Vopr Pitan, 1992 Jan-Feb, (1), 63 - 7 {Chemical composition of a protein concentrate from Saccharomyces and its effect on immunologic response}; Iatskovskaia PIa et al.; The content of the main nutrients, as well as amino-acid, fatty-acid and mineral composition of a protein concentrate prepared from yeast-Saccharomyces grown in molasses were studied . It was found that the product contained a significant amount of protein, all essential amino acids, insignificant quantity of lipids in which saturated fatty acids prevailed . The concentrate ash was rich in calcium, phosphorus, magnesium, silicon, iron and other elements . The protein product included into experimental rations during a month produced no significant effect on the B-system immunity and did not induce sensitization. Folia Microbiol (Praha), 1992, 37(3), 193 - 8 Construction of a new Escherichia coli-Saccharomyces cerevisiae shuttle plasmid cloning vector allowing positive selection for cloned fragments; Puta F et al.; A new E . coli-S . cerevisiae shuttle plasmid cloning vector (pPW263) with a positive type of selection, was constructed . The selection system, based on the regulatory region of lambda phage controlling the expression of tetracycline resistance, was derived from the cloning vector pUN121 (Nilsson et al . 1983) . There are three cloning sites in the cI gene, EcoRI, HindIII and BglII, and, in addition, two unique sites in the neighborhood, BamHI and SalI . The size of the vector is 7.8 kb . The maintenance of the vector and the selection in yeast was ensured by the replication region of the 2 mu plasmid and by the URA3 marker gene, respectively. Folia Microbiol (Praha), 1992, 37(4), 289 - 94 The K3 type killer strains of genus Saccharomyces for wine production; Sulo P et al.; Using simultaneous fusion of protoplasts of three strains the auxotrophic K3 killer designated MH1 was prepared at a very low frequency and further employed for the transfer of the K3 killer character into a commercial wine yeast . A novel Saccharomyces Bratislava 1K3 strain with desirable technological and anti-yeast killer abilities was thus constructed . Attempts to prepare double K1/K3 killers were made . The obtained fusion products contained M1 dsRNA and were able to produce only the K1 type killer toxin. Dev Genet, 1992, 13(6), 485 - 97 Pulsed-field gel analysis of the pattern of DNA double-strand breaks in the Saccharomyces genome during meiosis; Game JC; Pulsed-field gel electrophoresis (PFGE) has been used to study the timing, frequency, and distribution of double-strand breaks (DSBs) in chromosomal-sized DNA during meiosis in yeast . It has previously been shown that DSBs are associated with some genetic hotspots during recombination, and it is important to know whether meiotic recombination events routinely initiate via DSBs . Two strains have been studied here--a high-sporulating homothallic wild type and a congenic mutant strain carrying a rad50S mutation . This mutant has previously been reported to accumulate broken molecules in meiosis to much higher frequencies than wild type and to abolish the characteristic wild-type processing of DNA that has been observed at the break sites . When whole chromosomes are resolved by PFGE, both strains show some broken molecules starting at the time that cells commit to genetic recombination . Breakage has been assessed primarily on Chromosome III and Chr . XV, using Southern hybridization to identify these chromosomes and their fragments . At any one time, break frequency in wild type is much lower than the cumulative frequency of recombination events that occur during meiosis . However, there is suggestive evidence that each break is short-lived, and it is therefore difficult to estimate the total number of breaks that may occur . In rad50S, chromosome breaks accumulate to much higher levels, which are probably broadly consistent with the estimated number of recombination events in wild type . However, since rad50S is substantially defective in completing recombination, it is not known for certain if it initiates events at wild-type frequencies . A surprising feature of the data is that a strong banding pattern is observed in the fragment distribution from broken chromosomes in both strains, implying that at least much of the breakage occurs at specific sites or within short regions . However, with the exception of the rDNA region on Chr . XII, assessment of the genetic map indicates that recombination can occur almost anywhere in the genome, although some regions are much hotter than others . Possible reasons for this apparent paradox are discussed . It may in part result from breakage levels too low for adequate detection in cold regions but may also imply that recombination events are localized more than previously realized . Alternatively, there may be a more indirect relationship between break sites and the associated recombination events. J Biol Chem, 1991 Nov 5, 266(31), 20720 - 4 The cloning and expression of a gene encoding Old Yellow Enzyme from Saccharomyces carlsbergensis; Saito K et al.; We have identified a gene that encodes Old Yellow Enzyme in brewer's bottom yeast . The open reading frame encodes a polypeptide of 400 amino acids with Mr = 45,021 . Using the T7 RNA polymerase system, recombinant enzyme was expressed in Escherichia coli . 17 mg of Old Yellow Enzyme was obtained from a 3-liter cell culture, and the recombinant enzyme had NADPH oxidase activity . On fast protein liquid chromatography separation, the recombinant enzyme showed a single large peak, while native enzyme from brewer's bottom yeast separated into five fractions on fast protein liquid chromatography . Southern blot analysis showed that there are at least two Old Yellow Enzyme genes in brewer's bottom yeast genomic DNA . These results suggest that the heterogeneity of Old Yellow Enzyme in Saccharomyces carlsbergensis is due to the presence of multiple genes. Genetika, 1991 Aug, 27(8), 1336 - 41 {Genetic activity of aminofluorene and 2-acetylaminofluorene in strains of Saccharomycetes under conditions of in vitro metabolic activation: influence of rad 1-5 mutation}; Pshenichnov MR et al.; It has been shown that the rad1-5 mutation which alters excision repair in Saccharomyces cerevisiae yeast increased reversion frequency of the ochre mutation his7-1 and the frequency of intragenic mitotic recombination in the LYS2 gene induced by 2-aminofluorene and 2-acetylaminofluorene, as compared with the wild type strains activated in vitro by 39 mix from chicken liver. J Bacteriol, 1991 Jul, 173(14), 4325 - 32 Cloning and characterization of LCB1, a Saccharomyces gene required for biosynthesis of the long-chain base component of sphingolipids; Buede R et al.; The existence of auxotrophic mutants of Saccharomyces cerevisiae having an absolute requirement for the long-chain base (lcb) component of sphingolipids suggests that sphingolipids are crucial for viability and growth . One mutant, termed the lcb1-1 mutant, lacks the activity of serine palmitoyltransferase, the first enzyme in the pathway for long-chain base synthesis . Here, we present evidence that LCB1 has been molecularly cloned . The size of the LCB1 transcript, the direction of transcription, and transcription initiation sites were determined . In addition, the coding region and its 5' and 3' flanking regions were sequenced . Analysis of the DNA sequence revealed a single open reading frame of 1,674 nucleotides, encoding a predicted peptide of 558 amino acids . The hydropathy profile of the predicted peptide suggests a hydrophobic, globular, membrane-associated protein with two potential transmembrane helices . Comparison of the predicted amino acid sequence to known protein sequences revealed homology to 5-aminolevulinic acid synthase and to 2-amino-3-ketobutyrate coenzyme A ligase . These homologies, the similarity of the chemical reactions catalyzed by the three enzymes, and the finding that LCB1 restores serine palmitoyltransferase activity to an lcb1-defective strain indicate that serine palmitoyltransferase or a subunit of the enzyme is the most likely product of LCB1 . Homology of the LCB1 predicted protein to the Escherichia coli biotin synthetase was also observed, but the biological significance of this observation is not clear . A role for sphingolipids in sporulation is implicated by our finding that diploids homozygous for lcb1 failed to sporulate. Chem Pharm Bull (Tokyo), 1991 Jul, 39(7), 1792 - 5 Metabolic fates of L-tryptophan in Saccharomyces uvarum (Saccharomyces carlsbergensis); Shin M et al.; The metabolism of L-tryptophan by Saccharomyces uvarum (carlsbergensis) was investigated by simultaneous measuring of fluxes through kynureninase, through transaminases and into protein using L-{methylene-14C} and L-{side chain-2,3-3H}tryptophan . In yeasts cultivated in synthetic medium (S medium), the flux into protein was predominant, closely followed by the flux leading to 2-3H liberation . The proportion of L-tryptophan metabolized via the latter flux increased over 10-fold (75% of total tryptophan metabolized) as the concentration of L-tryptophan was raised from 5 x 10(-5) to 5 x 10(-4) M . L-Tryptophan metabolized via the kynureninase flux was less than 5% of total tryptophan metabolized . In yeast extract-polypepton-glucose medium (YPG medium), more tryptophan was incorporated into protein than in the S medium . Contribution of the kynureninase flux remained very low . Tryptophan metabolism via each flux changed depending on the growth phase . 2-3H liberation was shown to be primarily due to tryptophol synthesis by high performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR), indole-3-acetic acid and kynurenic acid also contributing to 2-3H liberation but to a much lesser extent . 2-3H liberation increased dose-dependently at tryptophan concentration higher than 10(-5)M, while the kynureninase flux reached its plateau at 10(-5)M . Formation of tryptophol and indole-3-acetic acid via indole-3-pyruvic acid and indole-3-acetaldehyde with indole aldehyde as a by-product was confirmed using exogenous tryptophan metabolites with indole rings. Biochemistry, 1991 Jun 4, 30(22), 5546 - 55 Laser flash photolysis studies of the kinetics of electron-transfer reactions of Saccharomyces flavocytochrome b2: evidence for conformational gating of intramolecular electron transfer induced by pyruvate binding; Walker MC et al.; The kinetics of reduction of the flavocytochrome from Saccharomyces cerevisiae by exogenous deazaflavin semiquinones have been investigated by using laser flash photolysis . Direct reduction by deazaflavin semiquinone of both the b2 heme and the FMN cofactor occurred via second-order kinetics with similar rate constants (9 x 10(8) M-1 s-1) . A slower, monoexponential, phase of FMN reoxidation was also observed, concurrent with a slow phase of heme reduction . The latter accounted for approximately 20-25% of the total heme absorbance change . Both of these slow phases were protein concentration dependent, yielding identical second-order rate constants (1.1 x 10(7) M-1 s-1), and were interpreted as resulting from intermolecular electron transfer from the FMN semiquinone on one protein molecule to an oxidized heme on a second molecule . Consistent with this conclusion, no slow phase of heme reduction was observed with deflavo-flavocytochrome b2 . Upon the addition of pyruvate (but not D-lactate or oxalate), the second-order rate constant for heme reduction was unaffected, but direct reduction of the FMN cofactor was no longer observed . Reduction of the heme cofactor was followed by a slower partial reoxidation, which occurred concomitantly with a monoexponential phase of FMN reduction . Both processes were protein concentration independent and were interpreted as the result of intramolecular electron transfer from reduced b2 heme to oxidized FMN . Potentiometric titrations of the flavocytochrome in the absence and presence of pyruvate demonstrated that the thermodynamic driving force for electron transfer from FMN to heme is much greater in the absence of pyruvate . Despite this, intramolecular electron transfer was only observed in the presence of pyruvate . This result is interpreted in terms of a conformational change induced by pyruvate binding which permits electron transfer between the cofactors . The rate constant for intramolecular electron transfer in the presence of pyruvate was dependent on ionic strength, suggesting the occurrence of electrostatic effects which influence this process. J Nutr Sci Vitaminol (Tokyo), 1991 Jun, 37(3), 269 - 83 Metabolism of tryptophan to niacin in Saccharomyces uvarum; Shin M et al.; In Saccharomyces uvarum, the effect of metabolic intermediates of the tryptophan-NAD pathway on the niacin-production was investigated . Exogenously added kynurenine and 3-hydroxyanthranilic acid raised the content of total niacin of the cells 2-fold as compared to the control cells, although anthranilic acid and tryptophan were less effective . Tryptophan was taken up into the cells faster than kynurenine, and the intracellular pool of tryptophan was larger than that of kynurenine . Of kynurenine (0.05 mM) added to the medium, 55% went through the transaminase flux (2-H liberation), 20% through the kynureninase flux, but none through the acetyl-CoA flux . As for tryptophan, only 2% went through the kynureninase flux . The products through the transaminase flux were identified as kynurenic acid (85%) and xanthurenic acid . 