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1

Saccharomyces cerevisiae  

PubMed Central

Yeast prions are infectious proteins that spread exclusively by mating. The frequency of prions in the wild therefore largely reflects the rate of spread by mating counterbalanced by prion growth slowing effects in the host. We recently showed that the frequency of outcross mating is about 1% of mitotic doublings with 23–46% of total matings being outcrosses. These findings imply that even the mildest forms of the [PSI+], [URE3] and [PIN+] prions impart > 1% growth/survival detriment on their hosts. Our estimate of outcrossing suggests that Saccharomyces cerevisiae is far more sexual than previously thought and would therefore be more responsive to the adaptive effects of natural selection compared with a strictly asexual yeast. Further, given its large effective population size, a growth/survival detriment of > 1% for yeast prions should strongly select against prion-infected strains in wild populations of Saccharomyces cerevisiae. PMID:23764836

Kelly, Amy C.; Wickner, Reed B.

2013-01-01

2

Characteristics of Saccharomyces cerevisiae yeasts exhibiting rough colonies and pseudohyphal morphology with respect to alcoholic fermentation  

PubMed Central

Among the native yeasts found in alcoholic fermentation, rough colonies associated with pseudohyphal morphology belonging to the species Saccharomyces cerevisiae are very common and undesirable during the process. The aim of this work was to perform morphological and physiological characterisations of S. cerevisiae strains that exhibited rough and smooth colonies in an attempt to identify alternatives that could contribute to the management of rough colony yeasts in alcoholic fermentation. Characterisation tests for invasiveness in Agar medium, killer activity, flocculation and fermentative capacity were performed on 22 strains (11 rough and 11 smooth colonies). The effects of acid treatment at different pH values on the growth of two strains (“52” - rough and “PE-02” - smooth) as well as batch fermentation tests with cell recycling and acid treatment of the cells were also evaluated. Invasiveness in YPD Agar medium occurred at low frequency; ten of eleven rough yeasts exhibited flocculation; none of the strains showed killer activity; and the rough strains presented lower and slower fermentative capacities compared to the smooth strains in a 48-h cycle in a batch system with sugar cane juice. The growth of the rough strain was severely affected by the acid treatment at pH values of 1.0 and 1.5; however, the growth of the smooth strain was not affected. The fermentative efficiency in mixed fermentation (smooth and rough strains in the same cell mass proportion) did not differ from the efficiency obtained with the smooth strain alone, most likely because the acid treatment was conducted at pH 1.5 in a batch cell-recycle test. A fermentative efficiency as low as 60% was observed with the rough colony alone. PMID:24688501

Reis, Vanda Renata; Bassi, Ana Paula Guarnieri; da Silva, Jessica Carolina Gomes; Ceccato-Antonini, Sandra Regina

2013-01-01

3

SACCHAROMYCES CEREVISIAE 03.01.03  

E-print Network

- SACCHAROMYCES CEREVISIAE 03.01.03 � 2014 #12- . , . , , , , , . . , , , #12;6 . , , , . , , , . . Saccharomyces cerevisiae W303. .. ( , , 27, ) http://www.bio.msu.ru. � � __________ 2014 . .. #12;3 . Saccharomyces

Kaplan, Alexander

4

Genomic Convergence toward Diploidy in Saccharomyces cerevisiae  

E-print Network

Genomic Convergence toward Diploidy in Saccharomyces cerevisiae Aleeza C. Gerstein, Hye-Jung E initially isogenic lines of the yeast Saccharomyces cerevisiae. Over the course of ;1,800 generations the budding yeast Saccharomyces cerevisiae as a model system, experimental evolution studies have confirmed

Otto, Sarah

5

Original article The effect of Saccharomyces cerevisiae  

E-print Network

Original article The effect of Saccharomyces cerevisiae and Aspergillus oryzae on fermentations of Saccharomyces cerevisiae (SC 50 mg/day) and Aspergillus oryzae (AO 3 g/day) on the fermentation processes and reprints #12;Résumé ― Effet de Saccharomyces cerevisiae et Aspergillus oryzae sur les fermentations

Boyer, Edmond

6

Local Regulatory Variation in Saccharomyces cerevisiae  

E-print Network

Local Regulatory Variation in Saccharomyces cerevisiae James Ronald1,2 , Rachel B. Brem2 regulatory variation in Saccharomyces cerevisiae. We used genetic linkage analysis to show that nearly in Saccharomyces cerevisiae. PLoS Genet 1(2): e25. Introduction Much effort has recently been devoted

