1249 can produce 83.5 units of transfructosylating activity per ml broth when cultivated in a shaking flask at 28 degrees C for 72 hours with a modified medium containing 80 g/l sucrose, 15 g/l soybean flour, 5 g/l yeast extract and 5 g/l NaCl at an initial pH of 6.0 . The enzyme productivity was also optimized by submerged cultivation in a 5-litre jar fermentor with aeration at 1.5 vvm and agitation at 500 rpm . Under these operating conditions, the productivity of transfructosylating activity increased to 185.6 U/ml . Furthermore, the transfructosylating activity was improved to 256.1 U/ml in 1,000-litre pilot-scale fermentor . Enzymatic synthesis of fructooligosaccharides by beta-fructofuranosidase from A . japonicus NTU-1249 was performed in batch type by adding 5.6 units of transfructosylating activity per gram of sucrose to a 50% (w/v) sucrose solution at pH 5.0 and 50 degrees C . The yield of fructooligosaccharides was about 60% after reaction for 24 hours, and the syrup produced contained 29.8% (w/v) fructooligosaccharides, 15.2% (w/v) glucose and 5.0% (w/v) sucrose.

Nutr Rev, 1991 Jul, 49(7), 195 - 203
Soluble fiber polysaccharides: effects on plasma cholesterol and colonic fermentation; Topping DL; Many soluble-fiber polysaccharides, used as stabilizers and thickeners by the food industry, lower plasma cholesterol and slow small intestinal transit and nutrient absorption . Although nondigestible by human enzymes, these polysaccharides are fermented by the large-bowel microflora, yielding short-chain fatty acids that are absorbed and contribute to energy . The caloric yield from fiber polysaccharides needs to be quantified . Short-chain fatty acid production from soluble fibers is modified by the presence of insoluble fibers but, in total, is probably less than from other carbohydrates, e.g., resistant starch . Short-chain fatty acids do not seem to mediate effects of fiber on plasma cholesterol, but in the large bowel they exert the trophic and antineoplastic effects of dietary fiber . The mechanism for cholesterol reduction by soluble fibers relates to enhanced steroid excretion and altered fat absorption and may be a function of the viscosity of these fibers in solution . The relationships between the chemical structure of soluble polysaccharides and their documented physiologic effects are not yet clear . By using polysaccharides of defined structure and properties, it should be possible to identify those characteristics that predict physiologic actions.

J Dairy Sci, 1991 Jul, 74(7), 2220 - 32
Effects of calcium salts of fatty acids and proportion of forage in diet on ruminal fermentation and nutrient flow to duodenum of cows; Klusmeyer TH et al.; Four Holstein cows fitted with ruminal and duodenal cannulas were used in a 4 x 4 Latin square to investigate the effects of calcium salts of long-chain fatty acids (fat) and proportion of forage in diet on ruminal fermentation, flow of nutrients to the small intestine, and animal performance . Treatments, arranged in a 2 x 2 (fat x forage) factorial, were 1) low (50%) forage, no fat; 2) low forage, fat; 3) high (67%) forage, no fat; and 4) high forage, fat . Feeding fat decreased OM intake and OM truly digested in the rumen . Feeding high forage diets decreased intakes of OM and starch and increased intakes of ADF and NDF . Ruminal pH and ratio of acetate to propionate were increased with high forage diets compared with low forage diets . Feeding fat and different amounts of forage to cows did not alter the flows of NAN and microbial N to the duodenum or efficiency of microbial growth . Production of milk and 4% FCM and percentage of fat in milk were increased by feeding fat . Feeding high forage diets decreased milk production, increased percentage of fat in milk, increased the yield of fat, and caused no change in 4% FCM production . The percentage of protein in milk was decreased by feeding high forage diets and fat, but yield of milk protein was decreased only by feeding high forage diets to cows.

J Dairy Sci, 1991 Jul, 74(7), 2206 - 19
Effects of calcium salts of fatty acids and protein source on ruminal fermentation and nutrient flow to duodenum of cows; Klusmeyer TH et al.; Four Holstein cows fitted with ruminal and duodenal cannulas were used in a 4 x 4 Latin square to investigate the effects of calcium salts of long-chain fatty acids (fat) and source of protein (fish meal or soybean meal) on ruminal fermentation, flow of nutrients to the small intestine, and animal performance . Cows were fed for ad libitum intake a diet of 30% alfalfa haylage, 20% corn silage, and 50% concentrate on a DM basis . Treatments, arranged in a 2 x 2 (fat x protein) factorial, were 1) soybean meal, no fat; 2) soybean meal, fat; 3) fish meal, no fat; and 4) fish meal, fat . Intake of DM was not affected by fat or protein source, but feeding fat decreased the amount of OM truly digested in the rumen . Starch intake was decreased, but flow of starch to the duodenum was not altered by feeding fat . Nonammonia N and microbial N flows to the duodenum were not affected by treatment comparisons . However, efficiency of microbial growth was increased by feeding fat, but not by source of protein . Passage of amino acids to the duodenum was not affected by source of protein, probably because fish meal contributed only 17% of the total dietary CP, and microbial N constituted about 50% of the NAN passing to the duodenum; this had an equalizing effect on the pattern and quantity of amino acids that passed to the duodenum . Feeding fat or different sources of protein did not alter milk production . Milk fat percentage was increased, and protein percentage was decreased when fat was fed, but yields of milk fat and protein were not different.

Vet Clin North Am Food Anim Pract, 1991 Jul, 7(2), 327 - 40
Carbohydrate nutrition; Allen MS; An understanding of carbohydrate nutrition is essential to optimize production of dairy cattle . Two rations, both of which appear to be balanced, may have dramatically different results when fed to high-producing dairy cattle . Carbohydrates directly affect microbial protein production and therefore protein nutrition of dairy cattle . Energy intake can be maximized by considering the amount and type of carbohydrate in the ration: 1 . The fiber level of the ration should be evaluated . NDF levels should be between 25 and 30% for high-producing cows in early lactation . Within this range, less fiber is required with adequate forage particle length and high frequency of grain feeding, and when buffers are fed and slowly fermented NSC sources are included in the ratio . For mid- and late-lactation cows, fiber levels are higher, ranging between 30 and 36% NDF depending upon the energy required to support milk production and restoration of body condition . 2 . Provide adequate effective fiber . There should be some forage particles 1.5 in long in the ration . Limit most high-fiber byproducts to 25% of fiber requirements . 3 . Feed highly digestible fiber sources . Differences in fiber digestibility of 30% will result in over 4 Mcal of NEL per day with 15 lb NDF intake . In addition, highly digestible fiber has less gut fill effect, possibly increasing dry matter intake . 4 . Consider site of starch digestion . Slowly degraded starch sources such as sorghum may require steam flaking to increase ruminal fermentation . Other situations may require the addition of a slowly degraded starch source . 5 . Increase frequency of concentrate feeding . Feed grain at least four times per day or include in a total mixed ration . 6 . Include buffers . Under some situations (corn silage, early lactation) buffers allow more grain to be fed . 7 . Add fat . Fat supplementation to milking cows has become a common practice in high-producing herds . Fat has about three times the energy of cracked corn and is often used to replace a portion of the grain to increase the energy density of the ration . It is important to realize that fat can cost up to two to three times more per megacalorie of energy than grain . Before fat is added to the ration, less expensive ways to increase energy density (listed previously) should be thoroughly explored.

J Anim Sci, 1991 Jul, 69(7), 3027 - 38
Pregnancy and lactation in beef heifers grazing tallgrass prairie in the winter: influence on intake, forage utilization, and grazing behavior; Vanzant ES et al.; Six ruminally and eight bifistulated (ruminal and esophageal) Hereford x Angus heifers were used to determine effects of pregnancy and early lactation on forage intake and utilization under grazing conditions . Three ruminally and three bifistulated heifers were bred (pregnant/lactating; P/L; average calving date was February 11, 1989); remaining heifers served as controls (C) . The experiment consisted of three periods (P1 = average of 55 d before parturition; P2 = average of 12 d before parturition; P3 = average of 26 d after parturition) . All heifers grazed the same 24-ha Flint Hills range pasture . Dehydrated alfalfa pellets were supplemented at .5% BW/heifer daily prepartum and at .8% BW/heifer daily postpartum . Treatment x period interactions were noted (P less than .10) for forage OM intake, ruminal capacity, indigestible ADF (IADF) fill, and grazing time but not for OM digestibility or IADF passage rate (P greater than .10) . In P1 and P3, P/L heifers had greater (P less than .10) forage OM intake than C heifers, whereas no differences were noted (P greater than .10) in P2 . Pregnant/lactating heifers spent less time (P less than .10) grazing than did controls in P2 and more time (P less than .10) than controls in P3 . Ruminal IADF fill and ruminal capacity, as measured by water fill, tended (P = .14 and .16, respectively) to differ between the two groups in P2 . Digestibility of OM was unaffected (P greater than .10) by physiological status, whereas IADF passage rate was greater (P less than .10) in P/L heifers . Only minor differences were noted for the chemical composition of diets selected by the two groups . Ruminal fermentation patterns shifted only slightly; the largest effects were in P3, when P/L heifers had greater (P less than .10) propionate and less (P less than .10) acetate (mol/100 mol) than C heifers . In summary, during the period just before parturition, differences in forage OM intake between P/L and C heifers disappeared, and ruminal fill and capacity tended to be lower for P/L heifers . Intake was 16% greater for P/L than for C heifers during the early postpartum period . Organic matter digestibility was not influenced by physiological status, even though IADF passage rates were greater for P/L heifers.

J Antibiot (Tokyo), 1991 Jul, 44(7), 723 - 8
A new antitumor substance BE-13793C, produced by a streptomycete . Taxonomy, fermentation, isolation, structure determination and biological activity; Kojiri K et al.; A new antitumor substance, BE-13793C, which has topoisomerase inhibitory activity was isolated from the culture broth of a strain of actinomycetes . The producing strain, BA13793, isolated from a soil sample collected in Seto, Aichi Prefecture, Japan, has a resemblance to Streptoverticillium mobaraense . The active principle was extracted from the mycelium of strain BA13793 with methanol and purified by Sephadex LH-20 column chromatography . BE-13793C showed strong inhibitory activity against topoisomerases I and II and inhibited the growth of doxorubicin-resistant or vincristine-resistant P388 murine leukemia cell lines, as well as their parent P388 cell line.

Biotechnol Prog, 1991 Jul-Aug, 7(4), 299 - 304
Flow cytometry and cell cycle kinetics in continuous and fed-batch fermentations of budding yeast; Alberghina L et al.; Cell size distributions, obtained either as protein distribution by flow cytometry or as cell volume distribution by a Coulter counter, give relevant information about the growth conditions of populations of budding yeast Saccharomyces cerevisiae . We have previously found a good correlation between these distributions and the growth rate in continuous cultures (Ranzi et al., Biotechnol . Bioeng . 1986, 28, 185-190) . We now present determinations of the protein distributions and cell volume distributions during different fed-batch fermentations performed with a simple on/off controller . Since during the fed-batch fermentation a true steady state is not obtained, the distributions continuously change with time, but nevertheless we observed a good correlation between the average of both distributions and the actual growth rate . The behavior of the cell size distributions can be interpreted on the basis of a two-threshold cell cycle model in which both the critical protein content at budding (Ps) and the critical protein content for cell division (Pm) are differently modulated by the growth rate . Additional findings will be presented showing that this model can be used to successfully explain the insurgence and the maintenance of oscillatory states in continuous cultures.

Int J Cancer, 1991 Jun 19, 48(4), 540 - 9
Intake of foods and nutrients and cancer of the exocrine pancreas: a population-based case-control study in The Netherlands; Bueno de Mesquita HB et al.; During 1984-88 a population-based case-control study was carried out in the Netherlands in collaboration with the International Agency for Research on Cancer in order to investigate the role of diet in exocrine pancreatic carcinoma . A semi-quantitative food-frequency questionnaire was used to comprehensively assess usual diet about 1 year prior to diagnosis of 164 cases or interview of 480 controls . More than half of the cases were directly interviewed . After controlling for age, gender, response status, life-time cigarette consumption and dietary intake of total energy, monotonic, significantly inverse dose-response effects with estimates of daily consumption of vegetables were found . The significant inverse effect of total cooked vegetables was primarily concentrated in cruciferous vegetables . Consumption of fresh vegetables was also significantly and inversely related to risk . A monotonic, positive dose-response gradient was seen for the consumption of eggs, while consumption of fish was significantly related to risk as well . Among direct respondents, significantly inverse relationships were found for the consumption of legumes, tomatoes, cheese and fermented milk products . Inverse associations with consumption of (subgroups of) fruits were observed in women only . The monotonic, significantly inverse relationship for consumption of low-fibre vegetables and the somewhat weaker, inverse association for high-fibre vegetables in directly interviewed subjects only, may point to protective agents other than vegetable fibre . Although intake of dietary fibre and beta-carotene were both inversely related to risk, simultaneous estimation suggested that beta-carotene or other as yet unknown correlated constituents, rather than dietary fibre, might explain the inverse relationships . A significant protective effect of vitamin C was demonstrated in women but not in men . Our study suggests that, independent of smoking and dietary intake of total energy, low consumption of specific vegetables and possibly fermented milk products and high consumption of eggs and fish may have influenced the development of exocrine pancreatic cancer.

