Genomic reorganization between two sibling yeast species,Saccharomyces bayanus and Saccharomyces cerevisiae

Genomic comparison of two sibling yeast species, Saccharomyces bayanus and Saccharomyces cerevisiae, was performed by Southern blot analysis with various S. cerevisiae gene probes following electrophoretic karyotyping. Fifteen genes on chromosome IV of S. cerevisiae were examined and classified into two groups. Gene probes of CEN4 and TRP1, as well as six other genes located on the left arm of the chromosome hybridized to a 1100-kb chromosome of S. bayanus that is smaller than chromosome IV of S. cerevisiae. On the other hand, probes of seven genes located on the right arm of chromosome IV hybridized to a 1350-kb chromosome that is homeologous to chromosome IV, judging from its size. Two genes located on the left arm of chromosome II hybridized to the 1350-kb chromosome, while four genes on the right arm hybridized to the 1100-kb chromosome. These pieces of evidence indicate that chromosomes II and IV of S. cerevisiae are rearranged into 1350-kb and 1100-kb chromosomes in S. bayanus. Furthermore, it is suggested that chromosome XV is rearranged into two chromosomes (800 and 850 kb in size) in S. bayanus. The translocation points of chromosomes II and IV were delimited using S. cerevisiae prime clone membranes. The results indicated that the translocation points are located close to the FUR4 locus on chromosome II and close to the RAD57 locus on chromosome IV.     

Designer deletion and prototrophic strains derived from Saccharomyces cerevisiae strain W303‐1a

We report the construction of Saccharomyces cerevisiae strains isogenic to W303‐1a that are designed to allow efficient genetic analysis. To facilitate the generation of null alleles of target genes by PCR‐mediated gene disruption, we constructed designer deletion alleles of the ARG4, TRP1 and URA3 genes. In addition, a single pair of oligonucleotide primers were designed that can be used to amplify any of several marker genes for use in PCR‐mediated gene disruption. A new version of the ‘reusable’ hisG‐URA3‐hisG cassette was constructed for use in PCR‐mediated gene disruption. Finally, to facilitate the formation of isogenic diploids by selection, we constructed strains that contain combinations of wild‐type alleles of ADE2, HIS3, LEU2, TRP1 and URA3. Copyright © 1999 John Wiley & Sons, Ltd.     

The Saccharomyces cerevisiae enolase‐related regions encode proteins that are active enolases

In addition to two genes (ENO1 and ENO2) known to code for enolase (EC4.2.1.11), the Saccharomyces cerevisiae genome contains three enolase‐related regions (ERR1, ERR2 and ERR3) which could potentially encode proteins with enolase function. Here, we show that products of these genes (Err2p and Err3p) have secondary and quaternary structures similar to those of yeast enolase (Eno1p). In addition, Err2p and Err3p can convert 2‐phosphoglycerate to phosphoenolpyruvate, with kinetic parameters similar to those of Eno1p, suggesting that these proteins could function as enolases in vivo. To address this possibility, we overexpressed the ERR2 and ERR3 genes individually in a double‐null yeast strain lacking ENO1 and ENO2, and showed that either ERR2 or ERR3 could complement the growth defect in this strain when cells are grown in medium with glucose as the carbon source. Taken together, these data suggest that the ERR genes in Saccharomyces cerevisiae encode a protein that could function in glycolysis as enolase. The presence of these enolase‐related regions in Saccharomyces cerevisiae and their absence in other related yeasts suggests that these genes may play some unique role in Saccharomyces cerevisiae. Further experiments will be required to determine whether these functions are related to glycolysis or other cellular processes. Copyright © 2012 John Wiley & Sons, Ltd.     

Sequence of the open reading frame of the FL01 gene from Saccharomyces cerevisiae

The cloned part of the flocculation gene FLO1 of Saccharomyces cerevisiae (Teunissen, A.W.R.H., van den Berg, J.A. and Steensma, H.Y. (1993). Physical localization of the flocculation gene FLO1 on chromosome I of Saccharomyces cerevisiae, Yeast, in press) has been sequenced. The sequence contains a large open reading frame of 2685 bp. The amino acid sequence of the putative protein reveals a serine- and threonine-rich C-terminus (46%), the presence of repeated sequences and a possible secretion signal at the N-terminus. Although the sequence is not complete (we assume the missing fragment consists of repeat units), these data strongly suggest that the protein is located in the cell wall, and thus may be directly involved in the flocculation process.     