Kruglyak, Leonid

7

Xylose fermentation by Saccharomyces cerevisiae  

Microsoft Academic Search

We have performed a comparative study of xylose utilization in Saccharomyces cerevisiae transformants expressing two key enzymes in xylose metabolism, xylose reductase (XR) and xylitol dehydrogenase (XDH), and in a prototypic xylose-utilizing yeast, Pichia stipitis. In the absence of respiration (see text), baker's yeast cells convert half of the xylose to xylitol and ethanol, whereas P. stipilis cells display rather

Peter Kötter; Michael Ciriacy

1993-01-01

8

The evolutionary dynamics of the Saccharomyces cerevisiae protein interaction network  

E-print Network

The evolutionary dynamics of the Saccharomyces cerevisiae protein interaction network after) event in Saccharomyces cerevisiae. The model allowed us to predict the frequency of intergene. We apply our methodology to the protein interaction network of Saccharomyces cerevisiae (23

Kishony, Roy

9

Purification, Functional Reconstitution, and Characterization of the Saccharomyces cerevisiae Isoprenylcysteine  

E-print Network

Purification, Functional Reconstitution, and Characterization of the Saccharomyces cerevisiae carboxylmethyltransferase (Icmt) enzyme from Saccharomyces cerevisiae, Ste14p, the founding member of a homologous family14p, the Icmt from Saccharomyces cerevisiae, identified through genetic and biochemical means

Hrycyna, Christine A.

10

Metabolic Engineering of Saccharomyces cerevisiae  

PubMed Central

Comprehensive knowledge regarding Saccharomyces cerevisiae has accumulated over time, and today S. cerevisiae serves as a widley used biotechnological production organism as well as a eukaryotic model system. The high transformation efficiency, in addition to the availability of the complete yeast genome sequence, has facilitated genetic manipulation of this microorganism, and new approaches are constantly being taken to metabolicially engineer this organism in order to suit specific needs. In this paper, strategies and concepts for metabolic engineering are discussed and several examples based upon selected studies involving S. cerevisiae are reviewed. The many different studies of metabolic engineering using this organism illustrate all the categories of this multidisciplinary field: extension of substrate range, improvements of producitivity and yield, elimination of byproduct formation, improvement of process performance, improvements of cellular properties, and extension of product range including heterologous protein production. PMID:10704473

Ostergaard, Simon; Olsson, Lisbeth; Nielsen, Jens

2000-01-01

11

The proteome of Saccharomyces cerevisiae mitochondria  

E-print Network

The proteome of Saccharomyces cerevisiae mitochondria Albert Sickmann*, Jo¨ rg Reinders*, Yvonne of Saccharomyces cerevisiae mitochondria. The proteins of highly pure yeast mitochondria were separated by several were identified, indicating an involvement of mitochondria in numerous cellular processes. All known

Economou, Tassos

12

Mannitol Uptake by Saccharomyces cerevisiae  

PubMed Central

The uptake of mannitol, a nonmetabolized hexitol, by Saccharomyces cerevisiae was measured. Various characteristics examined include: effects of temperature on uptake, inhibition of uptake by uranyl nitrate, competition for uptake by glucose, counterflow of mannitol by glucose, and the affinity of mannitol for a carrier system as measured by a Michaelis constant. That energy is required for uptake was shown by a decreased uptake in the presence of energy inhibitors, by an increased uptake upon addition of energy sources, and by the absence of uptake under anaerobic conditions with no fermentable energy sources available. That mannitol is bound to some cellular constituent after it enters the cell was shown by its attachment to non-dialyzable cell fragments and by the lack of an osmotic response, both of which are consistent with a minimal efflux. PMID:5547989

Maxwell, W. A.; Spoerl, Edward

1971-01-01

13

Discontinuity Induced Bifurcations in a Model of Saccharomyces cerevisiae.  

E-print Network

Discontinuity Induced Bifurcations in a Model of Saccharomyces cerevisiae. D.J.W. Simpson1 , D.S. Kompala, Cybernetic model of the growth dynamics of Saccharomyces cerevisiae in batch and continuous is Saccharomyces cerevisiae which has been utilized for the production of bread, wine and beer for thousands

Meiss, James

14

Elevated evolutionary rates in the laboratory strain of Saccharomyces cerevisiae  

E-print Network

Elevated evolutionary rates in the laboratory strain of Saccharomyces cerevisiae Zhenglong Gu) of Saccharomyces cerevisiae and found that genes in the laboratory strain tend to evolve faster than in the wild commonly used Saccharomyces cerevisiae haploid in the laboratory, S288c, for which the whole genome

Petrov, Dmitri

15

Regulation of phospholipid synthesis in Saccharomyces cerevisiae by zinc depletion  