3-Hydroxykynurenine, 3-hydroxyanthranilic acid, quinolinic acid and niacin were also detected . The metabolism of tryptophan via the kynureninase flux reached a plateau above 0.05 mM . The production of kynurenine and kynurenic acid gradually increased above 0.05 mM . Tryptophol was formed in parallel with the amount of tryptophan consumed, while the rate of niacin production increased after glucose and tryptophan were exhausted . Based on the data obtained, a possible regulatory mechanism of the tryptophan-NAD pathway was discussed. Gene, 1991 Apr, 100, 95 - 103 Primary structure and regulation of a glucoamylase-encoding gene (STA2) in Saccharomyces diastaticus; Lambrechts MG et al.; We have determined the complete nucleotide (nt) sequence of a 5070-bp DNA fragment containing a glucoamylase-encoding gene (STA2) from Saccharomyces diastaticus . The 5' transcription start points for STA1, STA2 and STA3 were determined by primer extension of their respective mRNAs using reverse transcriptase . The sequence data show one major open reading frame (ORF) of 767 amino acids encoding GAII with a calculated Mr of 82,514 . The 5' region in the ORF contains two ATG sequences within 30 nt of each other . The upstream region of STA2 was amplified by the polymerase chain reaction (PCR) and fused to the Escherichia coli lacZ gene . Some of the PCR products contained mutations in ATG1 and/or ATG2 . Results indicated that both ATG1 and ATG2 encode functional translation start codons, but ATG2 was shown to encode the stronger initiator . The upstream region of STA2 contains a canonical sequence that is homologous to known sites of repression by the MATa/MAT alpha-encoded repressor . Also, consensus RAP1 (Repressor-Activator Protein 1)-binding sites are located in the 5' upstream region and within the coding region of STA2. FEMS Microbiol Lett, 1991 Feb, 62(1), 17 - 20 Effects of exogenous hemin on the niacin content of aerobically grown Saccharomyces uvarum; Shin M et al.; In Saccharomyces uvarum aerobically grown in the tryptophan-added medium, the niacin content started to increase when both tryptophan and glucose in the medium had almost been exhausted . In the kynurenine-added medium, the niacin production occurred immediately after incubation started . Hemin added to the medium enhanced total niacin production by increasing the amount of tryptophan metabolized via the kynureninase flux . The results suggest that the niacin biosynthesis from tryptophan was regulated by catabolite repression, which was alleviated by exogenously added hemin. Proc Natl Acad Sci U S A, 1990 Oct, 87(20), 7824 - 8 Cation-selective channels in the vacuolar membrane of Saccharomyces: dependence on calcium, redox state, and voltage; Bertl A et al.; The vacuolar membrane of the yeast Saccharomyces cerevisiae, which is proposed as a system for functional expression of membrane proteins, was examined by patch-clamp techniques . Its most conspicuous feature, in the absence of energizing substrates, is a cation channel with a characteristic conductance of approximately 120 pS for symmetric 100 mM KCl solutions and with little selectivity between K+ and Na+ (PNa+/PK+ approximately 1) but strong selectivity for cations over anions (PCl-/PK+ less than 0.1) . Channel gating is voltage-dependent; open probability, Po, reaches maximum (approximately 0.7) at a transmembrane voltage of -80 mV (cytoplasmic surface negative) and declines at both more negative and more positive voltages (i.e., to 0 around +80 mV) . The time-averaged current-voltage curve shows strong rectification, with negative currents (positive charges flowing from vacuolar side to cytoplasmic side) much larger than positive currents . The open probability also depends strongly on cytoplasmic Ca2+ concentration but, for ordinary recording conditions, is high only at unphysiologically high (greater than or equal to 1 mM) Ca2+ . However, reducing agents such as dithiothreitol and 2-mercaptoethanol poise the channels so that they can be activated by micromolar cytoplasmic Ca2+ . The channels are blocked irreversibly by chloramine T, which is known to oxidize exposed methionine and cysteine residues specifically. Mol Gen Genet, 1990 Sep, 223(2), 288 - 96 The apocytochrome b gene of Chlamydomonas smithii contains a mobile intron related to both Saccharomyces and Neurospora introns; Colleaux L et al.; The mitochondrial DNA of the two interfertile algal species Chlamydomonas smithii and Chlamydomonas reinhardtii are co-linear with the exception of ca . 1 kb insertion (the alpha insert) present in C . smithii DNA only . In vegetative diploids resulting from interspecific crosses, mitochondrial genomes are transmitted biparentally except for the alpha insert which is transmitted to all C . reinhardtii molecules in a manner reminiscent of the intron-mediated conversion event that occurs at the omega locus in yeast mitochondria, under the action of the I-SceI endonuclease . Here we report that the alpha insert corresponds to a typical group I intron of 1075 bp, inserted within the gene for apocytochrome b and containing a 237 codon open reading frame (ORF) . We also report the complete sequence of the apocytochrome b gene of C . smithii . Comparison with the sequence of the same gene in C . reinhardtii reveals the precise intron insertion site . These data, together with the previous genetic data provide the first example of intron mobility in mitochondria of the plant kingdom . The product of the intronic ORF shows 36% amino acid identity with the I-SceI endonuclease whereas the intron ribozyme shows a 60% identity at the nucleotide level with the Neurospora crassa cob.1 intron . The possibility of a recent horizontal transfer of introns between fungi and algae is discussed. Mol Cell Biol, 1990 Aug, 10(8), 4415 - 9 Sequencing of Saccharomyces telomeres cloned using T4 DNA polymerase reveals two domains; Wang SS et al.; By using T4 DNA polymerase rather than S1 or Bal31 nuclease to clone yeast telomeres, very little telomeric DNA is lost . These clones were used to determine the DNA sequence of virtually the entire telomeric tract . Our results demonstrated that a slightly modified version, C2-3A(CA)1-6, of the consensus derived from sequence analysis of more-internal regions (J . Shampay, J . W . Szostak, and E . H . Blackburn, Nature {London} 310:154-157, 1984) extends to the very end of the chromosome . The sequence analysis also suggests that yeast telomeres consist of two domains: the proximal 120 to 150 base pairs, which appear to be protected from processes such as recombination, degradation, and elongation, and the distal portion of the telomere, which is more susceptible to these events. Genetika, 1990 Jul, 26(7), 1169 - 77 {Genetic analysis of spontaneous and 6-N-hydroxylaminopurine and propiolactone induced Adp+ mutants in Saccharomyces yeasts}; Noskov VN et al.; 652 spontaneous and 6-N-hydroxylaminopurine and propiolactone-induced mutants were obtained in yeast . 598 of them were LYS2 mutants . Detailed genetic analysis of the mutants was performed, including analysis of growth pattern on lysineless medium, suppressibility by nonsense suppressors of three types and localization on the recombination map of the LYS2 gene . Mutants induced by different agents were different for all these criteria, except for distribution among the map regions. Genetika, 1990 Jul, 26(7), 1161 - 8 {Development of a system of intragenic mapping for molecular genetic analysis of mutations in the gene LYS2 of Saccharomyces yeasts}; Noskov VN et al.; The collection of overlapping lys2 deletions (five in the chromosomal and seven in the plasmid LYS2 gene) is constructed in this work . The deletions overlap the whole coding region of the gene and provide the system for intragenic recombinational mapping of lys2 mutations in one of 14 controlled regions . A portion of these regions can be correlated with the regions on the physical map of LYS2 . Mutations in two regions can be easily cloned . The system constructed gives the possibility for the study of intragenic and molecular specificity of mutagenesis. Yeast, 1990 Jul-Aug, 6(4), 311 - 8 Increase of the anion and proton permeability of Saccharomyces carlsbergensis plasmalemma by n-alcohols as a possible cause of its de-energization; Petrov VV et al.; The effect of n-alcohols on ATP-dependent generation of delta pH and Em across the plasma membrane vesicles of the yeast Saccharomyces carlsbergensis was investigated . The alcohols were shown to collapse delta pH and Em in the order C2 less than C3 less than C4 less than C5 less than or equal to C6 greater than or equal to C7 greater than C8 greater than C11, the dissipation of Em being more pronounced . Inhibition of the plasmalemma H(+)-ATPase was insignificant; at low alcohol concentrations its activity even increased . The basic reason for the toxic effect of the alcohols on the yeast cells was suggested to be due to the increase in the anion and proton permeability of the plasma membrane . Mg2+ partially prevented the increase in the plasmalemma ion permeability by the alcohols investigated. Gut, 1990 Jun, 31(6), 714 - 6 Protracted enteric cryptosporidial infection in selective immunoglobulin A and saccharomyces opsonin deficiencies; Jacyna MR et al.; Chronic cryptosporidial infection in man usually occurs in those who are immunocompromised . We report a patient with a one year history of bowel symptoms resulting from persistent cryptosporidial infection of the colon . Investigations showed underlying selective IgA and saccharomyces opsonin deficiencies but no evidence of cell mediated immune dysfunction . Both selective immunoglobulin A and opsonin deficiencies are relatively common in the general population and may be a cause of susceptibility to persistent cryptosporidial infection. Genetics, 1990 May, 125(1), 13 - 20 Cloning by gene amplification of two loci conferring multiple drug resistance in Saccharomyces; Leppert G et al.; Yeast DNA fragments that confer multiple drug resistance when amplified were isolated . Cells containing a yeast genomic library cloned in the high copy autonomously replicating vector, YEp24, were plated on medium containing cycloheximide . Five out of 100 cycloheximide-resistant colonies were cross-resistant to the unrelated inhibitor, sulfometuron methyl, due to a plasmid-borne resistance determinant . The plasmids isolated from these resistant clones contained two nonoverlapping regions in the yeast genome now designated PDR4 and PDR5 (for pleiotropic drug resistant) . PDR4 was mapped to chromosome XIII, 31.5 cM from LYS7 and 9 cM from the centromere . PDR4 was mapped to chromosome XV between ADE2 and H1S3 . Genetic analysis demonstrated that at least three tightly linked genes (PDR5, PDR2 and SMR3) that mediate resistance to inhibitors are located in this region . Insertion mutations in the either PDR4 or PDR5 genes are not lethal, but the insertion in PDR5 results in a drug-hypersensitive phenotype. Arch Biochem Biophys, 1990 Mar, 277(2), 434 - 8 Anomerization and hydrolysis of lactose by beta-galactosidase from Saccharomyces lactis; Mbuyi-Kalala A et al.; Beta-Galactosidase from Saccharomyces lactis was found to be able to catalyze both the anomerization of alpha-lactose and the hydrolysis of beta-lactose; the rate of hydrolysis appeared to be four times higher with a 1:1 mixture of alpha and beta lactose than with a freshly prepared solution of alpha-lactose . The enzyme was also found to be unable to hydrolyze alpha-lactose . Thus, it appears that beta-galactosidase from S . lactis has its hydrolytic activity on lactose adapted only to the naturally more abundant beta-lactose. Arch Latinoam Nutr, 1990 Mar, 40(1), 95 - 106 {Effect of dietary concentration of Saccharomyces carlsbergensis yeast recovered from beer, in Warren male chicks}; Poo ME et al.; Six groups of 1-day-old Warren chicks (seven per group) were fed for 15 days on diets with the protein supplement made of mixtures of soybean protein and dried yeast Saccharomyces carlsbergensis recovered from beer . The purpose was to establish the maximum substitution level of the soybean protein isolate by dried yeast, with the least possible related metabolic effects . Each group was fed one of the diets containing 0%, 25%, 50%, 75% and 100% of the protein supplement based on yeast protein, substituting the soybean protein isolate . In order to estimate the NPR value of the yeast protein, a group which received a protein-free diet, was also included . Protein utilization and changes in both plasma and liver total lipids, triglycerides, cholesterol and liver and kidney uric acid, were determined . In triglycerides, cholesterol and liver and kidney uric acid, were determined . In the groups fed diets with 75% and 100% of yeast protein, decreased body weight gain and PER and NPR values were observed, as well as an increment in the liver and kidney uric acid concentrations, although the diet consumption was not substantially modified . Thus, protein utilization, measured as PER and NPR, was lower in these groups . Plasma uric acid was not modified in neither group . The plasma lipids were not altered at whatever yeast concentration, while in the liver, total lipids as well as triglycerides decreased when the dietary yeast was increased . Results indicated that when using whole yeast cells recovered from beer in pre-starting rations for chicks, 50% of yeast protein is the maximum substitution level. Ann Parasitol Hum Comp, 1990, 65(2), 51 - 60 {Effects of Saccharomyces boulardii yeast on trophozoites of Entamoeba histolytica in vitro and in cecal amebiasis in young rats}; Rigothier MC et al.; Lyophilized and rehydrated Saccharomyces boulardii yeasts were administered to young rats previously inoculated into the cecum with Entamoeba histolytica . The numbers of diseased young rats and the severity of the infection, assessed from the appearance of the cecum and its content of mucus and amebae, were significantly reduced by the treatment . The lesions observed resembled those seen in the untreated controls, although healing was faster in the