Sequence and analysis of 24 kb on chromosome II of Saccharomyces cerevisiae

In the course of the European yeast genome sequencing project, we determined 23,920 bp of a continuous chromosome II right arm sequence. Analysis of data revealed 13 open reading frames (ORFs), three of which corresponded to previously identified genes; two tRNA genes and one repetitive element. One ORF showed considerable homology (46%) to a hypothetical chromosome III gene; another, putatively very hydrophobic gene product, was 30% identical to the heat-shock protein HSP30. Two ORFs were homologous to human genes. The complete sequence was submitted to the EMBL data bank under the Accession Number Z46260 Authorin submission ‘3’.     

Sequence Analysis of 203 Kilobases from Saccharomyces cerevisiae Chromosome VII

The nucleotide sequences of five major regions from chromosome VII of Saccharomyces cerevisiae have been determined and analysed. These regions represent 203 kilobases corresponding to approximately one-fifth of the complete yeast chromosome VII. Two fragments originate from the left arm of this chromosome. The first one of about 15·8 kb starts approximately 75 kb from the left telomere and is bordered by the SKI8 chromosomal marker. The second fragment covers the 72·6 kb region between the chromosomal markers CYH2 and ALG2. On the right chromosomal arm three regions, a 70·6 kb region between the MSB2 and the KSS1 chromosomal markers and two smaller regions dominated by the KRE11 marker and another one in the vicinity of the SER2 marker were sequenced. We found a total of 114 open reading frames (ORFs), 13 of which were completely overlapping with larger ORFs running in the opposite direction. A total of 44 yeast genes, the physiological functions of which are known, could be precisely mapped on this chromosome. Of the remaining 57 ORFs, 26 shared sequence homologies with known genes, among which were 13 other S. cerevisiae genes and five genes from other organisms. No homology with any sequence in the databases could be found for 31 ORFs. Furthermore, five Ty elements were found, one of which may not be functional due to a frame shift in its Ty1B amino acid sequence. The five chromosomal regions harboured five potential ARS elements and one sigma element together with eight tRNA genes and two snRNAs, one of which is encoded by an intron of a protein-coding gene. © 1997 by John Wiley & Sons, Ltd.     

Sequence of a 4·8 kb fragment of Saccharomyces cerevisiae chromosome II including three essential open reading frames

The nucleotide sequence of a fragment of 4867 base pairs of Saccharomyces cerevisiae chromosome II has been determined. The sequence contains three complete open reading frames. In addition to the already known gene RPB5, coding for a subunit shared by all three DNA directed RNA polymerases, two new open reading frames could be identified. YBR12.03 codes for a protein of 183 amino acids with homology to one of the proteins of the Bacillus subtilis riboflavin biosynthesis operon (RibG). Deletion mutants of YBR12.03 can germinate but stop growing after five to seven cell divisions on YPD. Supplementation with high concentrations of riboflavin does promote growth. YBR12.05 codes for a protein of 386 amino acids with homology to STI1, a stress-inducible protein of S. cerevisiae. Deletion mutants of YBR12.05 are not viable.     

The chromosomal constitution of wine strains of Saccharomyces cerevisiae

A general procedure is described for determining the chromosomal constitution of industrial strains of Saccharomyces cerevisiae based on analysis of segregation frequencies for input markers among random spore progeny of industrial-laboratory strain hybrids. The multiply auxotrophic haploid testers used carried a dominant erythromycin-resistance marker, allowing hybrids to be selected in mass matings with spores produced by the wild-type industrial strains. Analysis of a number of independent crosses between the haploid testers and an unselected population of spores of each wine strain distinguished between disomic, trisomic and tetrasomic chromosomal complements in the parents. Possible explanations for a significant class of aberrant segregation frequencies are discussed. Results of the analysis indicate that UCD Enology 522 (Montrachet) is diploid and possibly trisomic for chromosome VII; 522X is diploid; UCD Enology 505 (California Champagne) is disomic for chromosome XVI, trisomic for chromosomes I, II, III, VI, VIII, IX, X, XII, XV, tetrasomic for chromosomes IV, XI, XIII, XIV and either trisomic or tetrasomic for chromosomes V and VII; and that UCD Enology 595 (Pasteur Champagne) is disomic for chromosomes I, II, III, IX, XVI, trisomic for chromosomes IV, VI, X, XII, XIV, XV, tetrasomic for chromosomes V, VIII, XI, XIII and either disomic or tetrasomic for chromosome VII.     