E-print Network

Review Regulation of phospholipid synthesis in Saccharomyces cerevisiae by zinc depletion George M online 19 May 2006 Abstract The synthesis of phospholipids in the yeast Saccharomyces cerevisiae; Transcriptional regulation; Yeast; Zinc 1. Introduction The yeast Saccharomyces cerevisiae serves as a eukaryotic

Chen, Kuang-Yu

16

Coordinated induction of multi-gene pathways in Saccharomyces cerevisiae  

E-print Network

Coordinated induction of multi-gene pathways in Saccharomyces cerevisiae Jing Liang1 , Jonathan C an important eukaryotic pro- duction host, Saccharomyces cerevisiae has never had such gene architecture. Here in eukaryotes (10). Saccharomyces cerevisiae is an important industrial pro- duction host for heterologous

Zhao, Huimin

17

SHORT REPORT Open Access Saccharomyces cerevisiae chitin biosynthesis  

E-print Network

SHORT REPORT Open Access Saccharomyces cerevisiae chitin biosynthesis activation by N added to a chitin synthase assay performed on a Saccharomyces cerevisiae membrane fraction. Findings: N]. In Saccharomyces cerevisiae, the organism in which chitin biosynthesis has been most studied, three differentially

Paris-Sud XI, Université de

18

Preferentially Quantized Linker DNA Lengths in Saccharomyces cerevisiae  

E-print Network

Preferentially Quantized Linker DNA Lengths in Saccharomyces cerevisiae Ji-Ping Wang1 *, Yvonne in the yeast Saccharomyces cerevisiae genome, using two novel methods: a Fourier analysis of genomic Linker DNA Lengths in Saccharomyces cerevisiae. PLoS Comput Biol 4(9): e1000175. doi:10.1371/journal

Wang, Ji-Ping

19

Evidence for Domesticated and Wild Populations of Saccharomyces cerevisiae  

E-print Network

Evidence for Domesticated and Wild Populations of Saccharomyces cerevisiae Justin C. Fay* , Joseph, United States of America Saccharomyces cerevisiae is predominantly found in association with human for domesticated and wild populations of Saccharomyces cerevisiae. PLoS Genet 1(1): e5. Introduction Sensu strictu

Fay, Justin

20

Original article The effect of Saccharomyces cerevisiae and Aspergillus  

E-print Network

Original article The effect of Saccharomyces cerevisiae and Aspergillus oryzae on the digestion cerevisiae / Aspergillus oryzae / protozoa / digestion / fibre Résumé - Effet de Saccharomyces cerevisiae et was to determine the effect of two probiotics, Saccharo- myces cerevisiae (SC) and Aspergillus oryzae (AO), without

Boyer, Edmond

21

Sterol methylation in Saccharomyces cerevisiae.  

PubMed Central

Various nystatin-resistant mutants defective in S-adenosylmethionine: delta 24-sterol-C-methyltransferase (EC 2.1.1.41) were shown to possess alleles of the same gene, erg6. The genetic map location of erg6 was shown to be close to trp1 on chromosome 4. Despite the single locus for erg6, S-adenosylmethionine: delta 24-sterol-C-methyltransferase enzyme activity was found in three separate fractions: mitochondria, microsomes, and the "floating lipid layer." The amount of activity in each fraction could be manipulated by assay conditions. The lipids and lipid synthesis of mutants of Saccharomyces cerevisiae defective in the delta 24-sterol-C-methyltransferase were compared with a C5(6) desaturase mutant and parental wild types. No ergosterol (C28 sterol) could be detected in whole-cell sterol extracts of the erg6 mutants, the limits of detection being less than 10(-11) mol of ergosterol per 10(8) cells. The distribution of accumulated sterols by these mutants varied with growth phase and between free and esterified fractions. The steryl ester concentrations of the mutants were eight times higher than those of the wild type from exponential growth samples. However, the concentration of the ester accumulated by the mutants was not as great in stationary-phase cells. Whereas the head group phospholipid composition was the same between parental and mutant strains, strain-dependent changes in fatty acids were observed, most notably a 40% increase in the oleic acid content of phosphatidylethanolamine of one erg6 mutant, JR5. PMID:6363386

McCammon, M T; Hartmann, M A; Bottema, C D; Parks, L W

1984-01-01

22

Regulation of Biotin Transport in Saccharomyces Cerevisiae.  

National Technical Information Service (NTIS)

The metabolic control of biotin transport in Saccharomyces cerevisiae was investigated. Nonproliferating cells harvested from cultures grown in excess biotin (25 ng/ml) took up small amounts of biotin, whereas cells grown in biotin-sufficient medium (0.25...