Biochemistry, 1991 Jun 11, 30(23), 5789 - 96
Biosynthesis of the immunosuppressant immunomycin: the enzymology of pipecolate incorporation; Nielsen JB et al.; Immunomycin, an immunosuppressant closely related to FK 506, contains a pipecolate residue in amide linkage with an acyl group in its polyketide backbone . An enzyme activating L-pipecolic acid has been isolated from Streptomyces hygroscopicus var . ascomyceticus, which produces immunomycin . Purification results in a monomer of 170 kDa exhibiting N-terminal heterogeneity, apparently arising from proteolysis of a single species . It is a dimer under native conditions . The reaction appears to use an aminoacyl adenylate as an intermediate in the activating reaction, as do most activating enzymes involved in nonribosomal peptide synthesis . A range of pipecolate and proline analogues act as substrates in the pyrophosphate-ATP exchange resulting from the adenylation reaction . Several analogues are inhibitors of the subsequent thioesterification of the enzyme . Antibody raised to the purified enzyme was used to follow antigen during the course of fermentation . Maximal levels of antigen are found when synthesis of immunomycin is maximal . Ten of twelve immunomycin nonproducing mutants lack detectable pipecolate-activating enzyme in Western blots . From the enzymatic characteristics, substrate specificity, and immunological properties, we propose that we have isolated the enzyme responsible for activating pipecolic acid for immunomycin biosynthesis.

Clin Lab Manage Rev, 1991 Jul-Aug, 5(4), 221 - 3, 226-9, 232-3
The new health-care quality: value, outcomes, and continuous improvement; O'Connor SJ et al.; No longer convinced that their viewpoint on quality is the only one, different stakeholders in the health-care arena are sharing perspectives to piece together the quality picture . Although still preoccupied with the cost of health care, purchasers are concerned about value--efficiency, appropriateness, and effectiveness--as well as price . Faced with evidence of medically unnecessary procedures and unexamined medical theory, practitioners are searching for appropriateness guidelines, useful outcome measures, and methods to elicit informed patient preferences about elective surgeries . Underlying this search for reliable indicators of quality--now expanded to include patient satisfaction--is a new interest in the Japanese notion of "Kaizen" or continuous quality improvement . The end product of this ferment may determine whether good medicine drives out the bad--or vice versa.

J Antibiot (Tokyo), 1991 Jun, 44(6), 589 - 99
TAN-931, a novel nonsteroidal aromatase inhibitor produced by Penicillium funiculosum No . 8974 . I . Taxonomy, fermentation, isolation,characterization and biological activities; Ishii T et al.; A novel nonsteroidal aromatase inhibitor, TAN-931, was isolated from the culture filtrate of a soil isolate fungus, No . 8974 . The strain was identified as Penicillium funiculosum No . 8974 . TAN-931 inhibited human placental and rat ovarian aromatase activity, and the IC50 value was 17.2 and 162 microM, respectively . The inhibition of human placental aromatase was uncompetitive with respect to androstenedione conversion with a Ki value of 40 microM . When TAN-931 was subcutaneously administered at doses of 25, 50 and 100 mg/kg (once/day, x4) to 20-day-old female Sprague-Dawley rats treated with gonadotropin, the plasma estradiol-17 beta level and the weight of ovaries and uterus were markedly reduced in a dose-dependent manner . The in vivo inhibitory activity of TAN-931 was more potent than that of 4-hydroxyandrostenedione . Consecutive administration of TAN-931 (100 mg/kg, sc, twice/day, x 7) to 9-week-old male Sprague-Dawley rats did not induce any adrenal hypertrophy even though administration of aminoglutethimide caused 2-fold enlargement of the adrenal under the same conditions . Specific binding of TAN-931 to the estrogen receptor from a human breast cancer cell line, MCF-7, was not detected.

J Antibiot (Tokyo), 1991 Jun, 44(6), 582 - 8
Cyclothiazomycin, a novel polythiazole-containing peptide with renin inhibitory activity . Taxonomy, fermentation, isolation and physico-chemical characterization; Aoki M et al.; Cyclothiazomycin is a novel renin inhibitor produced by Streptomyces sp . NR0516 . It was isolated from fermentation broth by extraction with butyl alcohol, QAE-Toyopearl column chromatography and preparative HPLC . Cyclothiazomycin, which was determined to be a unique polythiazole-containing bicyclic peptide, exhibited inhibitory activity against human plasma renin with IC50 being 1.7 microM.

Gastroenterol Clin North Am, 1991 Jun, 20(2), 313 - 24
Diet and the irritable bowel syndrome; Friedman G; Food intake plays a key role in triggering or perpetuating symptoms in patients with IBS . Evaluation of the impact of diet in the individual patient requires a precise dietary history and a 7-day prospective dietary analysis, which should include the quality and quantity of food consumed, chronologic sequence and nature of symptoms, and the frequency and consistency of bowel movements . The caloric density of the meal, total fat intake, the quantity and quality of lactose-containing foods, sorbitol, fructose, and the nature and quantity of soluble and insoluble fiber intake must be noted . Patients with reflux esophageal symptoms should eliminate foods that decrease LES pressure, such as chocolate, peppermint, alcohol, and coffee . Direct esophageal mucosal irritants such as tomatoes, citrus juices, sharp condiments, and alcohol should be limited . Gastric emptying is slowed with the ingestion of fats and soluble fiber . Small bowel motility is slowed by soluble fiber and fatty foods . Gaseous syndromes may be reduced by avoidance of smoking, chewing gum, excessive liquid intake, and carbonated drinks . The reduced intake of large amounts of lactose-containing foods, sorbitol, and fructose may limit postprandial bloating . Flatus production can be lowered by reducing fermentable carbohydrates such as beans, cabbage, lentils, brussel sprouts, and legumes . Soluble and insoluble fiber ingestion will reduce sigmoidal intraluminal pressures and overcome spastic constipation when given in progressive graded doses . Effective dietary manipulations remain a key factor in reducing symptoms in IBS.

Cancer Res, 1991 Jun 1, 51(11), 2940 - 2
Inhibition of benzo(a)pyrene-induced mouse forestomach neoplasia by dietary soy sauce; Benjamin H et al.; We show that Japanese-style fermented soy sauce (shoyu) contains anticarcinogenic activity . Female ICR mice were fed a semipurified diet containing soy sauce (0-30%) . Two weeks later a regimen consisting of 4 doses of benzo(a)pyrene (1 dose/week p.o . for 4 weeks) was begun to initiate forestomach neoplasia . Twenty-three weeks after the first intubation the animals were sacrificed, and forestomach neoplasms were counted and histologically confirmed . Soy sauce produced a significant dose-dependent reduction in forestomach neoplasms, which appeared to be maximal when soy sauce constituted 20% of the diet . Exposure to nitrite (0-500 ppm through drinking water) neither enhanced nor diminished the anticarcinogenic effect of the dietary soy sauce . Soy sauce was found to contain antioxidant activity which may be related to the observed anticarcinogenic effect . Contrary to expectations, mouse forestomach ornithine decarboxylase activity was induced by soy sauce . This appeared to be due at least in part to the relatively high sodium chloride content of soy sauce.

Arch Tierernahr, 1991 Jun, 41(5), 521 - 6
Preliminary observations on the relationship between gas production and microbial protein synthesis in vitro; Krishnamoorthy U et al.; The relationship between gas production and microbial protein synthesis was studied in vitro using the method of MENKE et al . (1979) . 150 mg starch or cellulose or a mixture of 10% glucose, 40% starch and 50% cellulose was used as the carbohydrate source . The microbial protein synthesis and gas production occurring during 2 hrs after the 5th, 10th, and 23rd hr of incubation were studied . Total and net microbial synthesis were estimated using 32P as a microbial marker and by the net disappearance of NH3-N respectively . The data indicate that the type of carbohydrate and the rate of carbohydrate fermentation influence microbial protein synthesis per unit volume of gas produced . However, the relationship between total synthesis and cumulative gas production (up to 8 hrs incubation) with carbohydrate mixture as the substrate was linear . With reference to these observations, the possibilities and difficulties in using cumulative gas production as an index of microbial growth potential of the feedstuffs are discussed.

J Gen Microbiol, 1991 Jun, 137 ( Pt 6), 1409 - 17
Influence of CO2 and low concentrations of O2 on fermentative metabolism of the rumen ciliate Dasytricha ruminantium; Ellis JE et al.; The effects of ruminal concentrations of CO2 and O2 on glucose-stimulated and endogenous fermentation of the rumen isotrichid ciliate Dasytricha ruminantium were investigated . Principal metabolic products were lactic, butyric and acetic acids, H2 and CO2 . Traces of propionic acid were also detected; formic acid present in the incubation supernatants was found to be a fermentation product of the bacteria closely associated with this rumen ciliate . 13C NMR spectroscopy revealed alanine as a minor product of glucose fermentation by D . ruminantium . Glucose uptake and metabolite formation rates were influenced by the headspace gas composition during the protozoal incubations . The uptake of exogenously supplied D-glucose was most rapid in the presence of O2 concentrations typical of those detected in situ (i.e . 1-3 microM) . A typical ruminal gas composition (high CO2, low O2) led to increased butyrate and acetate formation compared to results obtained using O2-free N2 . At a partial pressure of 66 kPa CO2 in N2, increased cytosolic flux to butyrate was observed . At low O2 concentrations (1-3 microM dissolved in the protozoal suspension) in the absence of CO2, increased acetate and CO2 formation were observed and D . ruminantium utilized lactate in the absence of extracellular glucose . The presence of both O2 and CO2 in the incubation headspaces resulted in partial inhibition of H2 production by D . ruminantium . Results suggest that at the O2 and CO2 concentrations that prevail in situ, the contribution made by D . ruminantium to the formation of ruminal volatile fatty acids is greater than previously reported, as earlier measurements were made under anaerobic conditions.

J Gen Microbiol, 1991 Jun, 137 ( Pt 6), 1401 - 8
Comparison of growth characteristics of anaerobic fungi isolated from ruminant and non-ruminant herbivores during cultivation in a defined medium; Teunissen MJ et al.; Anaerobic fungi were isolated from rumen fluid of a domestic sheep (Ovis aries; a ruminant) and from faeces of five non-ruminants: African elephant (Loxodonta africana), black rhinoceros (Diceros bicornis), Indian rhinoceros (Rhinoceros unicornis), Indian elephant (Elephas maximus) and mara (Dolichotis patagonum) . The anaerobic fungus isolated from the sheep was a Neocallimastix species and the isolates from non-ruminants were all species similar to Piromyces spp . A defined medium is described which supported growth of all the isolates, and was used to examine growth characteristics of the different strains . For each fungus the lipid phosphate content was determined after growth on cellobiose and the resulting values were used to estimate fungal biomass after growth on solid substrates . The ability of isolates from ruminants and non-ruminants to digest both wheat straw and cellulose was comparable . More than 90% and 60%, respectively, of filter paper cellulose and wheat straw were digested by most strains within 60-78 h . Growth of two fungi, isolated from rumen fluid of a sheep (Neocallimastix strain N1) and from faeces of an Indian rhinoceros (Piromyces strain R1), on cellobiose was studied in detail . Fungal growth yields on cellobiose were 64.1 g (mol substrate)-1 for N1 and 34.2 g mol-1 for R1 . The major fermentation products of both strains were formate, lactate, acetate, ethanol and hydrogen.

Afr J Med Med Sci, 1991 Jun, 20(2), 101 - 5
Breath hydrogen excretion or plasma acetate levels during the lactulose tolerance test?
Akanji AO, Hockaday TD.
Since both acetate and hydrogen are produced by colonic bacterial fermentation, the clinical utility of the measurement of either parameter in nine subjects for the lactulose tolerance test was tested . The fasting plasma acetate concentration (mean +/- s.d., mmol/l) of 0.11 +/- 0.06 increased to peak levels between 150 min (0.23 +/- 0.12) and 180 min (0.23 +/- 0.09), both P less than 0.01, after ingesting 20 g lactulose . In one subject with previous gastrectomy and intestinal hurry, the peak was at 30 min . Mean post-lactulose acetate levels (0.21 +/- 0.09) were higher than fasting levels (P less than 0.03) . Breath hydrogen excretion exhibited a similar trend . Indeed, a significant correlation (rs 0.39, P less than 0.01) was demonstrated between the acetate and hydrogen values . It is therefore concluded that patients for the lactulose breath test show fairly similar changes in plasma acetate and breath hydrogen excretion after lactulose ingestion . Either measurement could thus be used in assessing colonic fermentation in humans.