treated animals . Saccharomyces boulardii had no intrinsic amebicidal action in vitro. Free Radic Biol Med, 1990, 9(1), 39 - 50 Pharmacogenetics of cyclic guanylate, antioxidants, and antioxidant enzymes in Saccharomyces; Munkres KD; Supplements of antioxidants, superoxide dismutase (SOD), catalase, cyclic guanylate (cGMP), and theophylline, or omission of iron and copper from the medium are therapeutic for the inferior growth and viability of yeast mutants doubly deficient in mitochondrial and exocellular SOD isozymes under oxidative stresses . Cyclic adenylate tends to be ineffective or counterproductive . Oxy-stress resistant revertants are cross-resistant to other oxy-stresses and acquire one, the other, or both isozymes . The principal conclusions are: i) a genetic defect in cGMP metabolism probably compromises regulation of the enzymes' synthesis; ii) the enzymes are only essential for growth and viability under oxidative stresses; iii) oxidative toxicity is mediated by both exo- and endocellular oxy-radicals, particularly hydroxyl radicals; and iv) the pharmacogenetic features and the mutants' phenotypes are quite similar to those of negative antioxidant enzyme regulatory mutants of the related ascomycete Neurospora. Biochem Int, 1990, 21(4), 695 - 704 On the determination of trehalose-6-phosphate synthase in Saccharomyces; Panek AC et al.; Trehalose-6-phosphate synthase activity was determined by colorimetric, spectrophotometric and trehalose specific assays . All methods gave comparable results thus confirming our previous findings (1) and those reported by Elander (2) . Different strains and mutants of Saccharomyces were carefully re-investigated in relation with the recent claim made by Vandercammen et al . (3) that our spectrophotometric assay over-estimated the enzyme activity and that no differences exist between wild type and mutant strains . In this paper we also confirm the de-activation of the trehalose synthase complex in response to a "glucose signal", and present trehalose-6-phosphate synthase and trehalase activities in different strains measured during all phases of growth on glucose. Plasmid, 1990 Jan, 23(1), 67 - 70 Cloning of industrial Saccharomyces 2-microns plasmid variants by in vivo site-specific recombination; Xiao W et al.; Southern analyses defined several industrial Saccharomyces yeast strains with extensive 2-microns DNA polymorphism . Variants included insertions and deletions up to several hundred base pairs . To facilitate the investigation of yeast plasmid evolution we developed a novel method of cloning 2-microns plasmids by taking advantage of 2-microns circle in vivo site-specific recombination and an SMRI gene as a dominant selectable marker . This method can be applied to other organisms for the isolation of plasmid variants and provides a new approach to in vivo plasmid construction. Genetics, 1989 Dec, 123(4), 725 - 38 The genetic control of direct-repeat recombination in Saccharomyces: the effect of rad52 and rad1 on mitotic recombination at GAL10, a transcriptionally regulated gene; Thomas BJ et al.; We have previously shown direct-repeat recombination events leading to loss of a plasmid integrated at the GAL10 locus in Saccharomyces cerevisiae are stimulated by transcription of the region . We have examined the role of two recombination- and repair-defective mutations, rad1 and rad52, on direct repeat recombination in transcriptionally active and inactive sequences . We show that the RAD52 gene is required for transcription-stimulated recombination events leading to loss of the integrated plasmid . Similarly, Gal+ events between the duplicated repeats that retain the integrated plasmid DNA (Gal+ Ura+ replacement events) are reduced 20-fold in the rad52 mutant in sequences that are constitutively expressed . In contrast, in sequences that are not expressed, the rad52 mutation reduces plasmid loss events by only twofold and Gal+ Ura+ replacements by fourfold . We also observe an increase in disome-associated plasmid loss events in the rad52 mutant, indicative of chromosome gain . This event is not affected by expression of the region . Plasmid loss events in rad1 mutant strains are reduced only twofold in transcriptionally active sequences and are not affected in sequences that are repressed . However, the rad1 and rad52 double mutant shows a decrease in plasmid loss events greater than the sum of the decreases in the rates of this event displayed by either single mutant in both constitutive and repressed DNA, indicating a synergistic interaction between these two genes . The synergism is limited to recombination since the rad1 rad52 double mutant is no more sensitive when compared with either single mutant in its ability to survive radiation damage . Finally, the recombination pathway that remains in the double mutant is positively affected by transcription of the region. Antonie Van Leeuwenhoek, 1989 Oct, 56(3), 233 - 9 Debaryomyces udenii, sp . nov . (Saccharomycetaceae), a new species from soil; Van der Walt JP et al.; A new, soil-associated species of the genus Debaryomyces, D . udenii, is described . The species is characterized by pusticulate rather than verrucate ascospores, and slowly lytic asci. Ukr Biokhim Zh, 1989 Sep-Oct, 61(5), 34 - 42 {Physico-chemical properties of thiamine kinase from Saccharomyces carlsbergensis yeasts}; Chernikevich IP et al.; The amino acid composition and intrinsic fluorescence were studied in thiamine kinase (ES 2.7.6.2) of brewer's yeast . The enzyme molecule is characterized by higher concentrations of amino acids which promote alpha-helix formation of the protein globule, the amount of residues (cysteine, proline) either binding or folding polypeptide chains being considerably high . Amino acids of middle and low hydrophobicities were the most frequent among the amino acid residues with nonpolar R-groups . The value for the protein isoelectric point was 6.21 . The eigen pH value and isoionic point were in good agreement with the isoelectric point value and amounted to 6.28 . The fluorescence spectrum has a maximum at 328 nm, half-width at 53 nm and a quantum yield at 0.14 nm . The tryptophane residues were located in hydrophobic surroundings, unexposed to anion quenchers and almost unexposed to cation ones . The fluorescence and phosphofluorescence parameters were sensitive to the conformational changes in the molecule . At pH of 5-9 the protein conformation remained unchanged . The temperature rise above 40 degrees C resulted in a disturbance in the nativity of the globule . The elevation of the enzyme concentration from 0.05 to 1 mg/ml increased the polarization degree from 0.115 to 0.194, the quantum yield and the spectrum position remaining unchanged . The results obtained develop knowledge of the equilibrium system of oligomerous forms of thiamine kinase with different catalytic properties. Genetika, 1989 Aug, 25(8), 1364 - 72 {A new type of antagonistic activity of Saccharomycetes yeasts and its mode of inheritance}; Zekhnov AM et al.; New type of killer activity of Saccharomyces cerevisiae was found . About 40% of this yeast strains tested formed growth inhibition zones on the lawn of the sensitive yeast Pachysolen tannophilus (Boldin et Adzet) BKM y-274 . As shown by crossing these killers with non-killers and the tetrad analysis of hybrids obtained, 2 killer: 2 non-killer segregation took place, indicating the chromosomal mode of inheritance of the character . Mutants with weak expression of this killer activity were obtained after treating with 5-fluorouracil and cycloheximide. Curr Genet, 1989 Aug, 16(2), 81 - 7 Identification of an ADPG-dependent trehalose synthase in Saccharomyces; Paschoalin VM et al.; Uridine diphosphoglucose is not the sole donor for trehalose synthesis in yeast cells: an ADPG-dependent trehalose synthase, has been identified in mutant strains with undetectable UDPG-dependent trehalose-6-P synthase activity . Genetic and chromatographic studies indicate that the two activities correspond to different proteins . The apparent Km for the nucleotide is similar for both enzymes, and Mg2+ is also required for both activities; however, a striking difference was observed with respect to ATP.Mg activation . This newly determined enzymatic activity in Saccharomyces clarifies previous contradictory results with mutant strains that are able to accumulate trehalose during growth yet whose UDPG-dependent trehalose synthase activity is undetectable in vitro. Gene, 1989 Jul 15, 79(2), 189 - 97 Primary structure of the maltose-permease-encoding gene of Saccharomyces carlsbergensis; Yao B et al.; The MAL6 locus of Saccharomyces consists of a cluster of at least three genes: MAL6R encodes a positively acting regulatory protein; MAL6S encodes maltase; and MAL6T encodes maltose permease . A MAL6 Eco RI fragment, E1, that encompasses most of the MAL6T gene except for the first 90 bp of the ORF at its 5' end (sequenced previously), was cloned into a pGEM-Blue vector . Sequential deletions were generated and then sequenced . The MAL6T gene has a putative ORF of 1845 bp . The amino acid composition and sequence of the deduced protein shows that it is highly hydrophobic and has a size of 68.2 kDa . Computer-generated hydropathy profiles suggest that the MAL6T protein may have up to nine membrane-spanning regions . Generation of functional fusions of the MAL6T promoter region to Escherichia coli lacZ-containing vectors indicates that sequences in the intergenic region are responsible for the induction of MAL6T by maltose and for its carbon catabolite repression . We also demonstrated the suitability of E . coli lacZ as a reporter gene for promoter activity studies in yeast. Mikrobiologiia, 1989 Jul-Aug, 58(4), 566 - 70 {Activity of endopolygalacturonase in culture fluid of experimentally prepared polyploid cultures of Saccharomyces vini}; Imshenetskii AA et al.; The action of colchicine solutions on a diploid Saccharomyces vini culture used in viniculture yielded three polyploid strains . The strains differ from the parent culture in their cell morphology and a higher endopolygalacturonase activity. Genetics, 1989 Jun, 122(2), 307 - 16 Molecular evolution of the telomere-associated MAL loci of Saccharomyces; Charron MJ et al.; The MAL gene family of Saccharomyces consists of five multigene complexes (MAL1, MAL2, MAL3, MAL4, and MAL6) each of which encodes maltose permease (GENE 1), maltase (GENE 2) and the trans-acting MAL-activator (GENE 3) . Four of these loci have been mapped and each is located at or near the telomere of a different chromosome . We compare the physical structure of the MAL loci and their flanking sequences . The MAL loci were shown to be both structurally and functionally homologous throughout an approximately 9.0-kb region . The orientation of the MAL loci was determined to be: CENTROMERE . . . GENE 3-GENE 1-GENE 2 . . . TELOMERE . Telomere-adjacent sequences were found flanking GENE 2 of the MAL1, MAL3 and MAL6 loci . No common repeated elements were found on the centromere-proximal side of all the MAL1, loci . These results suggest that, during the evolution of this polygenic family, the MAL loci translocated to different chromosomes via a mechanism that involved the rearrangement(s) of chromosome termini. Dtsch Tierarztl Wochenschr, 1989 May, 96(6), 313 - 6 {In vitro parameters for understanding the immunocompetence of chickens of different lineage . 1 . The cytotoxicity of avian whole blood against Saccharomyces cells}; Kahl D et al.; A cytotoxicity test was performed as a parameter for the nonspecific defense capacity in chickens using blood and saccharomyces cells (SCT) . The test has the special merit of frequent repetitions of the results by two parallel test arrangements . The results of individual animals were not altered during a period of 14 days, as well as relatively not being affected by actual day fluctuation as long as environmental changes or antigenic changes do not appear . The cytotoxic activity is due to cellular defense mechanisms, especially concerning the activity of granulocytes, thrombocytes and monocytes but not lymphocytes and erythrocytes . The lysozyme contents of plasma show a very space cytotoxic activity against saccharomyces cells. Mol Gen Genet, 1989 May, 217(1), 60 - 9 Structure of the multigene family of MAL loci in Saccharomyces; Chow TH et al.; Multigene families are a ubiquitous feature of eukaryotes; however, their presence in Saccharomyces is more limited . The MAL multigene family is comprised of five unlinked loci, MAL1, MAL2, MAL3, MAL4 and MAL6, any one of which is sufficient for yeast to metabolize maltose . A cloned MAL6 locus was used as a probe to facilitate the cloning of the other four functional loci as well as two partially active alleles of MAL1 . Each locus could be characterized as a cluster of three genes, MALR (regulatory), MALT (maltose transport or permease) and MALS (structural or maltase), encoded by a total of about 7 kb of DNA; however, homologous sequences at each locus extend beyond the coding regions . Our results indicate that there is extensive homology among the MAL loci, especially within their maltase genes . The greatest sequence diversity occurs in their regulatory gene regions . Southern cross analyses of the cloned MAL loci indicate a single duplication of the MAL6R-homologous sequences upstream of the MAL6R gene as well as an extensive duplication of more than 10 kb at the MAL3 locus . The large repeat at the MAL3 locus results in the presence of four copies of MAL3R-homologous sequences and two copies of MAL3T-homologous sequences at that locus . Two naturally occurring inactive alleles of MAL1 show a deletion or divergence of their MALR sequences . The significance of these repeats in the evolution of the MAL multigene