T. O. Rogers, H. C. Lichstein

1969-01-01

23

INTERACTION BETWEEN SACCHAROMYCES CEREVISIAE AND CHRYSOTILE  

Microsoft Academic Search

The interaction between Saccharomyces cerevisiae and chrysotile fibers was studied by scanning electron microscopy. The yeast cells adhere preferentially to the fi- brils. In the extreme case, all the adhered fibrils were bro- ken, resulting in a complete coverage of the surface. The chrysotile covered cells showed less buds, but retained metabolic capacities, and were fully active in fermentation experiments

Flavia Cassiola; Marina Silveira; Soraya Jericó; Inés Joekes

24

Mcm2 and Mcm3 are constitutive nuclear proteins that exhibit distinct isoforms and bind chromatin during specific cell cycle stages of Saccharomyces cerevisiae.  

PubMed Central

The Mcm2-7 proteins are a family of conserved proteins whose functions are essential for the initiation of DNA synthesis in all eukaryotes. These patients are constitutively present in high abundance in actively proliferating cells. In Saccharomyces cerevisiae, the intracellular concentrations of Mcms are between 100 and 500 times the number of replication origins. However, these proteins are limiting for the initiation of DNA synthesis at replication origins. Our studies indicate that only a small fraction of Mcm2 and Mcm3 tightly associates with chromatin, from late M phase to the beginning of the S phase. The rest of the Mcm2 and Mcm3 proteins are disturbed to both the cytoplasm and nucleoplasm in relatively constant levels throughout the cell cycle. We also show that S. cerevisiae Mcm3 is a phosphoprotein that exists in multiple isoforms and that distinct isoforms of Mcm2 and Mcm3 can be detected at specific stages of the cell cycle. These results suggest that the localization and function of the Mcm proteins are regulated by posttranslational phosphorylation in a manner that is consistent with a role for the Mcm proteins in restricting DNA replication to once per cell cycle. Images PMID:9285827

Young, M R; Tye, B K

1997-01-01

25

Pseudouridine Mapping in the Saccharomyces cerevisiae Spliceosomal U Small Nuclear RNAs (snRNAs) Reveals that Pseudouridine Synthase Pus1p Exhibits a Dual Substrate Specificity for U2 snRNA and tRNA  

PubMed Central

Pseudouridine (?) residues were localized in the Saccharomyces cerevisiae spliceosomal U small nuclear RNAs (UsnRNAs) by using the chemical mapping method. In contrast to vertebrate UsnRNAs, S. cerevisiae UsnRNAs contain only a few ? residues, which are located in segments involved in intermolecular RNA-RNA or RNA-protein interactions. At these positions, UsnRNAs are universally modified. When yeast mutants disrupted for one of the several pseudouridine synthase genes (PUS1, PUS2, PUS3, and PUS4) or depleted in rRNA-pseudouridine synthase Cbf5p were tested for UsnRNA ? content, only the loss of the Pus1p activity was found to affect ? formation in spliceosomal UsnRNAs. Indeed, ?44 formation in U2 snRNA was abolished. By using purified Pus1p enzyme and in vitro-produced U2 snRNA, Pus1p is shown here to catalyze ?44 formation in the S. cerevisiae U2 snRNA. Thus, Pus1p is the first UsnRNA pseudouridine synthase characterized so far which exhibits a dual substrate specificity, acting on both tRNAs and U2 snRNA. As depletion of rRNA-pseudouridine synthase Cbf5p had no effect on UsnRNA ? content, formation of ? residues in S. cerevisiae UsnRNAs is not dependent on the Cbf5p-snoRNA guided mechanism. PMID:10022901

Massenet, Severine; Motorin, Yuri; Lafontaine, Denis L. J.; Hurt, Eduard C.; Grosjean, Henri; Branlant, Christiane

1999-01-01

26

Functional profiling of the Saccharomyces cerevisiae genome.  

PubMed

Determining the effect of gene deletion is a fundamental approach to understanding gene function. Conventional genetic screens exhibit biases, and genes contributing to a phenotype are often missed. We systematically constructed a nearly complete collection of gene-deletion mutants (96% of annotated open reading frames, or ORFs) of the yeast Saccharomyces cerevisiae. DNA sequences dubbed 'molecular bar codes' uniquely identify each strain, enabling their growth to be analysed in parallel and the fitness contribution of each gene to be quantitatively assessed by hybridization to high-density oligonucleotide arrays. We show that previously known and new genes are necessary for optimal growth under six well-studied conditions: high salt, sorbitol, galactose, pH 8, minimal medium and nystatin treatment. Less than 7% of genes that exhibit a significant increase in messenger RNA expression are also required for optimal growth in four of the tested conditions. Our results validate the yeast gene-deletion collection as a valuable resource for functional genomics. PMID:12140549