J Antibiot (Tokyo), 1991 Jun, 44(6), 613 - 25
Novel and potent gastrin and brain cholecystokinin antagonists from Streptomyces olivaceus . Taxonomy, fermentation, isolation, chemical conversions, and physico-chemical and biochemical properties; Lam YK et al.; The discovery and physico-chemical characterization of three novel and minor virginiamycin M1 analogs as potent gastrin antagonists from a culture of a strain of Streptomyces olivaceus are described . These analogs are L-156,586, L-156,587 and L-156,588 . They are, respectively, 15-dihydro-13,14-anhydro-, 13,14-anhydro- and 13-desoxy-analogs of virginiamycin M1 . We also chemically converted virginiamycin M1 (via L-156,587) to L-156,586 and its unnatural epimer, L-156,906 . These analogs are competitive and selective antagonists of gastrin and brain cholecystokinin binding at nanomolar concentrations . These are the most potent gastrin/brain cholecystokinin antagonists from natural products . The same compounds showed poor Gram-positive antibiotic activity versus virginiamycin M1 . Structurally related Gram-positive antibiotics, griseoviridin and madumycin I, were inactive in gastrin and brain cholecystokinin binding at up to 100 microM.

Microbiol Rev, 1991 Jun, 55(2), 259 - 87
Dissimilatory Fe(III) and Mn(IV) reduction; Lovley DR; The oxidation of organic matter coupled to the reduction of Fe(III) or Mn(IV) is one of the most important biogeochemical reactions in aquatic sediments, soils, and groundwater . This process, which may have been the first globally significant mechanism for the oxidation of organic matter to carbon dioxide, plays an important role in the oxidation of natural and contaminant organic compounds in a variety of environments and contributes to other phenomena of widespread significance such as the release of metals and nutrients into water supplies, the magnetization of sediments, and the corrosion of metal . Until recently, much of the Fe(III) and Mn(IV) reduction in sedimentary environments was considered to be the result of nonenzymatic processes . However, microorganisms which can effectively couple the oxidation of organic compounds to the reduction of Fe(III) or Mn(IV) have recently been discovered . With Fe(III) or Mn(IV) as the sole electron acceptor, these organisms can completely oxidize fatty acids, hydrogen, or a variety of monoaromatic compounds . This metabolism provides energy to support growth . Sugars and amino acids can be completely oxidized by the cooperative activity of fermentative microorganisms and hydrogen- and fatty-acid-oxidizing Fe(III) and Mn(IV) reducers . This provides a microbial mechanism for the oxidation of the complex assemblage of sedimentary organic matter in Fe(III)- or Mn(IV)-reducing environments . The available evidence indicates that this enzymatic reduction of Fe(III) or Mn(IV) accounts for most of the oxidation of organic matter coupled to reduction of Fe(III) and Mn(IV) in sedimentary environments . Little is known about the diversity and ecology of the microorganisms responsible for Fe(III) and Mn(IV) reduction, and only preliminary studies have been conducted on the physiology and biochemistry of this process.

In Vitro Cell Dev Biol, 1991 Jun, 27A(6), 509 - 13
Elimination of mycoplasmas from cell cultures by a novel soft agar technique; Kotani H et al.; Mycoplasmal infection of cell cultures remains a significant threat to diagnostic and research procedures . In certain defined situations, curing of mycoplasmal infected cultures is a reasonable exercise . Four methods of curing were compared: treatment with BM-cycline, 5 bromouracil, use of specific antisera and treatment of infected cells suspended in soft agar with antibiotics . Antisera treatments were of low efficiency of curing: 50% . None of nine infected cell lines treated with 5-bromouracil were consistently cured of mycoplasmas . The use of BM-cycline was effective for some, but not all lines and required long periods of treatment, 12-21 days . 35 naturally or deliberately infected cultures were treated in soft agar a total of 119 times . This procedure which consisted of suspending infected cultures in soft agar containing appropriate antibiotics resulted in successful mycoplasmal elimination 118/119 times . This soft agar technique took 1-3 days . In separate studies, it was shown that certain Mycoplasma fermentans strains were resisted to this and other curing methods . This may be due to their intracellular location . Such strains may be more amenable to antibiotics that penetrate mammalian cells . It is concluded that the soft agar technique is a rapid, efficient and reliable method to eliminate cell culture mycoplasmas.

J Trop Pediatr, 1991 Jun, 37(3), 111 - 5
Infant feeding and growth in rural Ghana: is the use of the traditional fermented porridge a case for early supplementation?
Armar-Klemesu MA, Wheeler EF, Brakohiapa LA, Yamamoto S.
Thirty infants were studied longitudinally for 6 months . Breast milk and intakes of supplements were measured at the first and third months post-partum . Mode of feeding, morbidity, and weights were recorded monthly . Variations in growth were found to be related to levels of breast milk intakes, and timely and effective supplementation with the traditional weaning porridge prepared from fermented maize dough . No diarrhoeal incidence was recorded before 3 months . It is suggested that coupled with true demand breast feeding, the traditional weaning porridge could adequately support growth if introduced on time, even when breast milk intakes are less than optimal.

Appl Environ Microbiol, 1991 Jun, 57(6), 1701 - 6
Effects of increased transaldolase activity on D-xylulose and D-glucose metabolism in Saccharomyces cerevisiae cell extracts; Senac T et al.; In vitro metabolism of D-xylulose and D-glucose in extracts obtained from D-glucose- and D-xylulose-fermenting Saccharomyces cerevisiae cells was investigated with 10- and 100-fold-increased activity of the enzyme transaldolase (EC 2.2.1.2) . The rate of sugar consumption was the same in most cases, whereas the rate of ethanol formation decreased with increased levels of transaldolase . The formation of glycerol, pentitols, and acetic acid was not dependent on added transaldolase but was dependent on the sugar used as the growth substrate and on the sugar used in the in vitro metabolism experiments . The carbon balance showed that the dissimilated carbon could not be accounted for in products when transaldolase was added . The concentration of D-fructose-1,6.-diphosphate in the extracts was not influenced by added transaldolase but was higher with D-xylulose than with D-glucose . Levels of pyruvate, comparable with the two substrates, decreased with increasing levels of transaldolase . Exogenously added transaldolase decreased D-sedoheptulose-7-phosphate levels when D-xylulose was the substrate . The results are discussed in relation to the dissimilation of carbon through the upper part of glycolysis and the pentose phosphate pathway.

Biochimie, 1991 Jun, 73(6), 837 - 44
The nuclear coded mitoribosomal proteins YmL27 and YmL31 are both essential for mitochondrial function in yeast; Graack HR et al.; Using synthetic oligonucleotides deduced from the N-terminal amino acid sequence of purified mitoribosomal protein (mt r-protein) YmL27, the corresponding nuclear gene MRP-L27 of the yeast Saccharomyces cerevisiae has been cloned and sequenced . The MRP-L27 gene codes for 146 amino acids and is located on chromosome X . The mature YmL27 protein consists of 130 amino acids - after cleaving the putative mitochondrial signal peptide - with a net charge of +17 and a calculated relative molecular mass of 14,798 Da . The YmL27 protein as well as the yeast mitoribosomal protein YmL31, which had been characterized and its gene (MRP-L31) cloned previously, is essential for mitochondrial function as shown by the inability of gene disrupted mutants for the MRP-L27 or MRP-L31 genes to grow on non-fermentable carbon sources.

Endocrinology, 1991 Jun, 128(6), 2805 - 14
Alpha 2-macroglobulin is not an acute-phase protein in the rat testis; Stahler MS et al.; Earlier studies from this laboratory have shown that Sertoli cells actively synthesize and secrete a nonspecific protease inhibitor in vitro; N-terminal sequence analysis, subunit structural analysis, and other biological studies revealed that this protein is the homolog of serum alpha 2-macroglobulin . We have now quantified the relative distribution of alpha 2-macroglobulin in the reproductive compartments and their comparison with nonreproductive organs . In serum and all nonreproductive tissues examined, the concentration of alpha 2-macroglobulin progressively decreased with advancing age . However, in both the testis and epididymis, the levels of this protein increased with the age of the animals . Serum alpha 2-macroglobulin levels were consistently higher than those in any other tissues until 60 days when the concentrations of this protein were the highest in the epididymis . The distribution of alpha 2-macroglobulin in various nonreproductive tissues from female rats was similar to that observed for male rats in that its levels tended to decrease with age . However, uterine levels of alpha 2-macroglobulin increased progressively with advancing age, whereas ovarian levels of alpha 2-macroglobulin remained relatively stable with an increase in animal age . As serum alpha 2-macroglobulin is an acute-phase protein in the rat, the response of this protein in the testis to induced inflammation was examined . The concentration of alpha 2-macroglobulin in serum rose about 150-fold after injection of fermented yeast . By contrast, the levels of this protein in rete testis fluid, which is derived exclusively from seminiferous fluid, did not change in response to inflammation . These results suggest that there might be distinctive mechanisms that regulate this protein in the systemic circulation vs . the microenvironment behind the blood-testis barrier in the seminiferous epithelium.

Mol Microbiol, 1991 Jun, 5(6), 1301 - 7
Fermentable sugars and intracellular acidification as specific activators of the RAS-adenylate cyclase signalling pathway in yeast: the relationship to nutrient-induced cell cycle control; Thevelein JM; The RAS proteins of the yeast Saccharomyces cerevisiae fulfil a similar control function on yeast adenylate cyclase as the mammalian Gs proteins on mammalian adenylate cyclase . The discovery that glucose and other fermentable sugars act as specific activators of the RAS-adenylate cyclase pathway in yeast appeared to offer a mechanism for the way in which at least one nutrient would control progression over the start point in the G1 phase of the yeast cell cycle by means of this pathway . Recently, however, evidence has been obtained to show that the glucose-activation pathway of adenylate cyclase is a glucose-repressible pathway and therefore not operative during growth on glucose . In addition, mutant strains were obtained which lack the glucose-activation pathway and show normal exponential growth on glucose . This appears to confine the physiological role of this pathway to control of the transition from the derepressed state (growth on respirative carbon sources) to the repressed state (growth on fermentative carbon sources) by means of an already well-documented cAMP-triggered protein phosphorylation cascade . Intracellular acidification also stimulates the RAS-adenylate cyclase pathway, which might constitute a rescue mechanism for cells suffering from stress conditions . The presence of a nitrogen source does not stimulate the RAS-adenylate cyclase pathway . Although other nutrient signals for the pathway might still be discovered, it appears more and more likely that the well-known requirement of cAMP for progression over the start point of the yeast cell cycle is limited to providing a basal cAMP level rather than acting as a second messenger for an extracellular signal.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein Eng, 1991 Jun, 4(5), 569 - 74
Analysis of the invariant Phe82 residue of yeast iso-1-cytochrome c by site-directed mutagenesis using a phagemid yeast shuttle vector; Inglis SC et al.; A phagemid (pING4) carrying the yeast iso-1-cytochrome c gene was constructed which bears all the elements necessary for replication in yeast and bacteria and may be converted into a single-stranded form of DNA for site-directed mutagenesis and nucleotide sequencing . The recombinant vector was used to create a complete set of 19 amino acid changes at position 82, a phylogenetically conserved phenylalanine residue in mitochondrial cytochrome c . All the different forms of cytochrome c were functional in vivo, based upon their ability to support respiration when the mutant proteins were expressed in a yeast strain (otherwise devoid of cytochrome c) grown on non-fermentable carbon sources, with only the strain containing the Cys82 variant having a substantially decreased growth rate . These results are interpreted in terms of the available structural and functional information previously reported on a subset of cytochrome c proteins with mutations at position 82.

J Anim Sci, 1991 Jun, 69(6), 2585 - 90
Influence of ruminal or duodenal soybean oil infusion on intake, ruminal fermentation, site and extent of digestion, and microbial protein synthesis in beef heifers consuming grass hay; Krysl LJ et al.; Six heifers (two Hereford X Jersey, four Hereford X Longhorn; average BW 278 kg) cannulated at the rumen and duodenum and fed a grass hay (fescue/orchardgrass) diet were used in a replicated 3 X 3 Latin square . Treatments were either no infusion (C), 150 ml of duodenally infused soybean oil (DI), or 150 ml of ruminally infused soybean oil (RI)/heifer twice daily for a total daily infusion of 300 ml of soybean oil . Periods of the Latin square included 18 d for adaptation and 5 d for collection . Forage OM, ADF, NDF, and N intakes were not affected (P greater than .10) by soybean oil infusion . Ruminal (P = .11) and total tract (P less than .10) OM digestibilities were decreased by RI compared with C or DI, but ADF and NDF digestibilities were not affected by treatment . Duodenal N (P less than .05) and microbial N flows were increased (P less than .10) for C and RI compared with DI . Microbial efficiency (g of N/kg of OM truly fermented) was improved (P less than .10) by RI compared with DI but did not differ (P greater than .10) from C . Ruminal pH was lower (P less than .05) with RI than with either C or DI . Ruminal NH3 N, total VFA, and acetate were not affected (P greater than .10) by treatment . Propionate (mol/100 mol) was greater (P less than .05) with RI than with DI and C, but the proportion of butyrate did not differ among treatments . These data indicate minimal direct benefits for improving forage usage as a result of soybean oil infusion with a 100% grass diet; however, animals should realize benefits from additional dietary energy provided by infused lipid.