family is discussed. Genetika, 1989 May, 25(5), 819 - 28 {detection of products of reverse transcription in Saccharomyces cells}; Ratovitskii EA; Poly(A)-RNA-DNA hybrids complementary to retrotransposons Ty1 have been isolated from baker yeast cells . DNA and RNA in these complexes are represented by perfect hybrids . Reverse transcription enzymatic activity was identified in yeast cells . The results are consistent with the model of reverse transcriptional replication and transposition of Ty elements, similar to that of retroviruses. Genetika, 1989 Mar, 25(3), 425 - 37 {Modification changes of the genetic material in Saccharomyces yeasts}; Repnevskaia MV et al.; The problem of mating-type switches in heterothallic yeast cells was investigated . In selective system for cytoduction in alpha x alpha crosses alpha-cytoductants were predominantly obtained . Thus matings in alpha x alpha crosses can proceed through non-heritable changes (modifications) of the mating type alpha----a . The frequency of alpha-cytoductants after UV-irradiation of the recipient cells exceeded the control value 50-90 times . The extra copy of MAT alpha dramatically decreased the frequency of cytoductants in alpha x alpha crosses, either spontaneously or after UV-irradiation . The rad18 recipient defective in postreplication repair had 70-times increased level of mating-type modifications, as compared with isogenic Rad+ strain . An explanation consistent with these data is that mating-type modifications are due to phenotypic expression of primary lesions of MAT alpha locus . Such lesions might be expressed as transient a-mating type . After the mating event, these lesions can be repaired or turned to true mutations within the MAT locus . In fact, approximately half of non-mating cytoductants from alpha x alpha crosses had the phenotype of mat alpha 2 mutants. Acta Cient Venez, 1989, 40(1), 40 - 5 Production of intracellular alpha-glucosidase in brewery waste by Saccharomyces carlsbergenesis; Windevoxhel M et al.; Saccharomyces carlsbergensis strain ATCC 9080 was grown on acid hydrolyzed brewery waste . The substrate contains 22 mg/ml of total carbohydrates of which approximately 60% represents reducing sugars such as maltose and glucose . Optimal conditions for substrate hydrolysis were 1.5% w/v sulfuric acid, 20 minutes and temperature of 110 degrees C . Maximum enzyme production was obtained in a medium containing 0.05% w/v yeast extract at 35 degrees C and at an initial pH of 6 . Addition of nitrogen sources was unnecessary . Optimal conditions for alpha-glucosidase extraction from yeast included pH 7.5, 30 degrees C, and 10 minutes of sonication . Maximum hydrolysis of PNPG occurred at pH 7.5, temperature between 30 degrees C and 25 minutes of incubation . Michaelis-Menten constants and Vmax were 1 mM, 0.56 mol/min/mg of protein on P-nitrophenly-alpha-D-glucophyra-noside and 5 mV, 5 mol/min/mg of protein on maltose respectively. Genome, 1989, 31(2), 497 - 502 Phenotypic expression of primary lesions of genetic material in Saccharomyces yeasts; Inge-Vechtomov SG et al.; "Illegitimate" mating of yeasts (alpha x alpha), either spontaneous or induced by uv light or ethyl methanesulfanate, in a selective system for "cytoduction" revealed that about 95% of cytoductants expressed their original (alpha) mating type . Inducing the mating by treating the recipient of cytoplasm with uv light reached two orders of magnitude . An additional copy of MAT alpha in the alpha recipient almost completely eliminated the effect, which means that nonheritable mating type changes observed are formally recessive and are localized within MAT alpha complex . About 1% of cytoductants obtained were nonmating types and some of them were identified as mat alpha l mutants . Radl8 mutant as a recipient showed a considerably elevated spontaneous frequency of illegitimate hybridization and cytoduction . The cytoductants also preserved the original mating type . These facts suggest that nonheritable changes of mating type are due to repairable primary (premutational) lesions in MAT alpha genetic material . The significance of these results for understanding the mechanism of nonheritable variability is discussed. Curr Genet, 1989 Jan, 15(1), 7 - 16 Ethanol inhibition of Saccharomyces and Candida enzymes; Martin-Rendon E et al.; Ethanol inhibition of several hydrolases (sucrase, maltase, trehalase, melezitase and cellobiase) has been measured in both highly ethanol-tolerant Saccharomyces strains (R) and in Candida strains less tolerant to ethanol (S) . Cells were either grown in the presence of ethanol and the activities of the enzymes measured without preincubation in this alcohol ("in situ" inhibition assay), or the culture was grown in the absence of ethanol and the activities of the enzymes were determined after preincubation and in the presence of this compound ("in vitro" inhibition assay) . Ethanol inhibition (Ki values) of sucrase, maltase, trehalase, and melezitase was quite different for these different enzymes in the same strain (R or S), but similar for the same enzyme in different strains (R and S) . The Ki values for cellobiase, which is absent from the R strain, were higher when induced than at the basal level and higher in in vitro assays than in in situ assays . This suggests that the inhibition observed in situ is mainly the result of an inhibition of other proteins related to cellobiase (i.e., those involved in its synthesis) but not a direct inactivation of the enzyme by ethanol . Accordingly, when hybrids between Saccharomyces (R) and Candida (S) strains were constructed by protoplast fusion, and cellobiase was measured in the parental Candida strain and some of the hybrids, there was an increase in the Ki values in the in situ assays from 2.25% ethanol in Candida to 5.5% in some of the hybrids. Eur J Biochem, 1988 Dec 15, 178(2), 437 - 43 Separation and characterization of four enzyme forms of beta-galactosidase from Saccharomyces lactis; Mbuyi-Kalala A et al.; beta-Galactosidase from Saccharomyces lactis has been purified to serve as a model for the kinetic behavior of human lactase in adult lactase deficiency . Enzymes from both species are neutral and follow Michaelis-Menten kinetics . beta-Galactosidase of S . lactis is more readily available than the human lactase . An enzyme preparation from S . lactis (Maxilact 40,000), which is used commercially to hydrolyze lactose in milk, has been found to contain four isozymes of beta-galactosidase . Methods have been developed for the separation and purification of each of the four enzymes . The enzymes were found to differ in molecular mass, kinetic behavior, isoelectric point, response to pH, specific volume and sensitivity to metal ions . The four enzymes had apparent molecular masses of 630 kDa, 550 kDa, 41 kDa and 19 kDa . Their specificity constants (kcat/Km) were found to be 42.0, 355.2, 0.38 and 0.48 mM-1 s-1, respectively . The techniques of reiterated ultrafiltration used for the isolation of these isozymes may be applicable to other purification processes. Can J Microbiol, 1988 Nov, 34(11), 1230 - 4 Preliminary ESR study of Mn(II) retention by the yeast Saccharomyces; Kihn JC et al.; Manganese(II) retention by yeast cells was investigated in the absence of any energy source in the medium . Only a small fraction of the cations retained (2.7 to 9%) was bound by the cell wall; the binding sites were negatively charged groups like phosphodiesters in the phosphomannan and carboxylates in the proteins . ESR spectra of the cations, which entered the cell, indicated that they could be complexed by polyelectrolytes or precipitated with orthophosphate to form MnHPO4(crystal) . In both cases, the concentration of free Mn2+ remained low . The entry of cations was thus driven by the concentration gradient, and no metabolic energy was therefore required in our experimental conditions. Genetika, 1988 Oct, 24(10), 1761 - 7 {Genetic analysis of mitochondrial rho-mutability in Saccharomyces yeasts . VI . Quantitative characteristics of the effect of mutation srm5 on the mitochondrial stability of natural and recombinant genetic structures}; Koltovaia NA et al.; The srm5 mutation diminishes the spontaneous rho- mutation rate by an order of magnitude . Frequency of rho- mutations is 500 times lower in homozygous cultures, as compared with those of normal SRM+/SRM+ diploids . The rate of spontaneous loss of extra chromosome IV is about 25 times higher in srm5 disomes, as compared with SRM+ ones . Haploid srm1 srm5 transformants loose recombinant circular minichromosomes spontaneously about 4 times more frequently than srm1SRM5 cells . The data presented suggest that general control of mitotic stability of different (mitochondrial and nuclear, nuclear as well as recombinant) genetic structures operates in Sacch . cerevisiae . Autonomously replicating sequences (ARS elements) seem to be involved in this mechanism. Genetika, 1988 Oct, 24(10), 1752 - 60 {Mutability of LYS2 gene in diploid Saccharomyces yeasts . II . Frequency of mutants induced by 6-N-hydroxylaminopurine and propiolactone}; Pavlov IuI et al.; Chemical mutagens 6-N-hydroxylaminopurine (HAP) and propiolactone (PRO) induce Lys2 mutants with high frequency in diploid yeast Saccharomyces cerevisiae . HAP induces such mutants even in tetraploid strains . The genetic analysis of mutants was performed . It is shown that PRO induces mutants by means of "mutation-mitotic segregation" mechanism, while HAP induces mutants through novel mechanism "both allele mutation" . Manifestation of such mechanism is the null fertility after meiosis of diploid mutants induced by HAP. Genetika, 1988 Sep, 24(9), 1586 - 92 {Genetic analysis of mitochondrial rho-mutability in Saccharomyces yeasts . V . Isolation and mapping of nuclear mutation srm5, which simultaneously reduces the rho-mutability and mitotic stability of chromosomes}; Prosvirova TIu et al.; A nuclear UV-induced srm5 mutation has been isolated which leads to pronounced decrease in spontaneous rho- mutability . Also, this mutation renders yeast n+1 disomes significantly less stable and changes the cell shape . The srm5 mutation has been mapped in the right arm of chromosome II at 10.3 cM from the tyr1 towards the centromere. Genetika, 1988 Jul, 24(7), 1159 - 65 {Selective systems for obtaining recessive ribosomal suppressors in saccharomycete yeasts}; Inge-Vechtomov SG et al.; Recessive mutations only occurring in two genes (ribosomal suppressors sup1 and sup2) can be obtained using special selective system . We demonstrate that the absolute selectivity of the system is based on selection for simultaneous reversions to prototrophy in mutants requiring adenine and histidine in haploids marked by two different nonsense mutations--his7-1 (UAA) and ade1-14 (UGA, this being identified in the present study) . In support to this conclusion, we developed an analogous system utilising his7-1 (UAA) and lys2-87 (UGA) . The selectivity of the system is shown to be influenced both by the choice of nonsense alleles and by genotypic background. Genetics, 1988 Jul, 119(3), 541 - 7 Coincident recombination during mitosis in saccharomyces: distance-dependent and -independent components; Golin JE et al.; In mitosis, coincident recombination events between widely separated markers occur more frequently than expected for two independent acts . Several different mechanisms have been proposed to account for this phenomenon . It has been argued that coincident recombination could be due to either an extensive region of heteroduplex DNA or some other distance-dependent mechanism . Alternately, it has been suggested that at least some is due to subpopulations of cells which undergo recombination at very high frequencies . The purpose of these experiments is to evaluate the possible contribution of distance-dependent and distance-independent components . By comparing the coincident recombination frequencies for markers on the same homolog as well as pairs of unlinked sites, we show that there is a strong distance-dependent component for at least 8.8-35-kbp, depending on the type of recombination event (conversion or intrachromosomal exchange) . For larger distances separating sites, a distance-independent mechanism(s) results in higher than expected frequencies. Mol Gen Genet, 1988 Jul, 213(1), 56 - 62 Primary structure of the regulatory gene from the MAL6 locus of Saccharomyces carlsbergensis; Sollitti P et al.; We determined the complete nucleotide sequence of the yeast MAL6R gene from the Saccharomyces carlsbergensis MAL6 locus . The MAL6R gene encodes a transacting protein required for the inducible, coordinate expression of the two divergently transcribed structural genes, MAL6T (maltose permease), and MAL6S (maltase) at this locus . The transcription initiation sites for MAL6R were determined by primer extension experiments . The MAL6R gene contains an open reading frame of 473 amino acids with a calculated Mr of 54,892 . The N-terminus of the deduced protein contains an amino acid sequence isologous to a consensus sequence for cysteine-zinc associated DNA binding fingers found in other fungal DNA binding proteins . The MAL6R gene was mapped to chromosome VIII by using OFAGE (orthagonal field alternating gel electrophoresis) gels and hybridization with specific chromosome and MAL6 probes. Biochem J, 1988 May 1, 251(3), 931 - 3 Expression of human liver epoxide hydrolase in Saccharomyces pombe; Jackson MR et al.; Human liver microsomal epoxide hydrolase cDNA was inserted into the yeast expression vector pEVP11 . The resulting recombinant plasmid was introduced into Saccharomyces pombe . The epoxide hydrolase protein and enzymic activity was subsequently expressed and identified in the 105,000 g pellet after centrifugal fractionation of homogenized yeast cells . This method will provide a useful source of human liver epoxide hydrolase, avoiding the problems of obtaining human tissue. Appl Environ Microbiol, 1988 Apr, 54(4), 966 - 71 High-efficiency, one-step starch utilization by transformed Saccharomyces cells which secrete both yeast glucoamylase and mouse alpha-amylase; Kim K et al.; Transformed, hybrid Saccharomyces strains capable of simultaneous secretion of glucoamylase and alpha-amylase have been produced . These strains could carry out direct, one-step assimilation of starch, with conversion efficiency greater than 93% during a 5-day growth period . One of the transformants converted 92.8% of available starch into reducing sugars in only 2 days . Glucoamylase secretion by these strains resulted from expression of one or more chromosomal STA genes derived from Saccharomyces diastaticus . The strains were transformed by a plasmid (pMS12) containing mouse salivary alpha-amylase cDNA in an expression vector containing yeast alcohol dehydrogenase promoter and a segment of yeast 2 micron plasmid . The major starch hydrolysis product produced by crude amylases found in culture broths was glucose, indicating that alpha-amylase and glucoamylase acted cooperatively. Biochem J, 1988 Apr 1, 251(1), 115 - 9 The intrinsic as opposed to the apparent stoichiometry of the glycine-proton symport of the yeast Saccharomyces carlsbergensis; Eddy AA et al.; 1 . Various ways of computing the proton stoichiometry of glycine absorption were examined in relation to the problem of distinguishing the proton flow (i) through the symport from the basal proton flow (ii) outside it . By depolarizing the plasma membrane, i will tend to inhibit ii . 