Giaever, Guri; Chu, Angela M; Ni, Li; Connelly, Carla; Riles, Linda; Véronneau, Steeve; Dow, Sally; Lucau-Danila, Ankuta; Anderson, Keith; André, Bruno; Arkin, Adam P; Astromoff, Anna; El-Bakkoury, Mohamed; Bangham, Rhonda; Benito, Rocio; Brachat, Sophie; Campanaro, Stefano; Curtiss, Matt; Davis, Karen; Deutschbauer, Adam; Entian, Karl-Dieter; Flaherty, Patrick; Foury, Francoise; Garfinkel, David J; Gerstein, Mark; Gotte, Deanna; Güldener, Ulrich; Hegemann, Johannes H; Hempel, Svenja; Herman, Zelek; Jaramillo, Daniel F; Kelly, Diane E; Kelly, Steven L; Kötter, Peter; LaBonte, Darlene; Lamb, David C; Lan, Ning; Liang, Hong; Liao, Hong; Liu, Lucy; Luo, Chuanyun; Lussier, Marc; Mao, Rong; Menard, Patrice; Ooi, Siew Loon; Revuelta, Jose L; Roberts, Christopher J; Rose, Matthias; Ross-Macdonald, Petra; Scherens, Bart; Schimmack, Greg; Shafer, Brenda; Shoemaker, Daniel D; Sookhai-Mahadeo, Sharon; Storms, Reginald K; Strathern, Jeffrey N; Valle, Giorgio; Voet, Marleen; Volckaert, Guido; Wang, Ching-yun; Ward, Teresa R; Wilhelmy, Julie; Winzeler, Elizabeth A; Yang, Yonghong; Yen, Grace; Youngman, Elaine; Yu, Kexin; Bussey, Howard; Boeke, Jef D; Snyder, Michael; Philippsen, Peter; Davis, Ronald W; Johnston, Mark

2002-07-25

27

Global Gene Response in Saccharomyces cerevisiae Exposed to Silver Nanoparticles  

Microsoft Academic Search

Silver nanoparticles (AgNPs), exhibiting a broad size range and morphologies with highly reactive facets, which are widely\\u000a applicable in real-life but not fully verified for biosafety and ecotoxicity, were subjected to report transcriptome profile\\u000a in yeast Saccharomyces cerevisiae. A large number of genes accounted for ?3% and ?5% of the genome affected by AgNPs and Ag-ions, respectively. Principal component\\u000a and

Javed H. Niazi; Byoung-In Sang; Yeon Seok Kim; Man Bock Gu

2011-01-01

28

Evidence for the Role of Recombination in the Regulatory Evolution of Saccharomyces cerevisiae Ty Elements  

E-print Network

Evidence for the Role of Recombination in the Regulatory Evolution of Saccharomyces cerevisiae Ty of the sequencing of the Saccharomyces cerevisiae genome provides a unique opportunity to analyze the evolutionary: Saccharomyces cerevisiae -- Ty -- Ret- rotransposons -- Regulatory evolution -- Recombina- tion Introduction

Jordan, King

29

Saccharomyces cerevisiae live cells stimulate degradation and fermentation of cellulose by the rumen anaerobic  

E-print Network

Saccharomyces cerevisiae live cells stimulate degradation and fermentation of cellulose France, 92300 Levallois-Perret, France Some live micro-organisms such as Saccharomyces cerevisiae). The effects of a Saccharomyces cerevisiae strain (SC) were investigated, in vitro, on degradation

Paris-Sud XI, Université de

30

GC content and recombination: reassessing the causal effects for the Saccharomyces cerevisiae genome  

E-print Network

1 GC content and recombination: reassessing the causal effects for the Saccharomyces cerevisiae: causality in yeast Keywords: recombination, Saccharomyces cerevisiae, GC content, biased gene conversion Saccharomyces cerevisiae, for which the most refined recombination data are available. First, we confirmed

Boyer, Edmond

31

Mechanisms of ethanol tolerance in Saccharomyces cerevisiae  

Microsoft Academic Search

Saccharomyces cerevisiae is a superb ethanol producer, yet is also sensitive to higher ethanol concentrations especially under high gravity or very\\u000a high gravity fermentation conditions. Ethanol tolerance is associated with interplay of complex networks at the genome level.\\u000a Although significant efforts have been made to study ethanol stress response in past decades, mechanisms of ethanol tolerance\\u000a are not well known.