Mol Gen Genet, 1991 Jun, 227(2), 306 - 17
Mitochondrial mutations restricting spontaneous translational frameshift suppression in the yeast Saccharomyces cerevisiae; Sakai H et al.; The +1 frameshift mutation, M5631, which is located in the gene (oxi1) for cytochrome c oxidase II (COXII) of the yeast mitochondrial genome, is suppressed spontaneously to a remarkably high extent (20%-30%) . The full-length wild-type COXII produced as a result of suppression allows the mutant strain to grow with a "leaky" phenotype on non-fermentable medium . In order to elucidate the factors and interactions involved in this translational suppression, the strain with the frameshift mutation was mutated by MnCl2 treatment and a large number of mutants showing restriction of the suppression were isolated . Of 20 mutants exhibiting a strong, restricted, respiration-deficient (RD) phenotype, 6 were identified as having mutations in the mitochondrial genome . Furthermore, genetic analyses mapped one mutation to the vicinity of the gene for tRNA(Pro) and two others to a region of the tRNA cluster where two-thirds of all mitochondrial tRNA genes are encoded . The degree of restriction of the spontaneous frameshift suppression was characterized at the translational level by in vivo 35S-labeling of the mitochondrial translational products and immunoblotting . These results showed that in some of these mutant strains the frameshift suppression product is synthesized to the same extent as in the leaky parent strain . It is suggested that more than one +1 frame-shifted product is made as a result of suppression in these strains: one is as functional as the wild-type COXII, the other(s) is (are) nonfunctional and prevent leaky growth on non-fermentable medium . A possible mechanism for this heterogenous frameshift suppression is discussed.

Gut, 1991 Jun, 32(6), 665 - 9
Investigation of normal flatus production in healthy volunteers; Tomlin J et al.; Flatulence can cause discomfort and distress but there are few published data of normal patterns and volumes . Twenty four hour collections were made using a rectal catheter in 10 normal volunteers taking their normal diet plus 200 g baked beans . Total daily volume ranged from 476 to 1491 ml (median 705 ml) . Women and men (both n = 5) expelled equivalent amounts . The median daily flatus hydrogen volume was 361 ml/24 h (range 42-1060) and the carbon dioxide volume 68 ml/24 h (range 25-116), three volunteers produced methane (3, 26, and 120 ml/24 h), and the remaining unidentified gas (presumably nitrogen) or gases contributed a median 213 ml/24 h (range 61-476) . Larger volumes of flatus were produced after meals than at other times . Flatus produced at a faster rate tended to contain more fermentation gases . Flatus was produced during the sleeping period, but the rate was significantly lower than the daytime rate (median 16 and 34 ml/h respectively) . Ingestion of a 'fibre free' diet (Fortisip) for 48 hours significantly reduced the total volume collected in 24 hours (median 214 ml/24 h), reduced the carbon dioxide volume (median 6 ml/24 h), and practically eradicated hydrogen production . The volume of unidentified gas was not significantly affected (median 207 ml/24 h) . Thus fermentation gases make the highest contribution to normal flatus volume . A 'fibre free' diet eliminates these without changing residual gas release of around 200 ml/24 h.

Enzyme Microb Technol, 1991 Jun, 13(6), 450 - 5
Evaluation of a new turbidimeter design incorporating a microprocessor-controlled variable pathlength cuvette; Ortmanis A et al.; A microprocessor-controlled, variable pathlength turbidimeter was designed, constructed, and its operation verified and accuracy determined using formazin as a turbidity standard . The turbidimeter was also characterized with the fermentation broths of Saccharomyces cerevisiae and Escherichia coli . The range of turbidities quantified using the instrument spanned from 70 to 1,000 Nephlometric Turbidity Units, with a measurement accuracy between 2% and 11% of the instrument's full-scale reading . The precision of the instrument was determined to be 0.077% . The turbidimeter was used to continuously monitor the biomass concentration of an Escherichia coli fermentation and provided instantaneous concentration estimates which corresponded with gravimetrically determined biomass concentrations to within 12%.

J Ind Microbiol, 1991 Jun, 7(4), 293 - 9
Biochemical and physiological characterization of the efrotomycin fermentation; Chartrain M et al.; An efrotomycin fermentation was characterized through physical, chemical and biochemical studies . Growth of the actinomycete, Nocardia lactamdurans occurred during the first 50 h of the fermentation cycle at the expense of glucose, protein, and triglycerides . The initiation of efrotomycin biosynthesis was observed when glucose dropped to a low concentration . Upon glucose depletion, cell growth ceased and a switch in the respiratory quotient occurred . Efrotomycin biosynthesis was supported by the utilization of soybean oil and starch . Analysis of triglyceride metabolism showed that no diglycerides or monoglycerides accumulated during the fermentation . The activity of extracellular enzymes (lipase, protease, and amylase) increased during the cell growth phase and decreased significantly after 150 h . The concentrations of DNA, tetrahydro-vitamin K2 (a membrane component), and free amino acids in the supernatant increased dramatically late in the fermentation cycle (225 h), indicating massive cell lysis . During this same time period, a reduction in cellular respiratory activity and efrotomycin biosynthesis were observed.

Biotechnology (N Y), 1991 Jun, 9(6), 559 - 61
Fermentation of a yeast producing A . niger glucose oxidase: scale-up, purification and characterization of the recombinant enzyme; De Baetselier A et al.; We have developed a fermentation process to produce up to 3 grams per liter of active, secreted glucose oxidase from a recombinant Saccharomyces cerevisiae . Real-time size-exclusion HPLC analysis is used to monitor enzyme production during fermentation, and purification to more than 95 percent is obtained using only filtration methods . The recombinant enzyme is stable to higher temperatures and a wider pH range than the native Aspergillus niger enzyme, and is free of contaminating amylase, cellulase and catalase.

Biochim Biophys Acta, 1991 May 23, 1058(1), 35 - 7
The low-potential cytochrome c of cyanobacteria and algae; Krogmann DW; A water-soluble, low-potential cytochrome c-550 is found in some cyanobacteria and eukaryotic algae and has regions of sequence similarity to cytochrome c6 . This cytochrome appears to be involved in a fermentation that sustains the organisms during prolonged periods of dark, anaerobic conditions.

Gene, 1991 May 15, 101(1), 97 - 104
Cloning, sequence and chromosomal location of a MEL gene from Saccharomyces carlsbergensis NCYC396; Turakainen H et al.; Yeast strains producing alpha-galactosidase (alpha Gal) are able to use melibiose as a carbon source during growth or fermentation . We cloned a MEL gene from Saccharomyces carlsbergensis NCYC396 through hybridization to the MEL1 gene cloned earlier from Saccharomyces cerevisiae var . uvarum . The alpha Gal encoded by the newly cloned gene was galactose-inducible as is the alpha Gal encoded by MEL1 . A probable GAL4-protein recognition sequence was found in the upstream region of the NCYC396 MEL gene . The gene was transcribed to a 1.5-kb mRNA which, according to the nucleotide sequence, encodes a protein of 471 amino acids (aa) with an Mr of 52,006 . The first 18 aa fulfilled the criteria for the signal sequence, but lacked positively charged aa residues, except the initiating methionine . The enzyme activity was found exclusively in the cellular fraction of the cultures . The deduced aa sequence was compared to the aa sequences of other alpha Gal enzymes . It showed 83% identity with the S . cerevisiae enzyme, but only 35% with the plant enzyme, 30% with the human enzyme and 17% with the Escherichia coli enzyme . With pulsed-field electrophoresis, the MEL gene was located on chromosome X of S . carlsbergensis, whereas the S . cerevisiae var . uvarum MEL1 gene is located on chromosome II.

Gene, 1991 May 15, 101(1), 75 - 80
Sequence diversity of yeast 2 microns RAF gene and its co-evolution with STB and REP1; Xiao W et al.; Despite the extensive study of yeast 2 microns plasmid, the exact function of plasmid-encoded RAF gene is not clear . Variants of 2 microns plasmids from industrial Saccharomyces cerevisiae yeasts were isolated and characterized . Sequencing of RAF alleles revealed about 8% nucleotide and 10% amino acid diversities between 2 microns variants of closely related strains, RAF sequence variations were correlated with STB-REP1 sequence diversity . We also used restriction fragment length polymorphism linkage to screen a large number of yeast strains from different fermentation industries . The results clearly show a tight linkage of STB-REP1-RAF variations . Thus, our observations suggest that plasmid-borne cis- and trans-acting elements co-evolved to form an optimal molecular parasite and that RAF may play a role in active plasmid partitioning.

J Anim Sci, 1991 May, 69(5), 2230 - 43
Effects of dietary energy level and protein source on nutrient digestion and ruminal nitrogen metabolism in steers; Cecava MJ et al.; Four Simmental steers with ruminal, duodenal, and ileal cannulas were used to examine effects of dietary forage: concentrate ratio and supply of ruminally degradable true protein on site of nutrient digestion and net ruminal microbial protein synthesis . Steers (345 kg) were fed ammoniated corn cob (high forage; HF)- or corn cob/ground corn/cornstarch (low forage; LF)-based diets supplemented with soybean meal (SBM) or a combination of corn gluten meal and blood meal (CB) . Diets were fed at 2-h intervals with average DM intake equal to 2.2% of BW . Feeding LF vs HF increased (P less than .05) OM digestion (percentage of intake) in the stomach, small intestine, and total tract . Efficiency of microbial CP synthesis (EMCP; g of N/kg of OM truly fermented) decreased (P less than .05) for LF vs HF (24.1 vs 26.8), but microbial N and total N flows to the small intestine were similar (P greater than .05) between energy levels (average 112 and 209 g/d, respectively) . Total N flows to the small intestine were 13.1% greater (P less than .05) for CB than for SBM because of increased (P less than .05) passage of nonmicrobial N . Feeding SBM vs CB increased (P less than .05) EMCP (27.3 vs 23.3) and microbial N flow to the small intestine (127.5 vs 112.5 g/d), but these increases were not likely due to increased ruminal concentrations of ammonia N (NH3 N) . Decreased (P less than .05) incorporation of NH3 N into bacterial N and slower turnover rates of ruminal NH3 N for SBM vs CB suggest that direct incorporation of preformed diet components into cell mass increased when SBM was fed . Results of this study suggest that the inclusion of ruminally degradable protein in the diet may increase the supply of products from proteolysis and that this can increase EMCP and microbial protein flow to the small intestine.

Biochim Biophys Acta, 1991 May 2, 1089(1), 68 - 76
In vitro expression of bovine opsin using recombinant baculovirus: the role of glutamic acid (134) in opsin biosynthesis and glycosylation; Jansen JJ et al.; Expression levels of functional bovine opsin in the insect cell line IPLB-Sf9 using recombinant baculovirus were shown not to depend on the use of novel transfer vectors (pAcRP23, pAcDZ1) that were reported to improve biosynthesis levels of other proteins in this system . A production of 5 micrograms opsin per 10(6) cells (approx . 1.5% of total cell protein) was achieved by batch fermentation of infected cells in spinner cultures . Infection of the cells in the presence of the glycosyltransferase inhibitor tunicamycin led to the synthesis of the complete protein, which, however, now migrated with a substantially lower Mr . This demonstrates that opsin in insect cells also undergoes N-linked glycosylation and allowed partial purification (10-fold) of the resulting rhodopsin by affinity chromatography over Concanavalin A-Sepharose . Through site-directed mutagenesis (rhod)opsin mutants have been obtained allowing dissection of functional domains of opsin . Amino acid substitutions that involved Glu-134 and/or Arg-135 affected the normal biosynthetic process leading in part to nonglycosylated, to a small extent even incomplete, protein . A number of mutations, that involve other charged residues within the second and third transmembrane domain of the protein, had no effect on the biosynthetic processing of the protein . We therefore suggest that the charge-pair Glu-134-Arg-135 is part of an important internal signal sequence and that alterations in this region may result in incorrect membrane translocation and/or folding of the protein.

J Anim Sci, 1991 May, 69(5), 2123 - 33
Influence of dietary protein and carbohydrate sources on nitrogen metabolism and carbohydrate fermentation by ruminal microbes in continuous culture; Hussein HS et al.; Four diets containing 15% CP were formulated to study the effects of dietary carbohydrate and protein sources on N metabolism and carbohydrate fermentation by ruminal bacteria . Diets were supplied to eight dual-flow continuous culture fermenters during three experimental periods in a randomized complete block design . Six replications were obtained for each diet . Treatments were arranged as a 2 X 2 factorial with two carbohydrate and two protein sources . Carbohydrate sources were corn and barley and protein sources were soybean meal (SBM) and fish meal (FM) . Approximately 40% of the dietary CP was derived from SBM or FM and corn or barley provided 39% of dietary DM . All diets contained 15% grass hay, 20% wheat straw, and 10.1 to 15.3% solka floc (DM basis) . Interactions (P less than .05) were observed between dietary carbohydrate and protein sources, resulting in a depression of VFA production (moles/day) and digestion (percentage) of ADF and cellulose when the corn-FM diet was fed . True OM digestion (percentage) was higher (P less than .05) for SBM than for FM diets and for corn than for barley diets . Although dietary CP degradation (percentage) was higher (P less than .05) for SBM than for FM diets, non-NH3 N in the effluent (grams/day) was not different among diets due to a greater (P less than .05) bacterial N flow for SBM than for FM diets . Despite the lower amino acid (AA) intake (P less than .05) for corn than for barley diets and also for FM than for SBM diets, flows (grams/day) of total AA, essential AA (EAA), and nonessential AA (NEAA) were similar (P greater than .05) among diets . However, greater (P less than .05) total AA, EAA, and NEAA flows (percentage of AA intake) were found for corn than for barley diets and for FM than for SBM diets . It is concluded, therefore, that ruminal escape protein derived from corn or FM has a significant effect on manipulating AA leaving the ruminal fermentation.