2 . A series of 23 yeast (Saccharomyces carlsbergensis) preparations grown with proline or glutamate were used, some of which were starved in the presence of glucose . Consequently, after ATP depletion, the rate of glycine uptake from a 0.2 mM solution varied through the series from 3 to 14 nmol.min-1.mg-1 . Basal proton uptake in the absence of glycine was fairly constant at 3-4 nmol.min-1.mg-1 . 3 . After addition of glycine, the number of extra equivalents of protons entering the yeast with each amino acid equivalent in 30 s was 0.5 at the lowest rate of glycine absorption and 1.8 equivalents at the fastest rate . However, total proton absorption in 30 s increased in direct proportion to the amount of glycine absorbed . The proportionality factor, indicative of the carrier stoichiometry, was 2.25 +/- 0.13 (23) S.E.M . The effective basal proton uptake was negligibly small . 4 . Progress of proton and glycine absorption by each yeast preparation in the period up to 180 s fitted the mathematical model described in the preceding paper by Eddy, Hopkins & Johnson {(1988) Biochem . J . 251, 111-114} . The analysis led to two estimates of the constant ratio of the inflow of protons to the inflow of glycine that would apply when the basal proton flow vanished . These further estimates of the carrier stoichiometry were also near 2, being 2.07 +/- 0.24 (6) and 2.22 +/- 0.07 (17). Proc Natl Acad Sci U S A, 1988 Jan, 85(2), 349 - 53 Cell-cell recognition in yeast: isolation of intact alpha-agglutinin from Saccharomyces kluyveri; Lasky RD et al.; The heat-labile sexual agglutinin from Saccharomyces kluyveri strain 17 (alpha-agglutinin) has been isolated in an apparently intact form from wild-type and mnn1 (glycosylation-defective) cells . The wild-type agglutinin is polydisperse, due to variable degrees of glycosylation, and migrates on native gels with an apparent mass of greater than 400 kDa, whereas under denaturing conditions it appears somewhat smaller . The mnn1 agglutinin is also heterogeneous but has a lower molecular mass due to the presence of shorter N- and O-linked polymannose chains . Both agglutinins are converted sequentially by proteolysis to active fragments of approximately equal to 150 and 60 kDa, but the rate of proteolysis of the more highly glycosylated wild-type agglutinin is much slower than that of the mnn1 agglutinin . The 60-kDa fragment was isolated by HPLC and found to contain 46% carbohydrate as mannose, all of which was linked to serine and threonine . Thus, the N-linked oligosaccharides are restricted to that part of the agglutinin molecule that presumably anchors the agglutinin in the cell wall. J Basic Microbiol, 1988, 28(3), 197 - 208 Replication and recombination in gene establishment in non-Saccharomyces yeasts; Oliver SG; A brief review is given on the establishment of recombinant DNA technology for non-conventional yeasts . The availability of DNA delivery systems, selectable markers for identification of transformants, and the means of replicating and amplifying the recombinant DNA are discussed . Some of the existing transformation systems among non-conventional yeasts are explained. Genetika, 1987 Dec, 23(12), 2148 - 56 {Chromosome stability in saccharomycete yeasts}; Karpova TS et al.; Mutants with high instability of chromosome III designated Chl+ (chromosome loss) were obtained after irradiation with UV the Z4221-3c1 haploid disomic for chromosome III . The Chl+ mutants can be divided into two classes: 1) CL2, CL3, CL7, CL9, CL11, CL12, CL13 with elevated level of spontaneous inter- and intragenic recombination; 2) CL4, CL8 which unstable maintenance of chromosome III not accompanied with elevation of mitotic recombination frequency . The CL4 and CL8 mutants also reveal, in contrast to other mutants, unstable maintenance of artificial mini-chromosomes with chromosomal replicator ARS1 and centromeric loci CEN3, CEN4, CEN5, CEN6, CEN11 . Substitution of ARS1 for other yeast replicators (ARS2, ARS of 2 micron plasmid) leads to no stabilization of mini-chromosomes in mutants . The noncentromeric plasmids containing homologous replicator (or replicators) from Candida maltosa are maintained with the same frequency both in wild type and in mutants . So, the stability of mini-chromosomes in CL4 and CL8 is not connected with uneffective replication of these chromosomes . Instability of chromosome III and mini-chromosomes in CL4 and CL8 is controlled by two nonallelic genes designated chl14 and chl18 . We suppose that these genes control the process of centromere interaction with mitotic spindle microtubules. Mol Biol (Mosk), 1987 Nov-Dec, 21(6), 1467 - 79 {A 2-um plasmid of Saccharomyces}; Soidla TR et al.; The review of yeast endogenous 2 micron plasmid and of some 2 micron plasmid based vectors is devoted to structure--function relationships with a particular emphasis on the stable replication control mechanisms . Some original data on possible novel plasmid encoded proteins are provided. J Biol Chem, 1987 Jul 25, 262(21), 10146 - 53 The mitochondrial reading frame RF3 is a functional gene in Saccharomyces uvarum; Seraphin B et al.; The yeast mitochondrial genome contains three reading frames, RF1, RF2, and RF3, which are related to the group I maturases, though they are not intronic sequences . In the Saccharomyces cerevisiae strain D273-10B/A, these reading frames are interrupted by G + C-rich sequences (GC clusters) which break the frames . In the present work we described a Saccharomyces uvarum strain which possesses a RF3 continuous sequence devoid of GC clusters . Moreover, our results strongly suggest that in the same strain RF2 and RF1 are also continuous sequences . As all three RFs belong to transcription units which are highly expressed, it is most reasonable to assume that RF1, RF2, and RF3 are functional genes . Furthermore, we have discovered a rule which seems to explain the transposition of GC clusters, considered as mobile elements, in the mitochondrial genome. Ecotoxicol Environ Saf, 1987 Feb, 13(1), 7 - 12 The effect of pentachlorophenol and its metabolite tetrachlorohydroquinone on RNA, protein, and ribosome synthesis in Saccharomyces cells; Ehrlich W et al.; The effect of pentachlorophenol (PCP) and its metabolite tetrachlorohydroquinone (TCH) were tested on growth, RNA, protein and ribosome syntheses, and ribosome content in yeast cells . Cells exposed to increasing concentrations of PCP show increasing inhibition to RNA and ribosome synthesis, and to cell growth . TCH causes a delay of the growth of the cell culture (prolongation of the lag phase) but does not cause inhibition . After treatment with TCH the maximum of the RNA synthesis was retarded, but subsequently reached nearly the same level as the untreated control cells . On ribosome synthesis and ribosome content, treatment with increasing concentrations of PCP, as well as of TCH, leads to a substantial decrease in ribosomal synthesis and, finally, total inhibition . Parallel to this, the content of free and membrane-bound ribosomes is diminished . PCP exhibits a stronger effect than TCH . The protein synthesis is only slightly reduced after treatment with PCP or TCH (with concentrations up to 20 micrograms/ml). Acta Microbiol Hung, 1987, 34(3-4), 255 - 7 Effect of organic volatiles from Saccharomyces on the spore germination of fungi; Saksena N et al.; Common volatile organic compounds (acetaldehyde, ethylacetate, ethanol, n-propanol, isobutanol, 2-methyl-butanol, 3-methyl butanol) tested singly and in combination inhibited the spore (conidium) germination of Helminthosporium oryzae, Cercospora personata, Cunnighamella blakesleeana, Colletotrichum capsici, and Alternaria solani. Curr Genet, 1987, 11(6-7), 459 - 65 Regulation of the trehalose-6-phosphate synthase complex in Saccharomyces . I . Interconversion of forms by phosphorylation; Panek AC et al.; Trehalose-6-phosphate synthase is another example of an enzyme of carbohydrate metabolism, in Saccharomyces, which could be regulated by interconversion of forms . Deactivation was mediated both in vivo and in vitro by a cyclic AMP-dependent protein kinase . Reversibility of this process was obtained by a phosphatase treatment leading to an increase in activity . The phosphorylated, less active form of the enzyme proved to be more susceptible to activation by ATP.Mg . Mutants with well defined lesions in the cyclic AMP-dependent protein kinase system were used to corroborate our findings of a possible regulatory mechanism of trehalose-6-phosphate synthase activity by interconversion of forms. J Biol Chem, 1986 Dec 5, 261(34), 16174 - 9 Cell-cell recognition in yeast . Molecular nature of the sexual agglutinin from Saccharomyces kluyveri 17-cells; Weinstock K et al.; A previous study of Saccharomyces kluyveri 17-cell sexual agglutinin (alpha-agglutinin), solubilized by zymolyase (beta-glucanase) digestion of 17-cells and purified by affinity adsorption to immobilized 16-cell agglutinin (alpha-agglutinin), suggested that the major active component was a glycoprotein of 60,000 daltons and that a minor active component of 40,000 daltons was also present, possibly the result of proteolysis (Pierce, M., and Ballou, C . E . (1983) J . Biol . Chem . 258, 3576-3582) . We now show that both of these active components are proteolytic fragments of a larger form with a molecular weight of 134,000, and that the latter is produced by proteolysis of a still larger species with a molecular weight of more than 200,000 . Washed 17-cell wall fragments were labeled with 125I and digested with purified protease-free beta-1,3-glucanase, and the solubilized alpha-agglutinin was precipitated with antiserum raised against purified agglutinin containing a mixture of the 60,000- and 134,000-dalton forms . Gel electrophoresis in sodium dodecyl sulfate revealed a radioactive material with Mr greater than 200,000 that, on digestion with zymolyase containing an active protease, was converted sequentially to radioactive components with Mr = 134,000, 60,000, and 40,000. Genetika, 1986 Dec, 22(12), 2768 - 74 {Genetic analysis of mitochondrial rho-mutability in Saccharomyces . III . Comparative analysis of the effect of various nuclear srm mutations and disomy for chromosome IV on rho-mutagenesis}; Devin AB et al.; Different combinations of modifying genes which enhance the rho- mutability of haploid yeast cells are shown to be suppressible by the srm1, srm2, srm3 mutations and by the disomy for chromosome IV . The srm1 mutation leads to dramatic decrease in both the spontaneous and ethidium-bromide induced rho- mutability . Other srm mutations studied and the disomy appear to cause relatively moderate quantitative changes in the spontaneous rho- mutation rate and to have no significant effect on mutation induction by ethidium bromide . Neither additivity nor synergism was revealed by the analysis of the interaction between the srm mutations . We suggest that in Saccharomyces an efficient mechanism of the rho- mutagenesis operates which can be directly affected by the srm1 mutation and more or less modified by other srm mutations under study and by the disomy for chromosome IV. Tsitol Genet, 1986 Nov-Dec, 20(6), 428 - 32 {The use of the polyene-resistant mutation model in Saccharomyces as a test-system for detecting genetically active substances}; Kvasha VV et al.; The simple test-system has been developed to register mutagenic activity of different chemicals using a model of forward polyene-resistant mutations in Saccharomyces cerevisiae. Genetika, 1986 Nov, 22(11), 2625 - 36 {Hybridization of cells of the same mating type in Saccharomyces yeasts}; Inge-Vechtomov SG et al.; The problem of mating-type switches in heterothallic yeast cells was investigated . 