Menggen Ma; Z. Lewis Liu

2010-01-01

32

Proteinase Mutants of SACCHAROMYCES CEREVISIAE  

PubMed Central

Fifty-nine mutants with reduced ability to cleave the chymotrypsin substrate N-acetyl-DL-phenylalanine ?-naphthyl ester have been isolated in S. cerevisiae. All have reduced levels of one or more of the three well-characterized proteinases in yeast. All have reduced levels of proteinase C (carboxy-peptidase Y). These mutations define 16 complementation groups. PMID:320092

Jones, Elizabeth W.

1977-01-01

33

A synthetic gene network for tuning protein degradation in Saccharomyces cerevisiae  

E-print Network

REPORT A synthetic gene network for tuning protein degradation in Saccharomyces cerevisiae Chris components of the Escherichia coli degradation machinery to construct a Saccharomyces cerevisiae strain

Hasty, Jeff

34

9806 Biochemistry 1994, 33, 9806-9812 Protein Carboxyl Methylation in Saccharomyces cerevisiae: Evidence for  

E-print Network

9806 Biochemistry 1994, 33, 9806-9812 Protein Carboxyl Methylation in Saccharomyces cerevisiae Received May 31, 1994' ABSTRACT: We incubated yeast cells (Saccharomyces cerevisiae) with the methyl donor

Hrycyna, Christine A.

35

Progress in Metabolic Engineering of Saccharomyces cerevisiae  

PubMed Central

Summary: The traditional use of the yeast Saccharomyces cerevisiae in alcoholic fermentation has, over time, resulted in substantial accumulated knowledge concerning genetics, physiology, and biochemistry as well as genetic engineering and fermentation technologies. S. cerevisiae has become a platform organism for developing metabolic engineering strategies, methods, and tools. The current review discusses the relevance of several engineering strategies, such as rational and inverse metabolic engineering, evolutionary engineering, and global transcription machinery engineering, in yeast strain improvement. It also summarizes existing tools for fine-tuning and regulating enzyme activities and thus metabolic pathways. Recent examples of yeast metabolic engineering for food, beverage, and industrial biotechnology (bioethanol and bulk and fine chemicals) follow. S. cerevisiae currently enjoys increasing popularity as a production organism in industrial (“white”) biotechnology due to its inherent tolerance of low pH values and high ethanol and inhibitor concentrations and its ability to grow anaerobically. Attention is paid to utilizing lignocellulosic biomass as a potential substrate. PMID:18772282

Nevoigt, Elke

2008-01-01

36

Comprehensive polymorphism survey elucidates population structure of Saccharomyces cerevisiae  

E-print Network

a nucleotide-level survey of genomic variation in a diverse collection of 63 Saccharomyces cerevisiae strainsLETTERS Comprehensive polymorphism survey elucidates population structure of Saccharomyces cerevisiae Joseph Schacherer1 *{, Joshua A. Shapiro1 *, Douglas M. Ruderfer1 & Leonid Kruglyak1 Comprehensive

Kruglyak, Leonid

37

Sporulation in the Budding Yeast Saccharomyces cerevisiae  

PubMed Central

In response to nitrogen starvation in the presence of a poor carbon source, diploid cells of the yeast Saccharomyces cerevisiae undergo meiosis and package the haploid nuclei produced in meiosis into spores. The formation of spores requires an unusual cell division event in which daughter cells are formed within the cytoplasm of the mother cell. This process involves the de novo generation of two different cellular structures: novel membrane compartments within the cell cytoplasm that give rise to the spore plasma membrane and an extensive spore wall that protects the spore from environmental insults. This article summarizes what is known about the molecular mechanisms controlling spore assembly with particular attention to how constitutive cellular functions are modified to create novel behaviors during this developmental process. Key regulatory points on the sporulation pathway are also discussed as well as the possible role of sporulation in the natural ecology of S. cerevisiae. PMID:22084423

Neiman, Aaron M.

2011-01-01

38

Assessing chronological Aging in Saccharomyces cerevisiae  

PubMed Central

Saccharomyces cerevisiae is one of the most studied model organisms for the identification of genes and mechanisms that affect aging. The chronological lifespan (CLS) assay which monitors the survival of a non-dividing population, is one of the two methods to study aging in yeast. To eliminate potential artifacts and identify genes and signaling pathways that may also affect aging in higher eukaryotes, it is important to determine CLS by multiple methods. Here, we describe these methods as well as the assays to study macromolecular damage during aging in yeast, with a focus on genomic instability. PMID:23296677

Hu, Jia; Wei, Min; Mirisola, Mario G.; Longo, Valter D.