固态发酵用耐高温酿酒酵母YH_4的筛选及其特性研究

Saccharomyces cere(?)isiae YH(?)是从洋河酒厂处于顶火期的酒醅中分离出来的耐高温酵母,最适生长温度为35～38℃,最高生长温度为47℃。最适生长PH为4～6,对黄水中复合有机酸有较强的耐性。酒精发酵能力中等,发酵速度较慢。在实验室模拟固态发酵条件下,当对酒醅的接种量在2％以下时,将会使酒精产量明显增加,而且酒中的己酸乙酯含量不受显著影响,因此,该菌株在克服或减轻浓香型白酒夏季生产“掉排”现象中较有应用前途。 本文介绍了YH(?)的微生物学特征及应用特性,同时,探索和改进了一些实验室进行固态模拟发酵的方法。     

野生酵母和商品酵母发酵葡萄酒中挥发性成分差异研究

采用顶空固相微萃取（HS-SPME）和气相色谱-质谱联用（GC-MS）技术对5株商品酿酒酵母和7株野生酿酒酵母所酿葡萄酒中的挥发性物质进行分析。结果表明,各葡萄酒中挥发性物质的组成成分相差不大,但在含量上存在差异,野生酿酒酵母所酿造的葡萄酒中主要挥发性物质的总含量要高于商品酿酒酵母。对于葡萄酒中主要由酵母代谢产生的3类挥发性物质—酯类、醇类和酸类,其含量最高的均为用野生酿酒酵母酿造的葡萄酒,其中以W2和W7最为突出。感官分析结果表明,C1、C2和W2的果香、花香较为突出,C4和W2具有明显的草本味,C2和W1的胡椒味较强。      

Sequence and analysis of a 26·9 kb fragment from chromosome XV of the yeast Saccharomyces cerevisiae

We have determined the nucleotide sequence of a fragment of chromosome XV of Saccharomyces cerevisiae cloned into cosmid pEOA048. The analysis of the 26 857 bp sequence reveals the presence of 19 open reading frames (ORFs), and of one RNA-coding gene (SNR17A). Six ORFs correspond to previously known genes (MKK1/SSP32, YGE1/GRPE/MGE1, KIN4/KIN31/KIN3, RPL37B, DFR1 and HES1, respectively), all others were discovered in this work. Only five of the new ORFs have significant homologs in public databases, the remaining eight correspond to orphans (two of them are questionable). O5248 is a probable folylpolyglutamate synthetase, having two structural homologs already sequenced in the yeast genome. O5273 shows homology with a yeast protein required for vanadate resistance. O5268 shows homology with putative oxidoreductases of different organisms. O5257 shows homology with the SAS2 protein and another hypothetical protein from yeast. The last one, O5245, shows homology with a putative protein of Caenorhabditis elegans of unknown function. The present sequence corresponds to coordinates 772 331 to 799 187 of the entire chromosome XV sequence which can be retrieved by anonymous ftp (ftp. mips. embnet. org).     

Sequence of the HMR region on chromosome III of Saccharomyces cerevisiae.

A 10,095 base pair DNA fragment from the right arm of chromosome III of Saccharomyces cerevisiae has been sequenced and analysed. It encompasses the silent mating-type locus HMR. Both HMRa1 and HMRa2 genes, as well as their flanking regulatory regions, have been identified. Three new open reading frames longer than 80 amino acid residues were found in this fragment. One of them (YCR137) shows features compatible with a membranous localization and a transporter function. The other two do not show a similarity with any known gene. A new gene coding for tRNA(thr)al (ACU) has been identified. It is located in a region coding for several delta sequences.     

2株酵母菌单倍体原生质体形成与再生条件的研究

对酒精高产酿酒酵母GGFS16和GJ2008单倍体原生质体的形成与再生条件进行了研究.结果表明,在菌龄8h、o.2％p-巯基乙醇和0.1％ EDTA-Na2预处理20min、1.5％的蜗牛酶37℃处理30min以及使用浓度170g/L的蔗糖作为渗透压稳定剂的条件下,GGFS16和GJ2008单倍体原生质体的形成率和再生率均达到最大.形成率分别是98.14％和97.19％,再生率分别是17.29％和15.78％.     

Purification of isocitrate lyase from Saccharomyces cerevisiae

Isocitrate lyase purified to homogeneity from Saccharomyces cerevisiae was composed of four identical subunits with a molecular mass of 75 kDa. The enzyme was most active at pH 7.0 in the presence of 5 mM-Mg2+. The Km value for threo-Ds-isocitrate was 1.4 mM. Isocitrate lyase was shown to be thermostable at 50 degrees C for 60 min at a high salt concentration, but rapidly lost activity at -20 degrees C or by dialysis.