J Antibiot (Tokyo), 1991 May, 44(5), 463 - 71
Restricticin, a novel glycine-containing antifungal agent; Schwartz RE et al.; Restricticin (1) is a naturally-occurring antifungal agent which contains triene, pyran and glycine ester functionalities and is unrelated to any previously known family of natural products . This unstable compound, as well as its corresponding N,N-dimethyl derivative (2), have been produced and isolated from both solid and liquid fermentations of Penicillium restrictum . The desglycyl hydrolysis product, restrictinol (3), was produced via the hydrolysis of pure restricticin and as an artifact of the isolation of restricticin.

Biochem Int, 1991 May, 24(2), 199 - 208
Yeast mitochondria (Saccharomyces cerevisiae) contain Ca(2+)-independent phospholipase A1 and A2 activities: effect of respiratory state; Yost RW et al.; We demonstrate that both phospholipase A1 and phospholipase A2 are associated with isolated yeast mitochondria (Saccharomyces cerevisiae) . Activity assays indicate that, unlike most other mitochondrial phospholipases A, the yeast enzymes are Ca(2+)-independent with acidic (pH 4-5) as well as alkaline (pH 8-9) pH optima . Data obtained with mitochondria isolated from either fermenting or respiring cells, and initial observations with a petite strain, strongly suggest that a phospholipase A2 with an acidic pH optimum functions in the in vivo adaptation and maintenance of mitochondrial membranes required for respiration.

Appl Environ Microbiol, 1991 May, 57(5), 1400 - 7
Influence of CO2 and low concentrations of O2 on fermentative metabolism of the ruminal ciliate Polyplastron multivesiculatum; Ellis JE et al.; The effects of ruminal concentrations of CO2 and oxygen on the end products of endogenous metabolism and fermentation of D-glucose by the ruminal entodiniomorphid ciliate Polyplastron multivesiculatum were investigated . The principal metabolic products were butyric, acetic, and lactic acids, H2, and CO2 . 13C nuclear magnetic resonance spectroscopy identified glycerol as a previously unknown major product of D-{1-13C}glucose fermentation by this protozoan . Metabolite formation rates were clearly influenced by the headspace gas composition . In the presence of 1 to 3 microM O2, acetate, H2, and CO2 formation was partially depressed . A gas headspace with a high CO2 content (66 kPa) was found to suppress hydrogenosomal pathways and to favor butyrate accumulation . Cytochromes were not detected (less than 2 pmol/mg of protein) in P . multivesiculatum; protozoal suspensions, however, consumed O2 for up to 3 h at 1 kPa of O2 . Under gas phases of greater than 2.6 kPa of O2, the organisms rapidly became vacuolate and the cilia became inactive . The results suggest that fermentative pathways in P . multivesiculatum are influenced by the O2 and CO2 concentrations that prevail in situ in the rumen.

Vet Microbiol, 1991 May, 27(3-4), 397 - 401
Biochemical typing of Actinobacillus pleuropneumoniae; Sirois M et al.; A study was conducted to evaluate the possibility of using biochemical differences among strains of a given serotype of Actinobacillus pleuropneumoniae as epidemiological markers, to rapidly identify the source of infection in herds affected with swine pleuropneumonia . Out of 38 different biochemical and physiological tests performed on a total of 67 strains belonging to serotypes 1 and 5 of A . pleuropneumoniae, three fermentation tests, glycerol, lactose and raffinose, allowed the classification of serotype 1 strains into 6 phenotypic groups and serotype 5 strains into 4 of these groups . Groups II and III were exclusively composed of serotype 1 strains, whereas the majority of strains in groups I and IV belonged to serotypes 1 and 5 respectively, the latter comprising almost all the serotype 5 studied.

Kansenshogaku Zasshi, 1991 May, 65(5), 537 - 9
{Enteroinvasive Escherichia coli O121: H- isolated from travellers' diarrhea}; Hiruta N et al.; A lactose slow-fermenting, non motile Escherichia coli strain was isolated from a diarrheal patient returning from Indonesia . Examination of virulence of the strain showed that it penetrated into tissue culture cells, and were positive in Sereny test and enzyme-linked immunosorbent assay for detection of enteroinvasive E . coli . A large plasmid responsible for virulence was also detected . Thus the strain was confirmed to be a typical enteroinvasive E . coli . Analysis of O serotype using the antisera against E . coli O1-O170 revealed that the strain had O121 antigen, whose antiserum is not included in the commercial serotyping kit for the diagnosis of diarrheagenic E . coli.

J Assoc Off Anal Chem, 1991 May-Jun, 74(3), 526 - 9
Defined substrate technology method for rapid and specific simultaneous enumeration of total coliforms and Escherichia coli from water: collaborative study; Edberg SC et al.; The defined substrate technology (DST) method is a reagent system designed to enumerate specific target microbes(s) from a mixture of bacteria . The system simultaneously enumerates total coliforms and Escherichia coli directly from a water sample . The reagent contains o-nitrophenyl-beta-D-galactopyranoside (ONPG), which is hydrolyzed by total coliforms to produce a yellow chromogen, and 4-methylumbeilliferyl-beta-D-glucuronide (MUG), which is hydrolyzed and fluoresces when E . coli organisms grow . Noncoliform bacteria are suppressed and cannot metabolize the indicator nutrients . Nine laboratories participated in a field evaluation of the method, which covered a wide range of surface and subsurface water sources and water-processing modalities, including the examination of natural samples . The DST system was compared to multiple-tube fermentation (MTF) (quantitative) and presence-absence (P-A) (qualitative) Standard Methods formats . Comparison of water samples from natural sources by using the most probable number (MPN) procedure showed that the DST test was equivalent to the currently used MTF test . Results from the DST and the qualitative P-A procedure showed that these tests agreed with each other in 94% of the water samples analyzed . Specificity of the DST method was established by subculturing a species consistent with a total coliform or E . coli from each positive tube . Eight laboratories participated in a collaborative study of the method . Each laboratory received 3 concentrations of E . coli (organisms/100 mL); 10 (low); 60 (medium); and 120 (high) . The DST test was inoculated from a split sample of each bacterial density in parallel with Standard Methods brilliant green lactose broth.(ABSTRACT TRUNCATED AT 250 WORDS)

Biol Chem Hoppe Seyler, 1991 May, 372(5), 319 - 24
Synthesis and properties of (R)-2-hydroxyglutaryl-1-CoA . (R)-2-hydroxyglutaryl-5-CoA, an erroneous product of glutaconate CoA-transferase; Klees AG et al.; 1) (R)-2-Hydroxyglutaryl-1-CoA was synthesised starting from (R)-5-oxotetrahydrofuran-2-carboxylic acid (gamma-lactone of (R)-2-hydroxyglutarate) which was converted to the acylchloride and condensed with N-capryloylcysteamine . The lactone ring of the resulting thiolester was opened by acid hydrolysis and the CoA derivative was obtained by transesterification . 2) Pure glutaconate CoA-transferase from Acidaminococcus fermentans catalysed the formation of the 1- and the 5-isomer of (R)-2-hydroxyglutaryl-CoA from acetyl-CoA and (R)-2-hydroxyglutarate . The isomers were separated by HPLC and characterised by their reaction with acetate under the catalysis of the CoA-transferase . V/Km for the 1-isomer was 80 times higher than that for the 5-isomer . 3) Studies with cell-free extracts from A . fermentans showed that only (R)-2-hydroxyglutaryl-1-CoA but not its 5-isomer was dehydrated to glutaconyl-1-CoA . The data indicate that (R)-2-hydroxyglutaryl-5-CoA is an erroneous product of glutaconate CoA-transferase which only occurs in vitro.

Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi, 1991 May, 24(2), 229 - 39
Anaerobic growth and oxygen toxicity of Rhizopus cultures isolated from starters made by solid state fermentation; Lin MS et al.; To explore the relationship between Rhizopus growth and its microaerophilic characteristics the present study was undertaken . A survey of 18 Rhizopus cultures growing in anaerobic or microaerobic condition found that 11 of the cultures grew quite well under microaerobic condition, but all the cultures grew poorly under absolutely anaerobic condition . Among the 18, 8 showed definitely banded mycelial growth below the surface of the medium in the tube . Six of 18 cultures--RT-1-8, RT-43, RT-46, A-1, C-1, and E-1--grew with much aerial hyphae when they were cultivated on media supplemented with different detoxifying agents under aerobic condition . These six strains are comparatively sensitive to oxygen toxicity (H2O2 or O2- or OH.) under aerobic condition, as many microaerophilic bacteria are . There were nine strains whose aerial hyphal growth was greatly enhanced by the presence of Aspergillus niger catalase . However, the growth of the majority of the cultures was not influenced by supplements of bovine liver catalase or bovine liver superoxide dismutase . In conclusion, some Rhizopus cultures from the starters exhibited both microaerophilic and aerobic growth . The phenomena of growth in low O2 condition, and the subsurface growth of mycelia in tubes, may provide a clue to exploitation of the microaerophile-like characteristics in some starter molds.

J Am Diet Assoc, 1991 May, 91(5), 590 - 6, 599
Dietary fiber and bowel function in tube-fed patients; Frankenfield DC et al.; In tube-fed patients, dietary fiber is often used to manage constipation/diarrhea . Dietary fiber consists of water-soluble and insoluble plant compounds that are resistant to digestion by small-bowel enzymes but are fermented to varying degrees by colonic bacteria . Many physiologic effects of fiber may be related to the degree of fermentation . Few controlled studies of fiber-containing tube feedings have been performed . These studies have limitations and are nondefinitive as to whether fiber prevents or controls constipation/diarrhea . Constipation in tube-fed patients has not been shown to respond to mixed soluble/insoluble fiber in the few studies performed to date . Likewise, fiber may be of only limited benefit in controlling diarrhea in acute illness because of such factors as stress or medication . Fiber does play a role in maintaining gut integrity in all patients, whether they have diarrhea or not . Fiber may be recommended as part of a standard tube-feeding regimen to help assure gut mucosal integrity but not specifically to treat constipation/diarrhea . Further studies are necessary before the role of fiber in the management of constipation/diarrhea in tube-fed patients is determined.

Food Addit Contam, 1991 May-Jun, 8(3), 291 - 8
Influence of nitrate, ascorbic acid, and nitrate reductase microorganisms on N-nitrosamine formation during Korean-style soysauce fermentation; Sung NJ et al.; Traditional Korean soysauce samples were collected from households in Chinju, Gyeongnam, Korea and analysed for volatile N-nitrosamines . Five of 24 samples contained NDMA (range = 1.6-10.4 micrograms/l) which was the only volatile N-nitroso compound found . Soysauce made from well water contained NDMA more often (4 of 6 samples) than soysauce made from tap water (1 of 18) . This suggests that the water source is a determinate in the NDMA content of soysauce, probably due to a higher nitrate content of well water . The source of salt used did not clearly influence NDMA content . Soysauce was prepared in the laboratory using traditional methods but with 0 to 400 mg/l nitrate and in some cases made 6.5 to 65 mM in ascorbic acid and fermented for 120 days . The NDMA content of the samples was positively correlated with increasing nitrate concentration . Nitrate at 400 mg/l resulted in an NDMA content of 203 micrograms/l . Ascorbic acid substantially inhibited NDMA formation . All samples contained large numbers of nitrate reductase-containing organisms (greater than 1 x 10(7) CFU/ml).

J Gen Microbiol, 1991 May, 137 ( Pt 5), 1201 - 6
Pathways of glutamate catabolism among Fusobacterium species; Gharbia SE et al.; Glutamate is a major source of energy for Fusobacterium species but its mode of catabolism has not hitherto been elucidated . Cell suspensions of F . nucleatum and F . varium, as representative species from the oral cavity and gastrointestinal tract, respectively, both decarboxylated position-labelled glutamate but by different pathways . 14CO2 was released only from C-5 by F . nucleatum whereas F . varium decarboxylated glutamate at either C-1 or C-5 . In both species, 2 mols of glutamate fermented yielded 2 mols of acetate and 1 mol of butyrate, suggesting the possibility of three metabolic pathways: the 2-oxoglutarate, mesaconate and 4-aminobutyrate pathways . Enzymes representative of the three pathways were assayed for in cell-free extracts of fusobacteria . All species tested possessed high levels of both glutamate dehydrogenase and 2-oxoglutarate reductase, indicating the presence of the 2-oxoglutarate pathway . Enzymes representative of the mesaconate pathway were detected in F . sulci, F . ulcerans, F . mortiferum and F . varium, while the latter two species also possessed the 4-aminobutyrate pathway . The pathways of glutamate catabolism therefore bore no relationship to the site of isolation of the fusobacteria tested but instead correlated with their chemotaxonomic properties . Thus, F . varium, F . mortiferum, F . ulcerans and F . sulci, which possess a peptidoglycan structure based on diaminopimelic acid, have either two or three pathways for glutamate catabolism whereas F . nucleatum and other species that have a lanthionine-based murein metabolized glutamate solely by the 2-oxoglutarate pathway.