2014-01-01

39

YEAST VOL. 11: 1275-1280 (1995) Precise Gene Disruption in Saccharomyces cerevisiae by  

E-print Network

YEAST VOL. 11: 1275-1280 (1995) Precise Gene Disruption in Saccharomyces cerevisiae by Double in Saccharomyces cerevisiae. KEY WORDS ~ gene disruption; fusion PCR; Saccharomyces cerevisiae INTRODUCTIONUCl8: pJJ215 (bearing the HIS3 #12;1276 Table 1. Saccharomyces cerevisiae strains. D. C. AMBERG ET AL

Botstein, David

40

Biodiversity study of wine yeasts belonging to the "terroir" of Montepulciano d'Abruzzo "Colline Teramane" revealed Saccharomyces cerevisiae strains exhibiting atypical and unique 5.8S-ITS restriction patterns.  

PubMed

The Montepulciano d'Abruzzo "Colline Teramane" premium wine DOCG is produced in the Teramo province (Abruzzo, Italy). This region has a great tradition in winemaking and the wine is produced by a spontaneous fermentation so it could represent a reservoir of wine natural yeasts with important oenological features. The aim of this study was to characterize the yeast community of this wine grape growing region in order to create a Saccharomyces cerevisiae bank, providing data on oenological properties for potential industrial applications. A total of 430 yeasts were isolated at the end of spontaneous fermentation. PCR-RFLP was applied for the identification at the species level and underlined that 14 strains exhibited unusual and characteristic restriction patterns different from those typical of the species S. cerevisiae. This difference was due to the insertion of base C at a position 138 in the ITS1 region that determined an additional cleavage site for the enzyme HaeIII. This insertion could be associated to the fermentative performance and associated to the relationship existing between yeasts and a viticulture region or 'terroir'. PMID:24387846

Tofalo, Rosanna; Perpetuini, Giorgia; Fasoli, Giuseppe; Schirone, Maria; Corsetti, Aldo; Suzzi, Giovanna

2014-05-01

41

Single QTLmapping and nucleotide-level resolution ofa physiologic trait in wine Saccharomyces cerevisiae strains  

E-print Network

microarray; aneuploidy; ASP1 ; wine fermentation. Abstract Natural Saccharomyces cerevisiae yeast strains et al., 2004). Metabolic pathways have been extensively dissected in Saccharomyces cerevisiaeSingle QTLmapping and nucleotide-level resolution ofa physiologic trait in wine Saccharomyces

Paris-Sud XI, Université de

42

Enhanced Arsenate Uptake in Saccharomyces cerevisiae Overexpressing the Pho84 Phosphate Transporter  

E-print Network

Enhanced Arsenate Uptake in Saccharomyces cerevisiae Overexpressing the Pho84 Phosphate Transporter Keywords: arsenate, PHO84, ADH2, Saccharomyces cerevisiae, bioremediation Introduction Drinking water- ces cerevisiae was engineered as a potential biosorbent for enhanced arsenate accumulation

Chen, Wilfred

43

Identification of the mitochondrial pyruvate carrier in Saccharomyces cerevisiae.  

PubMed Central

Mitochondrial pyruvate transport is fundamental for metabolism and mediated by a specific inhibitable carrier. We have identified the yeast mitochondrial pyruvate carrier by measuring inhibitor-sensitive pyruvate uptake into mitochondria from 18 different Saccharomyces cerevisiae mutants, each lacking an unattributed member of the mitochondrial carrier family (MCF). Only mitochondria from the YIL006w deletion mutant exhibited no inhibitor-sensitive pyruvate transport, but otherwise behaved normally. YIL006w encodes a 41.9 kDa MCF member with homologous proteins present in both the human and mouse genomes. PMID:12887330

Hildyard, John C W; Halestrap, Andrew P

2003-01-01

44

Myo-inositol transport in Saccharomyces cerevisiae.  

PubMed Central

myo-Inositol uptake in Saccharomyces cerevisiae was dependent on temperature, time, and substrate concentration. The transport obeyed saturation kinetics with an apparent Km for myo-inositol of 0.1 mM, myo-Inositol analogs, such as scyllo-inositol, 2-inosose, mannitol, and 1,2-cyclohexanediol, had no effect on myo-inositol uptake, myo-Inositol uptake required metabolic energy. Removal of D-glucose resulted in a loss of activity, and azide and cyanide ions were inhibitory. In the presence of D-glucose, myo-inositol was accumulated in the cells against a concentration gradient. A myo-inositol transport mutant was isolated from UV-mutagenized S. cerevisiae cells using the replica-printing technique. The defect in myo-inositol uptake was due to a single nuclear gene mutation. The activities of L-serine and D-glucose transport were not affected by the mutation. Thus it was shown that S. cerevisiae grown under the present culture conditions possessed a single and specific myo-inositol transport system. myo-Inositol transport activity was reduced by the addition of myo-inositol to the culture medium. The activity was reversibly restored by the removal of myo-inositol from the medium. This restoration of activity was completely abolished by cycloheximide. Images PMID:7040334

Nikawa, J; Nagumo, T; Yamashita, S

1982-01-01

45

Polyamine auxotrophs of Saccharomyces cerevisiae.  