93% of non-mating hybrids were obtained in a X a crosses . The hybrids obtained in alpha X alpha crosses expressed alpha-mating type predominantly . Hybrids with no major rearrangements or loss of chromosome III were detected among these hybrids . In the selective system for cytoduction in a X a crosses the significant part of all cytoductants were alpha-maters, i.e . those originated through a----alpha switches . In alpha X alpha crosses alpha cytoductants were predominantly obtained either spontaneously or after UV-irradiation, though the frequency of cytoductants after UV-irradiation exceeded the control value several times . So, we developed the method for selection of mating-type "switchers" (a in equilibrium alpha), avoiding the diploid stage, and demonstrated the possibility of hybridization among the alpha-cells without hereditary changes at the MAT locus. Genetika, 1986 Oct, 22(10), 2408 - 15 {Genetic analysis of the mitochondrial rho-mutability in Saccharomyces . II . Disomy for chromosome IV and spontaneous rho-mutability}; Devin AB et al.; The disomy for chromosome IV in the strains studied led to: reduction in the red pigmentation of ade1 mutant colonies; a decrease in spontaneous rho- mutant frequency, and impairment of sporulation in hybrids descended from disomic parents . The nuclear srm1 mutation decreasing the spontaneous rho- mutability promoted the spontaneous extra chromosome loss in the disomics for chromosome IV . This result suggests a close connection between the spontaneous rho- mutability and mitotic chromosome stability. Genetika, 1986 Sep, 22(9), 2244 - 51 {Genetic analysis of mitochondrial rho-mutability in Saccharomyces . I . Polygenic determination of spontaneous rho-mutability: gene-modifiers and srm mutation}; Devin AB et al.; The phenotypic trait "starry colony" in Saccharomyces is associated with a high spontaneous rho- petite mutability . Genetic analysis of this trait has shown the high rho- mutability to be caused by several modifying genes present together in the cell genome . Every single modifying gene only produces a relatively small enhancement in the rho- mutability . Mutations in four nuclear srm (spontaneous rho- mutability) loci were isolated after mutagenic treatment of highly rho- mutable haploid cells . In contrast to the modifying genes, each of these mutations has a pronounced effect on the spontaneous rho- mutability, causing significant decrease in it. Arch Biochem Biophys, 1986 Jul, 248(1), 138 - 50 Biochemical and immunological characterization of the STA2-encoded extracellular glucoamylase from saccharomyces diastaticus; Modena D et al.; In Saccharomyces diastaticus each one of three unlinked genes (STA1, STA2, STA3) encodes a glucoamylase (alpha-1,4 glucanglucohydrolase, EC 3.2.1.3) that allows yeast to grow on starch . The enzyme encoded by the STA2 gene (glucoamylase II) has been purified from culture medium to near homogeneity by ethanol precipitation, Trisacryl M DEAE chromatography, and HPLC gel filtration . Glucoamylase II consists of two identical subunits whose average size is 300 kDa . Under denaturing conditions, the native dimeric enzyme readily dissociates to a monomer . Enzymatic deglycosylation of denatured enzyme gives rise to intermediate, partially glycosylated forms and to a 56-kDa completely deglycosylated protein . Glucoamylase releases glucose units by cleaving alpha-1,4 bonds from the nonreducing end of different oligosaccharides, but has only a barely detectable alpha-1,6 hydrolyzing activity . The pH optimum for the purified enzyme was found to be 5.1 . The enzyme has a greater affinity for maltohexaose (Km = 0.98 mM, V/Km = 2.39) than for maltotriose (Km = 2.38, V/Km = 0.68) or maltose (Km = 3.20, V/Km = 0.39) . Both polyclonal and monoclonal antibodies have been raised against glucoamylase II . The polyclonal antibodies specifically inhibit yeast glucoamylase II activity in a dose-dependent manner, but are found to immunoblot other yeast glycoproteins as well . This oligosaccharide-specific reaction can be competed out by adding excess mannan without affecting glucoamylase reactivity . The cross-reactivity of the polyclonal antibodies with other amylolytic enzymes correlates well with evolutionary distance . Evidence is presented that monoclonal antibodies specific for either carbohydrate or protein epitopes have been obtained. J Biol Chem, 1986 Apr 5, 261(10), 4519 - 24 UDP-glucose 4-epimerase from Saccharomyces fragilis . Presence of an essential arginine residue at the substrate-binding site of the enzyme; Mukherji S et al.; UDP-glucose 4-epimerase from Saccharomyces fragilis was inactivated by the arginine-specific reagents phenylglyoxal, 1,2-cyclohexanedione, and 2,3-butanedione following pseudo first order reaction kinetics . The reaction order with respect to phenylglyoxal was 1.8 and that with respect to the other two diones was close to unity . Protection afforded by substrate and competitive inhibitors against inactivation by phenylglyoxal and the reduced interaction of 1-anilinonaphthalene 8-sulfonic acid, a fluorescent probe for the substrate-binding region after phenylglyoxal modification, suggested the presence of an essential arginine residue at the substrate-binding region . Experiments with {7-14C}phenylglyoxal in the presence of UMP, a ligand known to interact at the substrate-binding region, showed that only the arginine residue at the active site could be modified by phenylglyoxal . The characteristic coenzyme fluorescence of the yeast enzyme was found to be enhanced three times in phenylglyoxal-inactivated enzyme suggesting the incorporation of the phenyl ring near the pyridine moiety of NAD. Mol Gen Genet, 1986 Apr, 203(1), 29 - 35 Molecular cloning and characterization of the STA2 glucoamylase gene of Saccharomyces diastaticus; Pretorius IS et al.; The Saccharomyces diastaticus structural gene STA2, encoding an exracellular glucoamylase (1,4-alpha-D-glucan glycohydrolase, EC 3.2.1.3.), has been cloned by complementation of a stao strain . A genomic library was initially constructed from a STA2 yeast strain in the yeast Escherichia coli shuttle cosmid vector pYCl . The Sta+ complementing function was further delimited to an 8.3 kb BglII fragment whose restriction map was found to be similar to related genomic regions of STA1 and STA3 . Fusions of several DNA fragments derived from the 8.3 kb BglII fragment with a truncated E . coli beta-galactosidase gene resulted in two overlapping fragments that could direct the production of large fusion proteins in E . coli . These fusion proteins were immunoprecipitable by anti-glucoamylase II antibodies, confirming that the Sta+ complementing fusion was due to the expression of a gene that coded for a yeast glucoamylase . Measurements of the STA1, STA2 and STA3 RNA transcripts by RNA-DNA hybridization using an internal fragment of the cloned STA2 gene as the probe indicated that a common transcript of 2.5 kb is produced by each of the STA genes . Integrative disruption of the STA2 gene through homologous recombination was achieved by transforming a STA2 yeast strain to Sta- using an in vitro constructed donor DNA fragment that has the URA3 gene inserted within the coding region of the cloned glucoamylase gene . This was confirmed by tetrad analysis of crosses between strains carrying a disrupted STA2 and a functional STA2 . Southern blot analysis using BamHI digested genomic DNA from 15 tetrads demonstrated consistent co-segregation and Mendelian inheritance of the Sta- phenotype with STA2::URA3 . These data further confirm that the cloned DNA that showed Sta+ complementing activity carries a functional STA2 gene that encodes the yeast extracellular glucoamylase II. Radiat Environ Biophys, 1986, 25(2), 81 - 91 Radiation induced formation of giant cells in Saccharomyces uvarum . IV . Macromolecular synthesis and protein patterns; Rink H et al.; X-irradiated (1.0 kGy) yeast cells (Saccharomyces uvarum, ATCC 9080), grown in liquid medium stop their mitotic activities and form giant cells by development of several buds which do not separate from mother cells . Depending on the time in culture, wet and dry weights per cell, protein-RNA- and DNA- contents per cell as well as incorporation rates of 14C-leucine per cell and per hour and patterns (isoelectric focussing) of water soluble proteins were studied . Weights per cell, RNA and protein contents per cell and 14C-leucine incorporation rates increase markedly in giant cells, whereas DNA content per cell is only duplicated . Protein patterns in isoelectric focusing show one interesting difference . In samples from giant cells one protein band (IP = 6.63) decreases after 8 h in culture and later on disappears completely . This finding is not due to primary damage in X-irradiated DNA but seems to be related to the control of cell cycle events. Int J Immunopharmacol, 1986, 8(3), 245 - 59 Immunopharmacological effects of Saccharomyces boulardii in healthy human volunteers; Caetano JA et al.; Investigation of oral administration of Saccharomyces boulardii in healthy volunteers demonstrates several cellular and humoral changes in peripheral blood . Among its effects are the increase of erythrocytes, leucocytes, polymorphs, neutrophils, complement components C3, C5, C3d, serum anticomplementary activity and leucocyte chemokinesis, specially when autologous serum and antigen have been added to the culture medium and decrease of complement haemolytic activity (CH50, classic and alternative pathways) . We have also demonstrated that in vitro S . boulardii was able to activate complement directly, to fix C3b to its surface and that its phagocytosis by mononuclear cells was complement-dependent . The overall changes in serum proteins suggested changes of acute phase proteins typical of an inflammatory process . Furthermore S . boulardii had no mitogenic response of lymphocyte populations . Our results demonstrated that S . boulardii activates the reticuloendothelial system and complement system and suggest that S . boulardii merits therapeutic trial in a variety of clinical situations. Radiat Environ Biophys, 1986, 25(1), 23 - 30 Radiation induced formation of giant cells in Saccharomyces uvarum . III: Effect of X-rays on nuclear division; Baumstark-Khan C et al.; Spindle formation and nuclear division of budding and irradiated yeast cells (Saccharomyces uvarum) was investigated by fluorescence microscopy of protoplasted cells . Protoplasts were treated with antitubulin antibodies and DAPI, a fluorescent dye staining DNA . In budding yeast cells, duplication of spindle pole bodies as well as formation of complete 1-micron spindles and elongated 8-micron spindles were documented . In X-irradiated cells, spindle pole bodies were duplicated as well, forming the complete 1-micron spindle . Nuclei of giant cells have lost the elongation ability and remain in a "normal" G2-phase state, thus preventing nuclear as well as cellular division. Radiat Environ Biophys, 1986, 25(1), 55 - 63 Inactivation of Saccharomyces cells by 8-methoxypsoralen plus pulsed laser irradiation in the wavelength range 308 nm-380 nm; Tuszynski W et al.; Two different strains of Saccharomyces cerevisiae, one diploid wild type and one haploid mutant deficient in excision repair were irradiated with laser pulses in the range 308 nm to 380 nm after 8-MOP treatment . Both the shoulder (Dq) and the final slope (Do) of the inactivation curves were dependent on wavelength which showed a broad minimum around 355 nm . No differences in inactivation were recorded after pulsed irradiations between the repetition rates of 5 Hz and 35 Hz . Irradiations with pulses of the energy density from 0.1 mJ/cm2 up to 26 mJ/cm2 resulted in a final slope increasing with pulse energy density . This was in contrast to the effects of irradiation alone. Gene, 1986, 41(1), 75 - 84 Primary structure of the maltase gene of the MAL6 locus of Saccharomyces carlsbergensis; Hong SH et al.; We have determined the complete nucleotide (nt) sequence of a 2937-bp DNA fragment containing the yeast maltase (EC 3.2.1.20) gene (MAL6S) as well as part of the contiguous maltose permease gene (MAL6T) from the MAL6 locus of Saccharomyces carlsbergensis . The MAL6S gene encodes an alpha-glucosidase that is required for the utilization of maltose as a carbon source by yeast . The 5' transcription initiation sites for both MAL6S and MAL6T were determined by primer extension experiments using reverse transcriptase . The sequence data show one major open reading frame (ORF) of 584 amino acids (aa) for maltase with a calculated Mr of 68 107, somewhat larger than the value of 63 000 previously determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) analysis . The nucleotide sequences upstream of both the MAL6S and MAL6T genes, which are divergently transcribed, show common structural features for the transcription initiation of yeast genes as well as signals required for their translation . The codon bias index shows that the MAL6S gene is moderately expressed . The possible significance of two 17-bp dyad symmetric sequences, found in the intergenic region of MAL6S and MAL6T, for the control of expression of these genes is also discussed. Curr Genet, 1986, 10(10), 725 - 31 Further evidence for the alternative pathway of trehalose synthesis linked to maltose utilization in Saccharomyces; Paschoalin VM et al.; Yeast strains bearing a deficiency in trehalose-6-phosphate synthase activity are unable to accumulate trehalose on any carbon source unless they contain one of the MAL genes . If the gene is inducible then synthesis of trehalose occurs specifically during growth on maltose: when the MAL gene is constitutive then trehalose accumulation can also be seen when cells are grown on glucose . Different systems for trehalose synthesis were suggested: one of them would require the UDPG-linked trehalose synthase whereas the second would utilize an alternative pathway . We proposed a mechanism by which the gene-product of a MAL gene would serve as a common positive regulator for the expression of the genes coding for maltose permease, alpha-glucosidase and some component of the trehalose accumulation system . In order to elucidate this novel pathway a strain lacking UDPG-linked trehalose synthase activity and harboring a defect in maltose uptake was constructed . Excessive maltose uptake resulted in accumulation of intracellular maltose, and twice as much trehalose as in a control strain . Partial inhibition of hexokinase by xylose affected the ratio between internal maltose and trehalose and significantly reduced glycogen synthesis . Sodium fluoride also blocked glycogen synthesis but allowed for trehalose accumulation . Moreover, a mutant which lacks hexokinase I and II was unable to accumulate trehalose when grown on glucose in spite of the presence of a constitutive MAL2 gene . These results suggest that trehalose synthesis would require G-6-P formation derived from maltose . Such a deviation would allow for slowing down the glycolytic flux which, in turn, would favour efficient maltose utilization.