J Anim Sci, 1991 May, 69(5), 2134 - 46
Ruminal protein metabolism and intestinal amino acid utilization as affected by dietary protein and carbohydrate sources in sheep; Hussein HS et al.; Eight wether lambs fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 4 x 4 Latin square design to study the effects of carbohydrate and protein sources on ruminal protein metabolism and carbohydrate fermentation and intestinal amino acid (AA) absorption . Treatments were arranged as a 2 x 2 factorial . Carbohydrate sources were corn and barley; protein sources were soybean meal (SBM) and fish meal (FM) . Diets contained 15.5% CP, of which 40% was supplied by SBM or FM . Corn or barley provided 39% of dietary DM that contained equal amounts of grass hay and wheat straw . Fish meal diets produced a lower (P less than .05) ruminal NH3 concentration and resulted in less CP degradation and bacterial protein flow to the duodenum than did SBM diets . Replacing SBM with FM increased (P less than .05) ruminal digestion of all fiber fractions . In addition, cellulose and hemicellulose digestibilities in the rumen tended to increase (P greater than .05) when barley replaced corn in the FM diets . Carbohydrate x protein interactions (P less than .05) were observed for OM digestion in the rumen and AA absorption in the small intestine (percentage of AA entering); these interactions were highest for the barley-FM diet . These results suggest that feeding FM with barley, which is high in both degradable carbohydrate and protein, might benefit ruminants more than feeding FM with corn, which is high in degradable carbohydrate but relatively low in degradable protein.

J Antibiot (Tokyo), 1991 May, 44(5), 486 - 91
A new topoisomerase-II inhibitor, BE-10988, produced by a streptomycete . I . Taxonomy, fermentation, isolation and characterization; Oka H et al.; A new topoisomerase inhibitor, BE-10988, was isolated from the culture broth of a strain of actinomycetes . The producing strain had a close resemblance to Streptomyces fimicarius and Streptomyces xanthocidicus . The active principle was extracted from the whole broth of strain BA10988 with ethyl acetate and purified by silica gel chromatography and by HPLC . BE-10988 increased DNA-topoisomerase complex formation and inhibited the growth of both doxorubicin-resistant and vincristine-resistant P388 murine leukemia cell lines, as well as sensitive P388 cell lines.

Biotechnol Prog, 1991 May-Jun, 7(3), 246 - 50
Effect of dissolved oxygen control on growth and antibiotic production in Streptomyces clavuligerus fermentations; Yegneswaran PK et al.; A proportional-integral control system was used to control dissolved oxygen in a fermentor at constant shear and mass transfer conditions . Growth and antibiotic production in Streptomyces clavuligerus were studied at different dissolved oxygen levels during the fermentation . Three protocols were employed: no-oxygen control to provide a base case, oxygen controlled to a preset saturation level throughout the fermentation, and oxygen controlled at a high level only during the growth phase . The last protocol was aimed at optimizing the consumption of oxygen . Lower specific growth rates and cephamycin C yields were obtained when dissolved oxygen was controlled at 50% throughout the fermentation, compared to the base case . A 2.4-fold increase in the final cephamycin yield was observed when dissolved oxygen was controlled at saturation levels during the growth phase, compared to the experiments without dissolved oxygen control . This enhancement in yield was independent of the dissolved oxygen (DO) level after exponential growth, in the range of 50-100% saturation . The most effective control strategy, therefore, was to control DO only during active growth when the biosynthetic enzymes were probably synthesized.

Cytotechnology, 1991 May, 6(1), 55 - 63
On-line monitoring of monoclonal antibody formation in high density perfusion culture using FIA; Fenge C et al.; An automated flow injection system for on-line analysis of proteins in real fermentation fluids was developed by combining the principles of stopped-flow, merging zones flow injection analysis (FIA) with antigen-antibody reactions . IgG in the sample reacted with its corresponding antibody (a-IgG) in the reagent solution . Formation of insoluble immunocomplexes resulted in an increase of the turbidity which was determined photometrically . This system was used to monitor monoclonal antibody production in high cell density perfusion culture of hybridoma cells . Perfusion was performed with a newly developed static filtration unit equipped with hydrophilic microporous tubular membranes . Different sampling devices were tested to obtain a cell-free sample stream for on-line product analysis of high molecular weight (e.g., monoclonal antibodies) and low molecular weight (e.g., glucose, lactate) medium components . In fermentation fluids a good correlation (coefficient: 0.996) between the FIA method and an ELISA test was demonstrated . In a high density perfusion cultivation process mAb formation was successfully monitored on-line over a period of 400 h using a reliable sampling system . Glucose and lactate were measured over the same period of time using a commercially available automatic analyser based on immobilized enzyme technology.

Biotechnology (N Y), 1991 May, 9(5), 473 - 6
Actinorhodin production by Streptomyces coelicolor and growth of Streptomyces lividans are improved by the expression of a bacterial hemoglobin; Magnolo SK et al.; Secondary metabolite production by Streptomyces is often highly sensitive to oxygen supply, which can be limiting in large-scale fermentations . In an attempt to improve oxygen utilization by the cells, we expressed a heterologous bacterial hemoglobin gene in Streptomyces coelicolor and Streptomyces lividans . Hemoglobin expression was demonstrated by immunoblot analysis and carbon monoxide binding activity . In batch fermentations run under reduced aeration, the expression of hemoglobin in S . coelicolor resulted in a ten-fold increase in specific yields of the aromatic polyketide, actinorhodin . Actinorhodin yields were also much less sensitive to aeration conditions in the hemoglobin-expressing strain . In addition, hemoglobin-expressing S . lividans cells grown under reduced aeration had higher final cell densities and exhibited greater oxygen consumption rates than non-expressing cells.

J Biol Chem, 1991 Apr 25, 266(12), 7688 - 93
Subunit function in eukaryote cytochrome c oxidase . A mutation in the nuclear-coded subunit IV allows assembly but alters the function and stability of yeast cytochrome c oxidase; Lightowlers R et al.; Strains of the yeast Saccharomyces cerevisiae disrupted in YCOX4, the nuclear gene encoding cytochrome c oxidase subunit IV, do not assemble a functional or spectrally visible oxidase . We report the characterization of a yeast strain, RM1, expressing a mutated YCOX4 gene which is temperature sensitive for respiration at 37 degrees C, but incorporates cytochrome aa3 over all growth temperatures . The mutant enzyme is less stable than the wild type, with subunit IV readily proteolyzed without gross denaturation of the complex but with a concomitant loss of oxidase activity . When grown fermentatively at 37 degrees C, cytochrome c oxidase from the mutant strain had a turnover number of less than 3% of the normal complex, while Km values and subunit levels were comparable to normal . Thus alterations in subunit IV can perturb the enzyme structure and alter its catalytic rate, implying a role for this subunit in cytochrome c oxidase function as distinct from assembly.

FEBS Lett, 1991 Apr 22, 282(1), 119 - 21
Analysis of 13C and 15N CPMAS NMR-spectra of soil organic matter and composts; Almendros G et al.; 15N and 13C CPMAS spectra of composted plants are presented . The plants (L . rigidium and Zea mays) were grown in 15N enriched medium and fermented for several months until an approx . 80% of the dry matter was lost . In all 15N spectra the secondary amide/peptide peaks at 87 ppm contributes more than 80% of the total intensity . No new 15N peaks are formed during the fermentation process . Older attempts to assign a significant fraction of humic acid nitrogen to heteroaromatic structures formed in the fermentation process are thus most probably wrong.

J Anim Sci, 1991 Apr, 69(4), 1775 - 87
Effects of feeding alkaline hydrogen peroxide-treated wheat straw-based diets on intake, digestion, ruminal fermentation, and production responses by mid-lactation dairy cows; Cameron MG et al.; The objective of this experiment was to determine the effects of feeding different levels of alkaline hydrogen peroxide-treated wheat straw (AHP-WS) in the diet on feed intake, nutrient digestion, ruminal fermentation, and production responses in mid-lactation dairy cows . Eight Holstein cows, averaging 147 d postpartum, were used in two replications of a 4 x 4 Latin square design . Complete mixed diets consisted of 70% forage and 30% concentrate (DM basis) with various levels of AHP-WS, alfalfa haylage, and corn silage as forage sources . Treatments contained 0 (control), 20.0, 40.1, or 60.0% AHP-WS in the diet . A quadratic effect (P = .08) of AHP-WS level on DMI was noted, with values of 2.16, 22.3, 20.8, and 18.9 kg/d for the control, 20.0, 40.1, and 60.0% AHP-WS treatments, respectively . Apparent digestibilities of DM, OM, CP, and ADF were not affected (P greater than .10) by replacing haylage and corn silage with increasing amounts of AHP-WS in the diet, but there was a linear increase (P = .03) in NDF digestibility (44% for control vs 59% for the 60.0% AHP-WS diet) and a parallel decrease (P less than .05) in cell content digestibility (82 vs 70% for these two diets) . Yields of milk and 4% fat-corrected milk (FCM) were decreased (quadratic; P = .0001) as the level of AHP-WS increased in the diet . The addition of AHP-WS to the diet decreased the milk fat percentage from 3.72 to 3.60% (quadratic; P = .05) and decreased milk protein percentage from 3.27 to 3.13% (linear; P = .0001) . Cows fed the higher levels of AHP-WS had linear increases (P = .0001) in ruminal concentrations of total VFA (128.0 mM for control vs 136.0 mM for the 60.0% AHP-WS treatment) and molar proportion of acetate, resulting in a quadratic effect (P less than .0001) on the acetate:propionate ratio . These data indicate that feeding the 40.1 and 60.0% AHP-WS diets lowered digestible DM and OM intakes, which resulted in reduced 4% FCM yield as nutrient intakes were decreased compared with cows fed the 20.0% AHP-WS diet or the control diet containing alfalfa haylage and corn silage . Although substituting AHP-WS for haylage and corn silage increased NDF digestibility and tended to increase digestible NDF intake, milk production was depressed because digestible DMI decreased.

J Anim Sci, 1991 Apr, 69(4), 1795 - 803
Effects of animal-to-animal exchange of ruminal contents on the feed intake and ruminal characteristics of fed and fasted lambs; Cole NA; Four Suffolk x Hampshire wether lambs averaging 55 kg with permanent ruminal cannulas were used in a 4 x 4 Latin square design to determine the effects of exchange of ruminal contents between fed and fasted lambs on subsequent DMI and ruminal characteristics . Lambs were fed a pelleted 70% roughage diet at 2% of BW for 17 d . During each period of the Latin square two lambs were deprived of feed and water for 3 d . At the end of the fasting period ruminal contents from one fed and one fasted lamb were exchanged . Lambs were then given ad libitum access to feed for 8 d, during which DMI, feeding pattern, and ruminal characteristics were monitored . Measurements of ruminal volume determined by total collection and indigestible marker (lithium sulfate) suggested that only about 50% of total ruminal contents were actually exchanged . Fasted lambs had lower (P less than .05) DMI, ruminal fermentative capacity, ruminal DM weight, and ruminal DM percentage than fed lambs during the first 4 d of realimentation . Exchange of ruminal contents did not (P greater than .10) affect DMI, feeding pattern, ruminal fluid pH, ruminal fermentative capacity, ruminal contents DM percentage, ruminal nucleic acid concentration, or VFA . Dosing fasted lambs with ruminal contents from nonfasted lambs reduced (P less than .05) ruminal liquid volume, dry weight of ruminal contents, and propionate concentration . Results of this trial are interpreted to indicate that although decreased ruminal function is a factor in the low feed intakes of fasted ruminants, the possibility of increasing postfast feed intake via improved ruminal function is limited because other metabolic factors may play a more important role.

J Anim Sci, 1991 Apr, 69(4), 1733 - 40
Influence of feeding Aspergillus oryzae fermentation extract on the milk yields, eating patterns, and body temperatures of lactating cows; Gomez-Alarcon RA et al.; Trials were conducted to evaluate effects of a fermentation extract of Aspergillus oryzae (AO) on milk production and composition, diet digestibility, and rectal temperature changes in lactating dairy cows . Treatments were incorporated as a top dressing at the morning feeding and consisted of control (90 g/d of ground sorghum) or AO (3 g of culture + 87 g of ground sorghum daily) . Twenty-four mid-lactation Holstein cows were paired for production in Lactation Trial 1 (LT-1) . In Lactation Trial 2 (LT-2), 46 cows (20 primiparous and 26 multiparous) in early lactation were used . Trials lasted 12 wk . In LT-1, AO supplementation increased milk yields only at 2 (P less than .05) and 8 wk (P less than .10) of treatment . Rectal temperatures were lower (P less than .05) for cows fed AO for 4 of 10 readings made during summer . Supplementation of AO culture in LT-2 (early lactation cows) increased milk production and feed efficiency (P less than .05) . Inner ear temperatures tended to be lower (P less than .11) for cows fed AO . Digestion trials, conducted at the end of lactation trials, used Cr2O3 as an indigestible marker . In Digestion Trial 1, digestibilities were not significantly (P greater than .10) affected by AO supplementation . However, in Digestion Trial 2, AO increased (P less than .05) digestibilities of DM, OM, CP, NDF, and ADF . Length and number of meals were not affected (P greater than .10) by feeding AO . In summary, milk yields, efficiency of milk production, and nutrient digestibilities were higher for early lactation cows fed a high-concentrate diet supplemented with 3 g of AO/d . Mid-lactation cows fed a lower-energy diet were less responsive to AO than early lactation cows, though similar trends were shown.

