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