(ABSTRACT TRUNCATED AT 250 WORDS) FEBS Lett, 1985 Nov 18, 192(2), 303 - 6 H+/ion antiport as the principal mechanism of transport systems in the vacuolar membrane of the yeast Saccharomyces carlsbergensis; Okorokov LA et al.; The secondary transport systems of the yeast vacuolar membrane have been investigated by the method of radioactive isotopes {( 14C}arginine); activation of H+-ATPase by cations (Cat+), when the enzyme is under H+ control and measurement of changes in the proton gradient (delta pH) and membrane potential (Em) due to the supposed substrates of the transporters . The main mechanism of cation transport across the yeast tonoplast is probably H+/Cat+ antiport . The apparent Km of antiporters for Ca2+, Mg2+, Mn2+, Zn2+ and Pi are 0.06, 0.3, 0.8, 0.055-0.17 and 1.5 mM, respectively. Genetika, 1985 Nov, 21(11), 1794 - 8 {Comparative genetics of yeasts . XXIII . Unusual inheritance of toxin formation in Saccharomyces paradoxus batschinskaia}; Naumov GI; The data about cytoplasmic control of toxin formation in Saccharomyces paradoxus CBS5829 are presented . A novel determinant (KIL-k3) is probably located in the mitochondrial genome . In other mutations, adenine deficiency results in suppression of toxin formation of the K3 type . A new killer plasmid (KIL-kx) was detected in Sacch . paradoxus VKM Y-2472. Mol Cell Biol, 1985 Nov, 5(11), 2894 - 902 Evolution of the dispersed SUC gene family of Saccharomyces by rearrangements of chromosome telomeres; Carlson M et al.; The SUC gene family of Saccharomyces contains six structural genes for invertase (SUC1 through SUC5 and SUC7) which are located on different chromosomes . Most yeast strains do not carry all six SUC genes and instead carry natural negative (suc0) alleles at some or all SUC loci . We determined the physical structures of SUC and suc0 loci . Except for SUC2, which is an unusual member of the family, all of the SUC genes are located very close to telomeres and are flanked by homologous sequences . On the centromere-proximal side of the gene, the conserved region contains X sequences, which are sequences found adjacent to telomeres (C . S . M . Chan and B.-K . Tye, Cell 33:563-573, 1983) . On the other side of the gene, the homology includes about 4 kilobases of flanking sequence and then extends into a Y' element, which is an element often found distal to the X sequence at telomeres (Chan and Tye, Cell 33:563-573, 1983) . Thus, these SUC genes and flanking sequences are embedded in telomere-adjacent sequences . Chromosomes carrying suc0 alleles (except suc20) lack SUC structural genes and portions of the conserved flanking sequences . The results indicate that the dispersal of SUC genes to different chromosomes occurred by rearrangements of chromosome telomeres. Genetika, 1985 Apr, 21(4), 564 - 73 {Mutability of the LYS2 gene in diploid saccharomycete yeasts . I . The occurrence of spontaneous mutants and mutants induced by x-ray and ultraviolet radiation}; Chernov IuO et al.; More than 3000 spontaneous and induced lys2 mutants were obtained in haploid and diploid strains of yeast Saccharomyces . The ability to utilize alpha-aminoadipate was used for lys2 mutant screening . The spontaneous and induced mutation rates were measured in haploid and diploid strains . Mitotic segregation of pho1 marker linked to LYS2 was studied in lys2 mutants obtained in diploid strains . Fertility of diploid lys2 mutants was tested . The conclusion to be drawn from the data presented is that mutations appeared in one of two homologous chromosomes and then segregated by mitotic homozygotization. Radiat Environ Biophys, 1985, 24(1), 9 - 16 Radiation induced formation of giant cells in Saccharomyces uvarum . II . Effect of X-rays on septum formation; Baumstark-Khan C et al.; Thin sections of budding yeast cells and giant gells grown after X-irradiation have been examined by electron microscopy . The different steps of cross-wall formation during budding were documented with unirradiated cells . With X-ray induced giant cells cytokinesis was shown to be absent . Neither primary nor secondary septae appeared thus cell separation did not occur . Despite this fact both macromolecular synthesis and bud growth continued, giving rise to the formation of giant cells. Nauchnye Doki Vyss Shkoly Biol Nauki, 1985, (2), 93 - 9 {Iron accumulation by saccharomycete yeasts growing on media with an elevated iron content}; Kovalev LM et al.; In the absence of the artificial complexons of iron the intracellular iron content in yeast Saccharomyces cerevisiae are determined by the concentration of ions Fe(II) in medium . As iron is accumulated by yeast mainly in threevalency state the principal internal factor determining the intracellular iron content with existing concentration of Fe(II) in medium can be supposed to be redaction-oxidation state of yeast cell. Gene, 1985, 36(3), 333 - 40 Analysis of the inducible MEL1 gene of Saccharomyces carlsbergensis and its secreted product, alpha-galactosidase (melibiase); Sumner-Smith M et al.; We have determined both the nucleotide sequence of the MEL1 gene of Saccharomyces carlsbergensis and the N-terminal amino acid (aa) sequence of its extracellular gene product, alpha-galactosidase (melibiase) (alpha-Gal) . The predicted translation product of MEL1 is a pre-alpha-Gal protein containing an 18 aa N-terminal signal sequence for secretion . The purified enzyme is a dimer consisting of two 50-kDal polypeptides, each of which is glycosylated with no more than eight side chains . The 5'-flank of the MEL1 gene contains a region (UASm) having certain areas of sequence homology to similar sites found upstream of the structural genes GAL1, GAL7 and GAL10, which are also regulated by the action of the products of genes GAL4 and GAL80 . There are three TATA boxes between UASm and the initiation codon of pre-alpha-Gal, as well as a typical yeast cleavage/polyadenylation sequence in the 3'-flank of the gene. Gene, 1985, 34(2-3), 363 - 6 Vectors with restriction-site banks . III . Escherichia coli-Saccharomyces cerevisiae shuttle vectors; Heusterspreute M et al.; The bank of unique restriction sites present in plasmid pJRD158 has been incorporated into new vectors carrying selective markers and replicons derived from commonly used Escherichia coli-Saccharomyces cerevisiae shuttle vectors pJDB207 and YRp7 . The new vectors pMH158 and pJO158 have 21 and 23 unique restriction sites, respectively, and their complete DNA sequences are known. Biochim Biophys Acta, 1985, 806(2), 290 - 304 Mitochondrial adenosine triphosphatase in mit- mutants of Saccharomyces cerevisiase with defective subunit 6 of the enzyme complex; Choo WM et al.; mit- Mutants carrying genetically defined mutations in the oli2 region of the mitochondrial DNA were analysed . Most of these mutants demonstrated either the absence of subunit 6 or its replacement by shorter mitochondrial translation products which could be shown to be structurally related to subunit 6 by using a rabbit anti F1F0-antiserum, and by limited proteolytic mapping of the new mitochondrial translation products . Three representative oli2 mit- strains were analysed for the effects of a grossly altered subunit 6 or of a complete absence of this subunit on the activity and assembly of the H+-ATPase . Our results suggest that this subunit is not required for the assembly of the proton channel of the enzyme complex . Thus, in the absence of subunit 6, the mitochondrial respiratory activities in the oli2 mutants were found to be still sensitive to oligomycin, a specific inhibitor of the H+-ATPase proton channel . Immunoprecipitation of the assembled H+-ATPase subunits from these mutant strains using a monoclonal anti-beta-subunit antibody indicates that subunit 6 is also not essential for the assembly of most F1 subunits to components of the F0 sector. Tsitol Genet, 1984 Nov-Dec, 18(6), 455 - 7 {Mutagenic action of 5 prospective pesticides on mouse bone marrow, in a culture of human peripheral blood lymphocytes and on saccharomycete yeasts}; L'vova TS; Five pesticides are studied for their mutagenicity in bone marrow cells of mice, culture of human peripheral lymphocytes and yeasts Saccharomyces cerevisiae . It is established that dimatyph (diaethylene imidamido-thio-phosphorous acid) induced potent mutagenic effect in all three test-systems; endosulfan was genetically active in mice and yeasts . Cypermethrin increased the level of chromosome aberrations in mice bone marrow cells only in a high dose . Picloram was genetically active only in yeasts . Crotoxyphos did not reveal mutagenicity in all the tests used . The carried studies confirm that various tests should be used for detecting mutagenic activity of pesticides. FEBS Lett, 1984 Sep 3, 174(2), 233 - 7 Some properties of membrane-bound, solubilized and reconstituted into liposomes H+-ATPase of vacuoles of Saccharomyces carlsbergensis; Lichko LP et al.; Vacuoles of yeast grown in peptone medium possessed high ATPase activity (up to 1 mumol X mg protein-1 X min-1) . Membrane-bound and solubilized ATPase activities were insensitive to vanadate and azide, but were inhibited by NO-3 . K+ and cyclic AMP stimulated both membrane-bound and solubilized ATPase activities . Dio-9 activated the membrane form of vacuolar ATPase 1.5-2-fold and did not affect the solubilized enzyme . Solubilized and partially purified vacuolar ATPase was reconstituted with soy-bean phospholipids by a freeze-thaw procedure . ATPase activities in native vacuoles and proteoliposomes were stimulated effectively by Dio-9, the protonophore FCCP and ionophores valinomycin and nigericin . ATP-dependent H+ transport into proteoliposomes was also shown by quenching of ACMA fluorescence . Vacuolar and partially purified ATPase preparations possessed also GTPase activity . Unlike ATPase, however, GTPase was not incorporated as a proton pump into liposomes. Genetics, 1984 Jul, 107(3), 355 - 65 Coincident gene conversion during mitosis in saccharomyces; Golin JE et al.; During mitosis, gene conversion events at the TRP5 locus on chromosome VII are coupled with conversion events at LEU1, a locus 18 cM away, 1200 times more frequently than would be expected for two independent acts of recombination . Such coincident conversion events that occur over relatively long distances could be due to several mechanisms . We discuss these possibilities and describe an experiment that indicates that a portion of coincident events is due to extensive heteroduplexes . The phenomenon of coincident gene conversion is discussed in relation to our earlier evidence that spontaneous recombination between homologues occurs prereplicationally in mitosis. J Bacteriol, 1984 Apr, 158(1), 269 - 78 Sequence of the Saccharomyces GAL region and its transcription in vivo; Citron BA et al.; In Saccharomyces, the enzymes used to convert galactose to glucose are specified by three coordinately expressed, tightly linked genes, GAL7, GAL10, and GAL1 . These genes are induced by galactose and are controlled by the positive regulator gene gal4 and the negative regulator gene gal80 . GAL81 mutations, which are known to alter the gal4 protein, produce a constitutive phenotype . We have cloned fragments of Saccharomyces carlsbergensis DNA that span 26.3 kilobases surrounding the three clustered GAL genes . About 5 kilobases of the sequence was determined, which includes the entire GAL1 gene, the two intercistronic regions, and portions of the coding sequences of GAL10 and GAL7 . Some amino acid homology between the GAL1 gene product, galactokinase, and the Escherichia coli galactokinase was detected . By using various Saccharomyces DNA fragments, the accumulation of GAL1 and GAL10 RNA in yeast cells after induction with galactose was studied . Our results, using wild-type, gal4-, gal80-, and GAL81-1- yeast cells, support the hypothesis that control is exerted at the transcriptional level. Ecotoxicol Environ Saf, 1984 Apr, 8(2), 162 - 6 The effect of trichloroethylene and acrylonitrile on RNA and ribosome synthesis and ribosome content in Saccharomyces cells; Lochmann ER et al.; The effects of trichloroethylene (TCE) and acrylonitrile (ACN) on growth, RNA synthesis, ribosome synthesis, and ribosome content were tested in yeast cells . TCE causes a delay of the growth of a cell culture (prolongation of the lag phase), but does not cause inhibition . Cells exposed to increasing concentrations of ACN show increasing damage, so that, at a certain point of the growth curve, cell division stops altogether . Similar results were obtained when RNA synthesis was investigated: After treatment with TCE, the maximum RNA synthesis of the cell culture was retarded, but subsequently reached the same level as the untreated control cells . In the presence of ACN, however, the rate of RNA synthesis was lowered with increasing ACN concentrations . The same effect was observed upon investigation of ribosome synthesis: Whereas TCE produces only a slight effect, treatment with increasing concentrations of ACN leads to a substantial decrease in ribosome synthesis, and finally to total inhibition . Parallel to this, the content of free and membrane-bound ribosomes is diminished . Obviously, the decrease in ribosome content is caused not only by an inhibition of ribosome synthesis, but also by a degradation of existing ribosomes, as well as by induction of a ribosome-associated RNase. Biokhimiia, 1984 Apr, 49(4), 540 - 6 {Kinetic and allosteric properties of highly-purified, biosynthetic L-threonine dehydrogenase from brewer's yeast Saccharomyces carlsbergensis}; Kovaleva SV et al.; Kinetic and allosteric propeties of highly purified "biosynthetic" L-threonine dehydratase from brewer's yeast S . carlbergensis were studied at three pH values, using L-threonine and L-serine as substrates . It was shown that the plot of the initial reaction rate (v) versus initial substrate concentrations ({S}0 pH 6.5 is hyperbolic (Km=5.0.10-2M), while these at pH 7.8 and 9.5 have a faintly pronounced sigmoidal shape with fast occurring saturation plateaus ({S}0.5= 1.0.10-2 and 0.9.10-2M, respectively) . the ratios between L-threonine and L-serine dehydratation rates depend on pH . The kinetic properties and the dependence of substrate specificity on pH suggest that the enzyme molecule undergoes pH-induced (at pH 7.0) conformational changes . The determination of pK values of the enzyme functional groups involved in L-threonine binding demonstrated that these groups have pK is approximately equal to 7.5 and 9.5 . The latter group was hypothetically identified as a epsilon-NH2-group of the lysine residue . High concentrations of the allosteric inhibitor (L-isoleucine) decrease the rates of L-threonine and L-serine dehydratation and induce the appearance (at pH 6.5) or increase (at pH 7.9 and 9.5) of homotropic cooperative interactions between the active sites in the course of L-threonine dehydratation . The enzyme inhibition by L-isoleucine increases with a decrease of L-threonine concentrations . Low L-isoleucine concentrations, as well as the enzyme activator (L-valine) stimulate the enzyme at non-saturating substrate concentrations (when L-threonine or L-serine are used as substrates) without normalization of (v) versus {S}0 plots . The maximal activation of the enzyme is observed at pHG 8.5--9.0 . It is assumed that the molecule of "biosynthetic" L-threonine dehydratase from brewer's yeast contains two types of sites responsible for the effector binding, i.e., "activatory" and "inhibitory" ones. Appl Environ Microbiol, 1984 Apr, 47(4), 681 - 4 Influence of the membrane on T-2 toxin toxicity in Saccharomyces spp; Schappert KT et al.; In growing cells of Saccharomyces cerevisiae and Saccharomyces carlsbergensis, T-2 toxin inhibits cell growth . We have examined the role of the yeast membranes in the uptake mechanism(s) of T-2 toxin . The effects of membrane-modulating agents, ethanol, cetyltrimethylammonium bromide, Triton X-100, and heat were studied; these agents were found to increase the sensitivity of the yeasts toward T-2 toxin . In the presence of 5% (vol/vol) ethanol, 2 micrograms of T-2 toxin per ml caused complete inhibition of growth . In the presence of 1 microgram of cetyltrimethylammonium bromide per ml, yeast cells became sensitive to T-2 toxin, starting with a concentration of 0.5 micrograms/ml . Triton X-100 at concentrations below 1% (vol/vol) sensitized the cells toward T-2 toxin, but at higher concentrations it protected the cells from T-2 toxin . Temperatures of incubation between 7 and 30 degrees C influenced the growth reduction caused by T-2 toxin . The greatest observed reduction of growth in T-2 toxin-treated cultures occurred at 30 degrees C . To further prove that the membrane influences the interaction of T-2 toxin with yeasts, we have studied a yeast mutant with a reduced plasma membrane permeability (G . H . Rank et al., Mol . Gen . Genet . 152:13-18, 1977) . This yeast mutant proved to be resistant to T-2 toxin concentrations of up to 50 micrograms/ml . These results show that the membrane plays a significant role in the interaction of T-2 toxin with yeast cells. Biochim Biophys Acta, 1984 Mar 7, 792(3), 310 - 7 Uptake of fatty acids by the yeasts, Saccharomyces uvarum and Saccharomycopsis lipolytica; Kohlwein SD et al.; Yeast cells take up exogenous fatty acids with subsequent rapid incorporation into glycerolipids . beta-Oxidation does not occur in Saccharomyces uvarum and is observed in Saccharomycopsis lipolytica only 2-5 min after addition of radioactively labeled fatty acid . Rates of fatty acid uptake are linear up to 30 s with S . lipolytica and up to 2 min with S . uvarum . The uptake kinetics are consistent with a dual mode of transport, comprising a saturable component with KT values in the range 10(-5)-10(-6) M, and apparently simple diffusion that predominates at high substrate concentrations . Kinetics of fatty acid permeation are independent of metabolic energy and membrane potential . At least two fatty acid carrier systems exist in both S . lipolytica and S . uvarum, one being specific for fatty acids with 12 and 14 C atoms, respectively, the other for C16 and C18 saturated or unsaturated fatty acids . Octanoic acid and decanoic acid are not taken up by S . lipolytica . Internalization of lauric acid and oleic acid by S . lipolytica cells is preceded by a rapid (less than 5 s) initial uptake which most likely represents irreversible adsorption . This phenomenon was not observed with heat-inactivated S . lipolytica cells or with viable S . uvarum . In azide-poisoned cells of S . lipolytica an up to 20-fold accumulation of unesterified fatty acid was observed within 30 s after the addition of substrate. Radiobiologiia, 1984 Mar-Apr, 24(2), 173 - 9 {Radiosensitive mutants of yeast-Saccharomyces with disruptions in the cell division cycle . Cell inactivation by restrictive temperature, ultra-violet and ionizing radiation in relation to the passage of the generated cycle}; Landa SB et al.; Three thermo- and radiosensitive mutants of yeast-Saccharomyces were used to study cell inactivation under the effect of elevated temperature, UV-light, and ionizing radiation . The forms of cell inactivation were shown to be identical with all the factors under study and to resemble lethal "terminal phenotypes" of Hartwell cds mutants . It is suggested that the cell division cycle is blocked due to the disorders in the system of gene product synthesis and not to defects in the enzymes themselves. J Cell Biol, 1984 Mar, 98(3), 922 - 33 Structural rearrangements of tubulin and actin during the cell cycle of the yeast Saccharomyces; Kilmartin JV et al.; The distribution of actin and tubulin during the cell cycle of the budding yeast Saccharomyces was mapped by immunofluorescence using fixed cells from which the walls had been removed by digestion . The intranuclear mitotic spindle was shown clearly by staining with a monoclonal antitubulin; the presence of extensive bundles of cytoplasmic microtubules is reported . In cells containing short spindles still entirely within the mother cells, one of the bundles of cytoplasmic microtubules nearly always extended to (or into) the bud . Two independent reagents (anti-yeast actin and fluorescent phalloidin) revealed an unusual distribution of actin: it was present as a set of cortical dots or patches and also as distinct fibers that were presumably bundles of actin filaments . Double labeling showed that at no stage in the cell cycle do the distributions of actin and tubulin coincide for any significant length, and, in particular, that the mitotic spindle did not stain detectably for actin . However, both microtubule and actin staining patterns change in a characteristic way during the cell cycle . In particular, the actin dots clustered in rings about the bases of very small buds and at the sites on unbudded cells at which bud emergence was apparently imminent . Later in the budding cycle, the actin dots were present largely in the buds and, in many strains, primarily at the tips of these buds . At about the time of cytokinesis the actin dots clustered in the neck region between the separating cells . These aspects of actin distribution suggest that it may have a role in the localized deposition of new cell wall material. Biochim Biophys Acta, 1984 Feb 14, 797(2), 231 - 8 Purification and characterization of alpha-glucosidases produced by Saccharomyces in response to three distinct maltose genes; Tabata S et al.; alpha-Glucosidases or maltases (EC 3.2.1.20) were purified to electrophoretic homogeneity from a respective strain of Saccharomyces cerevisiae which carries a single MAL gene, either MAL alpha, MAL beta, or MAL gamma, using gluconate-Sepharose affinity chromatography and isoelectrofocusing . Of these maltases, two types of maltase were obtained from the MAL gamma strain, the pI values of which were 5.6 and 5.9 . From the MAL alpha and MAL beta strain was obtained only one type of maltase with the pI at 5.6 which was identical to one of the maltases from the MAL gamma strain . These four maltases possessed the same properties, except for pI . They were monomers with molecular weights of between 66 000 and 67 000 . With regard to the substrate specificity, they hydrolyzed maltose and sucrose exclusively but not alpha-methylglucoside nor maltooligosaccharide . They did not differ in immunological properties. Radiat Environ Biophys, 1984, 23(1), 19 - 30 Radiation induced formation of giant cells (Saccharomyces uvarum) . I . Budding process and chitin ring formation; Baumstark-Khan C et al.; X-irradiated yeast cells (Saccharomyces uvarum) grown in liquid media stop mitosis and form giant cells . Chitin ring formation, being a prerequisite for cell separation, was studied by fluorescence microscopy using calcofluor white, a chitin specific dye . Experiments with inhibitors of DNA synthesis (hydroxyurea) and chitin synthesis (polyoxin D) demonstrate chitin ring formation to be dependent on DNA synthesis, whereas bud formation is independent of DNA synthesis and chitin ring formation respectively . Basing on these results the formation of X-ray induced giant cells implies one DNA replication which in turn induces the formation of only one chitin ring between mother cell and giant bud . Obviously no septum can be formed . Thus cell separation does not occur, but the bud already formed, produces another bud demonstrating that bud formation itself is independent of DNA synthesis. Arzneimittelforschung, 1984, 34(7), 794 - 7 Bacterio-pharmacological activity of Saccharomyces boulardii in clindamycin-induced colitis in the hamster; Massot J et al.; The effect of S . boulardii on experimental colitis induced by the single oral administration of 1 mg/kg of clindamycin in the Syrian hamster was studied . Oral administration of S . boulardii for 13 days, starting 3 days prior to the administration of clindamycin, significantly reduced the mortality rate and inhibited the growth of C . difficile in the caecum and colon . There was a marked improvement in the sub-mucosa and mucosa which showed major inflammatory lesions when clindamycin was administered alone. Annu Rev Genet, 1984, 18, 233 - 70 The synthesis and function of proteases in Saccharomyces: genetic approaches; Jones EW; Genetic analysis has clarified the role of the major defined proteases in the life of yeast cells . The proteases of the vacuole are clearly involved in the massive proteolysis that occurs when cells are starved for nitrogen and in the (re)utilization of peptides . They appear not to be involved in any of the specific proteolyses that have been described . kex1, kex2, ste13, bar1 (sst1), and pep4 mutants have the characteristics expected of mutants defective in specific proteolytic events . Hence, the genetic attack on these specific proteolyses and the identification and characterization of the responsible proteases seem well under way and we can expect answers in the near future . The biggest lacuna in our understanding of proteolysis in yeast is the identity of the protease(s) or proteolytic system(s) involved in metabolically triggered proteolytic degradations and in housekeeping functions such as degradation of nonfunctional subunits and aberrant proteins . Genetic entries into these problems appear to be rare or difficult . Here lies the greatest challenge. Nauchnye Doki Vyss Shkoly Biol Nauki, 1984, (12), 96 - 100 {Determination of iron in saccharomycete yeasts by the dipyridyl method}; Kovalev LM et al.; Iron content in intact yeast cells without their incineration or disintegration can be determined using 2,2'-dipyridyl. Mikrobiologiia, 1984 Jan-Feb, 53(1), 58 - 62 {Limiting the growth of Saccharomyces serevisiae yeasts under chemostat conditions by carbon and nitrogen sources}; Shkidchenko AN; Chemostat Saccharomyces cerevisiae cultures were obtained at D = 0.066 h-1 and growth limitation with ethanol and a nitrogen source with similar population densities . The threshold concentration of ethanol was 0.1 g/L and that of nitrogen 0.014 g/L . The optimal specific load of ethanol was 2.5--3.5 g/g biomass per hour with the economic coefficient of 40% . At the constant specific ethanol load, the economic coefficient changed at different rates of flow . The cultures differed in the content and amino acid composition of protein. Arch Microbiol, 1984 Jan, 137(1), 10 - 3 L-Arabinose is not a gratuitous inducer of alpha-galactosidase from Saccharomyces carlsbergensis; Carmenes RS et al.; L-Arabinose has been described as a gratuitous inducer of the yeast alpha-galactosidase . This has been found to be an artefact resulting from galactose c