J Anim Sci, 1991 Apr, 69(4), 1678 - 87
Supplemental corn grain for steers grazing native rangeland during summer; Pordomingo AJ et al.; Effects of supplemental corn grain on forage OM intake (FOMI), digesta kinetics, ruminal fermentation patterns, in vitro OM digestibility (IVOMD), and in situ OM digestion were examined in steers grazing summer blue grama rangeland in northeastern New Mexico during July and August 1988 . Sixteen ruminally cannulated steers (average BW 507 kg) were allotted to four treatments and individually fed whole-shelled corn at 0, .2, .4, and .6% of BW in a complete random design with repeated measurements over time . Forage OMI decreased linearly (P = .02) with increasing levels of supplemental corn; however, a tendency toward greater FOMI, as well as faster particulate and fluid passage, was observed when corn was fed at .2% of BW compared with 0, .4, or .6% of BW . Molar proportions of butyrate increased (P less than .10) but molar proportions of acetate and propionate, ruminal pH, and total VFA concentration did not change (P greater than .10) with added corn . Added corn linearly decreased (P less than .10) ruminal ammonia N concentrations in July, but patterns were inconsistent in August . A cubic response (P less than .05) for in situ OM disappearance with added corn was noted after 24, 72, and 96 h of incubation . Supplemental whole corn fed at .2% of BW had no detrimental effects and tended to increase FOMI . However, supplemental corn fed at .4 or .6% of BW decreased FOMI compared with 0 or .2% of BW.

J Anim Sci, 1991 Apr, 69(4), 1389 - 96
Influence of ardacin supplementation on feedlot performance and digestive function of cattle; Zinn RA et al.; A feedlot growth-performance trial and a metabolism trial were conducted to evaluate a dose response to ardacin (a glycopeptide antibiotic) . Treatments consisted of an 88% concentrate finishing diet supplemented to contain (DM basis) 0, 8.25, 16.5., or 33 mg ardacin/kg . The growth-performance trial (129 d) involved 120 heifers and 120 steers in a randomized complete block design . There were no interactions (P less than .10) between sex and response to ardacin . Average daily gain increased (P less than .05) and DM conversion decreased (P less than .01) with increasing levels of ardacin supplementation . At the 33 mg/kg level of supplementation, ADG and DM conversion were improved 10.6 and 5.6%, respectively . Four Holstein steers (344 kg) with cannulas in the rumen and proximal duodenum were used to evaluate treatment effects on characteristics of digestion . There were cubic effects of ardacin on ruminal starch digestion (P less than .05), microbial N synthesis (MNS, P less than .10), and microbial efficiency (MNEFF, grams of MNS/kilogram of OM fermented) . For the 16.5 and 33 mg/kg levels of supplementation, ruminal starch digestion was increased 4.9%, and MNS and MNEFF were decreased 12.9 and 15.6%, respectively . Postruminal and total tract digestion of N increased linearly (P less than .10) with ardacin supplementation . Total tract digestion of OM, ADF, and starch were not affected (P greater than .10) . Ardacin did not influence (P greater than .10) ruminal pH or molar VFA proportions . It is concluded that supplementation of a finishing diet with 33 mg ardacin/kg will enhance ADG and DM conversion of feedlot steers and heifers.

Appl Environ Microbiol, 1991 Apr, 57(4), 918 - 23
Glucose-stat, a glucose-controlled continuous culture; Kleman GL et al.; A predictive and feedback proportional control algorithm, developed for fed-batch fermentations and described in a companion paper (G . L . Kleman, J . J . Chalmers, G . W . Luli, and W . R . Strohl, Appl . Environ . Microbiol . 57:910-917, 1991), was used in this work to control a continuous culture on the basis of the soluble-glucose concentration (called the glucose-stat) . This glucose-controlled continuous-culture system was found to reach and maintain steady state for 11 to 24 residence times when four different background glucose concentrations (0.27, 0.50, 0.7, and 1.5 g/liter) were used . The predictive-plus-feedback control system yielded very tight control of the continuous nutristat cultures; glucose concentrations were maintained at the set points with less than 0.003 standard error . Acetate production by Escherichia coli B in glucose-stats was found not to be correlated with the level of steady-state soluble-glucose concentration.

Appl Environ Microbiol, 1991 Apr, 57(4), 910 - 7
A predictive and feedback control algorithm maintains a constant glucose concentration in fed-batch fermentations; Kleman GL et al.; A combined predictive and feedback control algorithm based on measurements of the concentration of glucose on-line has been developed to control fed-batch fermentations of Escherichia coli . The predictive control algorithm was based on the on-line calculation of glucose demand by the culture and plotting a linear regression to the next datum point to obtain a predicted glucose demand . This provided a predictive "coarse" control for the glucose-based nutrient feed . A direct feedback control using a proportional controller, based on glucose measurements every 2 min, fine-tuned the feed rate . These combined control schemes were used to maintain glucose concentrations in fed-batch fermentations as tight as 0.49 +/- 0.04 g/liter during growth of E . coli to high cell densities.

Anat Rec, 1991 Apr, 229(4), 521 - 4
Pathways of lymph flow from the intestine of the horse; Nikles SA et al.; The intestine of horses differs from that of most other domestic animals in having a huge ascending colon and cecum, which together act as a large fermentation vat . The lymph drainage from this intestine occurs through a complex network of lymph vessels and lymph nodes, of which there are several thousand . The pathways taken by lymph through these vessels and nodes were studied by tracing injections of dye, by examining Microfil casts, and with light and transmission electron microscopy . Lymph vessels transporting lymph from the intestinal wall generally terminate on a single node within a group of primary nodes . Efferent lymphatics form networks in the immediate vicinity of groups of nodes . In these networks, the vessels branch, anastomose, entwine amongst one another, and sometimes form recirculating loops . Usually 2-9 lymphatic vessels course away from these networks to secondary or higher-order nodes in both local and more central locations . Vessels reaching these nodes generally terminate on more than one node within each group . This pattern of lymph distribution is repeated as lymph passes through a succession of five or more nodes before flowing into the cisterna chyli . The complexity of the lymph pathways, it is suggested, would promote the mixing of lymph from different parts of the intestine and from different nodes, thus collating, integrating, and potentiating the immunological responses of these nodes . The walls of lymphatic vessels are well endowed with smooth muscle cells and elastic fibres, suggesting that intrinsic contractility of these vessels is a major mechanism in the propulsion of lymph from the intestine of the horse.

J Bacteriol, 1991 Apr, 173(8), 2644 - 8
Nucleotide sequence and characterization of the sfs1 gene: sfs1 is involved in CRP*-dependent mal gene expression in Escherichia coli; Kawamukai M et al.; We have cloned at least 12 different Escherichia coli genes which enable strain MK2001 to use maltose . The genes were designated sfs1 through sfs12 (sugar fermentation stimulation) . Previously, one (sfs7) of them was mapped at 65 min on the E . coli chromosome and identified as nlp, which has high homology to repressor protein (Ner) of Mu phage, which contains a putative DNA binding region (Y.-L . Choi, T . Nishida, M . Kawamukai, R . Utsumi, H . Sakai, and T . Komano, J . Bacteriol . 171:5222-5225, 1989) . In this study, another gene (sfs1) located at 3.5 min was newly found and analyzed . The nucleotide sequence of sfs1 encoded a protein of 234 amino acids (molecular mass, 26,227 Da) which also has a putative DNA binding domain . Overexpression of the sfs1 gene in MK2001 resulted in a 10-fold increase of amylomaltase, which was still dependent on MalT . These results suggest that Sfs1 could be a new regulatory factor involved in maltose metabolism.

Oral Microbiol Immunol, 1991 Apr, 6(2), 76 - 80
Aspartate and asparagine as electron acceptors for Wolinella recta; Ohta H et al.; Since fumarate and nitrate are not usually available in the oral ecosystem, it was investigated whether aspartate and asparagine could be used as alternative electron acceptors by Wolinella recta, which is strictly dependent on a respiratory metabolism with formate or H2 as electron donors . Both aspartate and asparagine were indeed shown to support growth of W . recta with formate as electron donor . Fermentative growth with aspartate alone was not possible . Succinate was the major end-product and was formed in equimolar quantities with respect to the amount of formate consumed . The consumption of aspartate and asparagine, on a molar basis, was 10-30% higher than that of formate . Cell-free extracts were prepared from cells grown with formate + fumarate, formate + aspartate, formate + asparagine, and formate + fumarate + aspartate . All these extracts contained high activities of asparaginase, aspartate ammonia-lyase and fumarate-reductase, but no significant activity of aspartate aminotransferase was detected, indicating that fumarate was synthesized directly from aspartate and subsequently reduced to succinate . Based on these results it seems likely that aspartate and asparagine can serve as natural electron acceptors for W . recta in periodontal lesions in which proteolytic bacteria abound.

J Med Microbiol, 1991 Apr, 34(4), 219 - 23
Oxygen uptake and H2O2 production by fermentative Mycoplasma spp; Miles RJ et al.; Oxygen uptake and H2O2 accumulation during the metabolism of glucose and glycerol by whole cells, and of L-alpha-glycerophosphate (GP) and NADH by cells lysed with Triton, was determined for the type strains of six fermentative Mycoplasma species . Oxidation of glucose and of NADH by M . mycoides, M . pneumoniae and M . putrefaciens was accompanied by the accumulation of relatively small quantities of H2O2 (less than 0.05 mol/mol O2), though larger quantities (0.17-0.24 mol/mol O2) were produced by M . dispar . M . fermentans and M . canis were distinguished from the other strains used in that O2 uptake in the presence of glucose could not be demonstrated . However, metabolism of glucose was indicated by a reduction in the pH of the suspending medium and lysed cells oxidised NADH with the production of approximately 1.0 mol H2O2/mol O2 taken up . Glycerol was oxidised by all the strains studied except M . fermentans, and large quantities of H2O2 (0.48-1.07 mol/mol O2) accumulated . Cells of the glycerol-oxidising strains, lysed with Triton, oxidised GP with the production of approximately 1.0 mol H2O2/mol O2 utilised, which indicated the presence of a GP oxidase . The importance of H2O2 production as a factor in the pathogenicity of some mycoplasmas might depend upon the availability of glycerol in vivo.

J Biol Regul Homeost Agents, 1991 Apr-Jun, 5(2), 45 - 51
Protective effect of fungal growth product (6MFA), assessed therapeutically against Ehrlich's ascites tumor in Swiss mice; Mall SA et al.; 6MFA is a growth product of the fungus Aspergillus ochraceus (ATCC 28706) obtained by fermentation in stationary culture . It has both interferon inducing and antiviral properties, in vivo and in vitro, with a relatively high margin of safety (9, 17, 18) . Ehrlich's ascites tumor bearing Swiss albino male mice were treated with 0.5 ml of acqueous preparation of 6MFA (0.75 mg total solids) i.p . in a therapeutic regimen schedule; the sham treated mice received only PBS . 6MFA treatment produced an increase in mean survival time over the untreated controls, restricted the body weight increase due to ascites and decreased the rate of mortality . As much as 100% of survival response was obtained in the group treated with 0.5 ml of 6MFA at the rate of one inoculation per week for 5 weeks . In general a dose-dependent response was seen in the antitumor effect of 6MFA against Ehrlich's ascites tumor in Swiss mice . Delay in administration of 6MFA to tumor bearing mice affected the survival rate.

Biochem Soc Trans, 1991 Apr, 19(2), 513 - 4
Analysis of pH-induced population oscillations of Saccharomyces cerevisiae and Escherichia coli using photon correlation spectroscopy; Jepras RI et al.; Following a recent successful application of p.c.s . to liquid chromatography in the biotechnology industry, its usefulness as a contamination monitor in the fermentation industry was assessed . It was found that: (i) the intensity bias of the technique limits its uses to the detection of contaminants when they are larger than the host; (ii) the inherent heterogeneity of microbial cultures prevents the use of multiangle studies, and (iii) the large size of bacteria make the use of p.c.s . in flowing, on-line systems impractical.

Eur J Clin Nutr, 1991 Apr, 45(4), 221 - 6
Is colonic fermentation minimized by increasing meal frequency?
Brighenti F, Ciappellano S, Vuksan V, Rao AV, Wolever TM, Jenkins A, Jenkins DJ, Testolin G.
It has been suggested that, although increasing meal frequency has metabolic advantages in terms of carbohydrate and lipid metabolism, the efficiency of small intestinal absorption may be enhanced, thus reducing the extent of colonic fermentation . Since this may be undesirable, we have tested whether increasing meal frequency reduces the amount of carbohydrate fermented into the colon . Accordingly, seven healthy male volunteers took, in random order, two identical 2-week metabolic diets divided into either seventeen or three meals daily . On day 13 of each period measurements were made throughout the day of breath H2 and serum acetate, as markers of colonic fermentation . Mean levels of both breath H2 and acetate were similar on both diets, being lower on nibbling by 3.2 +/- 0.8 ppm and 25 +/- 9 mumols/l respectively (not significant) . This study failed to demonstrate an effect of more efficient carbohydrate absorption with increased meal frequency.

Int Surg, 1991 Apr-Jun, 76(2), 81 - 3
Amoebic liver abscess . Review of 220 cases; Hai AA et al.; Two hundred and twenty cases of amoebic liver abscess were seen between 1981-1986 . The majority were young or middle aged males belonging to the lower socio-economic group and 85% gave a history of drinking toddy (fermented palm juice) . The highest incidence of the disease occurred during the peak toddy season (April to July) . Toddy drinkers become susceptible perhaps because of the large dose of Entamoeba histolytica and bacteria ingested with the drink, associated malnutrition, poor hygiene, hepatic dysfunction and possible suppression of amoebistatic substance . Useful investigations consisted of skiagram and ultrasonography, the later being sometimes used to guide the aspiration needle to abscesses situated at unconventional sites . Over 88 per cent responded well to conservative treatment with aspiration(s) . Laparotomy was required in slightly over 10% of cases and in these the mortality was 12% as compared to 2% with conservative treatment . Although a large amount of liver tissue appears to be destroyed, the residual liver damage is clinically, biochemically, macroscopically and microscopically minimal.

Arch Tierernahr, 1991 Apr, 41(3), 303 - 10
{Effect of flavomycin on the apparent digestibility of crude nutrients in wethers, parameters of rumen fermentation in cattle and feed intake and weight gain of heifers}; Flachowsky G et al.; Three experiments with five wether each were carried out in order to investigate the influence of various levels of flavomycin (0, 5 and 10 mg per animal and day) on apparent digestibility of artificially dried grass . A short time individual feeding experiment (42 days) with 9 bulls and a long term individual feeding experiment (225 days) with 52 heifers were conducted . Animals consumed 0 or 30 mg flavomycin per day . Parameters of rumen fermentation were investigated . Feed intake and weight gain were measured in the experiment with heifers . Flavomycin did not significantly influence the apparent digestibility of organic matter and crude nutrients as well as parameters of rumen fermentation . Flavomycin did not influence dry matter intake, but increased significantly weight gain (49 g per animal and day, 10.5%) and reduced feed and energy required per kg weight gain (10.6%) in heifers . The reasons of ergotropic effects of flavomycin are mostly unknown at present.

Curr Genet, 1991 Apr, 19(4), 301 - 8
Mutational studies of the major tRNA region of the S . cerevisiae mitochondrial genome; Elelj-Fridhi N et al.; The major tRNA genes in S . cerevisiae mitochondria are contained within a 20 kb segment of the mitochondrial DNA . In order to analyze the functional role of this region we have isolated several mitochondrial mutations, which are temperature-sensitive for growth on non-fermentable carbon sources . These mutations, localized in the major tRNA cluster region, can be classified in different groups according to their (a) genetic and physical localization, (b) spectrum of suppression and (c) biochemical characteristics . Some of these are mutations in tRNA genes which affect tRNA function; others alter the synthesis of the gene product . Finally, we found two mutations localized in, or in the vicinity of, the open reading frame RF2 . RF2 has been postulated to be a maturase-like protein (Michel 1984) but no function for it has yet been demonstrated . The existence of defective mutants may confirm that RF2 is indeed necessary for mitochondrial biogenesis and so allow for a study of the expression of this gene.

J Dairy Sci, 1991 Apr, 74(4), 1321 - 36
Effects of urea and starch on rumen fermentation, nutrient passage to the duodenum, and performance of cows; Cameron MR et al.; Four midlactation, multiparous Holstein cows fitted with ruminal and duodenal cannulas were used in a 4 x 4 Latin square design to determine the effects of supplementing urea or starch or both to diets containing fish meal on passage of nutrients to the small intestine and performance of lactating cows . The treatments (in a 2 x 2 factorial arrangement) were 1) control and control plus 2) urea, 3) starch, or 4) starch and urea . Supplementing diets with urea did not affect DMI; ruminal, postruminal, or total tract digestibilities of DM, starch, ADF, or NDF; ruminal fluid VFA concentrations or molar percentages; or ruminal fluid or particulate dilution rates . Feeding additional starch depressed DMI but did not alter ruminal or postruminal digestion of OM or VFA concentrations and molar percentages in ruminal fluid . Ruminal fluid ammonia concentration was increased by feeding urea and decreased by feeding additional starch . Passage of nonammonia N, nonammonia nonmicrobial N, or microbial N to the small intestine and efficiency of microbial CP synthesis were not affected significantly by supplying either urea or additional starch . Feeding urea increased passage of methionine to the small intestine, whereas feeding additional starch increased passage of methionine and arginine . Passage of other amino acids to the small intestine was not altered significantly by feeding urea or additional starch . Production of milk and milk protein was increased, but yields of fat and SNF were not altered by feeding diets supplemented with urea . Production of milk and milk fat was not affected, but yields of CP and SNF were decreased when additional starch was fed to cows.

J Anim Sci, 1991 Apr, 69(4), 1751 - 9
Fermentation characteristics and nutritional value of ruminal contents and blood ensiled with untreated or sodium hydroxide-treated wheat straw; el-Yassin FA et al.; Bovine ruminal contents and blood were ensiled with wheat straw, either untreated or treated with 4% NaOH (DM basis), with and without addition of 5% dry molasses . Proportions of ruminal contents, blood, and straw were 45:15:40, wet basis, respectively . Wheat straw also was ensiled alone, and water was added to attain 43% DM . After 60 d, all silages had a desirable aroma . The pH of the ensiled mixtures of ruminal contents, blood, and untreated straw was 4.43 and 4.56, with and without molasses, respectively . Values for silages containing treated straw, with and without molasses, were 5.95 and 7.37, respectively . All silages had substantial levels of lactic acid (2.4 to 4.9%, DM basis) . Addition of molasses increased (P less than .01) lactic acid concentrations . In a metabolism trial, 36 wethers were fed a 50% orchardgrass hay basal diet alone or supplemented with ensiled materials (1:1 ratio, DM basis) such that final diets had about 7 and 4% of their DM from ruminal contents and blood, respectively . Among the diets containing the ensiled mixtures, digestibilities of DM, OM, energy, NDF, ADF, cellulose, and hemicellulose were 6 to 20 percentage units higher (P less than .01) for silages containing treated vs untreated straw . Addition of molasses increased apparent digestibility only of CP and only in sheep fed ensiled mixtures with treated straw (interaction of straw treatment x molasses addition, P less than .05) . Nitrogen balance was increased (P less than .05) from 1.6 g/d to 2.9 g/d by NaOH treatment of straw . Metabolizable energy was higher (P less than .05) for diets containing silages with NaOH-treated straw.(ABSTRACT TRUNCATED AT 250 WORDS)

Nutr Rev, 1991 Apr, 49(4), 119 - 20
Fermentable fibers and vitamin B12 dependency; Decreased production of para-hydroxypenicillin V in penicillin V fermentations; Bristol-Myers Squibb Company, Industrial Division, Syracuse, NY 13221-4755Penicillin V (phenoxymethyl penicillin) is produced by industrial strains of Penicillium chrysogenum in the presence of phenoxyacetic acid (POAc), a side-chain precursor for the penicillin V molecule . The wild-type strain of P . chrysogenum produces an undesirable penicillin byproduct, para-hydroxypenicillin V (p-OH penicillin V), in addition to penicillin V, via para-hydroxylation of POAc and subsequent incorporation of the p-OH phenoxyacetic acid into the penicillin molecule . Most of the p-OH penicillin V is produced late in cycle when the POAc concentration in the medium is nearly depleted . The level of p-OH penicillin V produced by the control strain ranges up to 10-15% of the total penicillins produced . 3-Phenoxypropionic acid and p-bromophenylacetic acid partially inhibit the formation of p-OH penicillin V with a minimal effect on penicillin V productivity . Mutants deficient in their ability to hydroxylate POAc were found to produce lower levels of p-OH penicillin V . Multi-step mutation and screening, starting with the wild-type strain, have culminated in isolation of mutants which produce p-OH penicillin V as 1% of the total penicillins with no adverse effect on penicillin V productivity.

Int J Cancer, 1991 Mar 12, 47(5), 649 - 53
Combination of dietary factors in relation to breast-cancer occurrence; Van 't Veer P et al.; Combinations of dietary factors were studied in relation to breast-cancer occurrence among 133 breast cancer cases and 289 population controls in The Netherlands . Dietary factors were classified according to their possible mechanism of action, i.e., relating either to the intestinal microflora (total fat, fiber, fermented milk products) or to the anti-oxidant hypothesis (beta-carotene, selenium and polyunsaturated fatty acids) . From 6 interactions evaluated, the combination of high fiber intake and high intake of fermented milk products was the only one suggesting synergistic protection (age-and-fat-adjusted OR for interaction = 0.48, 95% confidence interval (CI) = 0.21 - 1.13) . In order to estimate the extent to which the above dietary factors together might be related to breast cancer, subjects with a supposedly favorable dietary pattern (low fat intake, high fiber intake, high intake of fermented milk products; high intake of beta-carotene and selenium, low intake of polyunsaturated fatty acids) were compared with subjects with an unfavorable dietary pattern . This resulted in an age-adjusted odds ratio of 0.40 (95% CI = 0.14 - 1.15), which was largely attributable to the combination of low intake of fat and high intake of fermented milk products and fiber (age-adjusted OR = 0.33, 95% CI = 0.15 - 0.73) . The other factors did not appreciably affect the odds ratio . These analyses show in a quantitative way that a dietary pattern which combines low intake of fat and high intake of fiber and fermented milk products might provide substantial protection against breast cancer.

J Dairy Sci, 1991 Mar, 74(3), 1026 - 37
Digestion of cell wall components by dairy heifers fed diets based on alfalfa and chemically treated oat hulls; Titgemeyer EC et al.; Four Holstein heifers were used in a 4 X 4 Latin square design to measure total tract digestion of cell wall components from diets based on alfalfa haylage and alkaline hydrogen peroxide-treated oat hulls . Diets contained 90% forage and 10% concentrate . Treatments were diets containing 90, 70, 50, or 30% alfalfa haylage with treated oat hulls supplying the remainder of the forage portion . Total tract digestion of cell wall-associated uronic acids, arabinose, galactose, mannose, rhamnose, and lignin were not affected by forage source . Digestibilities of cell wall glucose and xylose increased with increasing level of dietary treated oat hulls, reflecting the positive effect of alkaline hydrogen peroxide treatment on cell wall digestion . Cellulose (ADF minus acid detergent lignin) digestibilities were similar to those for cell wall glucose, whereas hemicellulose (NDF minus ADF) digestibilities were similar to those for cell wall arabinose plus xylose . Low digestibilities of alfalfa cell wall xylose indicate that some cell wall structure inhibits the degradation of alfalfa xylans . Low degradabilities of core lignin, esterified p-coumaric acid, and esterified acetyl groups suggest that these components may be involved primarily in depressing fermentation of cell wall polysaccharides.

Zentralbl Hyg Umweltmed, 1991 Mar, 191(2-3), 302 - 6
{Nutrition and individual defense--historical considerations}; Schadewaldt H; The first scientific understandings on the value of nutrition and the assimilation of food, in the Greek language "metabole" (metabolism), are published in the Corpus Hippocraticum . But the conception of metabolism was introduced in scientific literature not earlier than 1839 by Theodor Schwann (1810-1882) and 1842 by Justus von Liebig (1803-1873) . The antique ideas were completed in the 17th century by the theory of ferments, introduced by the iatro-chemist Johann Baptist van Helmont (1577-1644), and the Italian priest Lazzaro Spallanzani (1729-1799) could proof the existence of such processes in the living organism by animal experiments in 1776 . Then Schwann could discover in the gastric juice a substance in 1835 which he called "pepsin" . In the time of the voyages of discovery new, not yet known malnutritions on the ships were known as scurvy, beriberi and in the northern countries rickets . Then it became clear that not only the three groups of food, but also supplementary materials, known in 1912 as vitamines by Casimir Funk (1884-1967), could develop determined effects . The starvation in the first and the second world war showed clearly, that deterioration of food supply diminished the condition of immunity . Failed food experiments with gelatin, synthetically produced citric acid and the discussions of malnutrition diseases, based on a deficiency of zinc, of toddlers, are discussed as the malnutrition illness kwashiorkor in the third world . In conclusion a citation of the famous American physiologist Graham Lusk (1866-1932) is mentioned from the year 1906, who praised the scientific priority of the German medical researchPublication Types:

Historical Article

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