PubMed Central

Strains of yeast have been constructed that are unable to synthesize ornithine and are thereby deficient in polyamine biosynthesis. These strains were used to develop a protocol for isolation of mutants blocked directly in polyamine synthesis. There were seven mutants isolated that lack ornithine decarboxylase activity; these strains exhibited greatly decreased pool levels of putrescine, spermidine, and spermine when grown in the absence of polyamines. Three of the mutants lack S-adenosylmethionine decarboxylase activity; polyamine limitation of a representative mutant resulted in an accumulation of putrescine and a decrease in spermidine and spermine. When the mutants were cultured in the absence of polyamines, a continuously declining growth rate was observed. Images PMID:348679

Whitney, P A; Morris, D R

1978-01-01

46

Autonomously replicating sequences in Saccharomyces cerevisiae.  

PubMed Central

A method is presented for isolating DNA segments capable of autonomous replication from Saccharomyces cerevisiae chromosomal DNA based on the differential transforming ability of autonomously replicating plasmids and nonreplicating plasmids. DNA plasmids that are capable of self-replication in yeast transform yeast spheroplasts at about 1000-fold higher frequency than nonreplicating plasmids. We have cloned from total yeast DNA a number of DNA segments that permit the pBR322 plasmid carrying the yeast LEU2 gene to replicate autonomously. These plasmid clones are characterized by their ability to transform Leu- spheroplasts to Leu+ at a high frequency and their ability to replicate autonomously. Analysis of the insert DNAs carried in some of these self-replicating plasmids divides them into two categories: those that are unique in the yeast genome and those that are repetitive. Images PMID:7005897

Chan, C S; Tye, B K

1980-01-01

47

Characterization of the Biotin Transport System in Saccharomyces Cerevisiae.  

National Technical Information Service (NTIS)

The characteristics of the biotin transport mechanism of Saccharomyces cerevisiae were investigated in nonproliferating cells. Microbiological and radioisotope assays were employed to measure biotin uptake. The vitamin existed intracellularly in both free...

T. O. Rogers, H. C. Lichstein

1969-01-01

48

Composition and Formation of the Saccharomyces cerevisiae Centromeric Nucleosome  

E-print Network

The kinetochore is a complex, multi-protein structure required for proper chromosome segregation in all eukaryotes. The Saccharomyces cerevisiae kinetochore consists of over 65 known proteins which work in concert to facilitate equal distribution...

Camahort, Raymond Anthony

2008-01-01

49

Effect of a Saccharomyces cerevisiae culture on growth and lactate utilization by the ruminal  

E-print Network

Note Effect of a Saccharomyces cerevisiae culture on growth and lactate utilization by the ruminal/ Saccharomyces cerevisiae Résumé — Effet d'une culture de Saccharomyces cerevisiae sur la croissance et l- denii augmente. utilisation du lactatelcroissance bactérienne/Megasphaera elsdenü /Saccharomyces

Paris-Sud XI, Université de

50

Survival kit of Saccharomyces cerevisiae for anhydrobiosis.  

PubMed

Yeast cells are well adapted to interfacial habitats, such as the surfaces of soil or plants, where they can resist frequent fluctuations between wet and dry conditions. Saccharomyces cerevisiae is recognized as an anhydrobiotic organism, and it has been the subject of numerous studies that aimed to elucidate this ability. Extensive data have been obtained from these studies based on a wide range of experimental approaches, which have added significantly to our understanding of the cellular bases and mechanisms of resistance to desiccation. The aim of this review is to provide an integrated view of these mechanisms in yeast and to describe the survival kit of S. cerevisiae for anhydrobiosis. This kit comprises constitutive and inducible mechanisms that prevent cell damage during dehydration and rehydration. This review also aims to characterize clearly the phenomenon of anhydrobiosis itself based on detailed descriptions of the causes and effects of the constraints imposed on cells by desiccation. These constraints mainly lead to mechanical, structural, and oxidative damage to cell components. Considerations of these constraints and the possible utilization of components of the survival kit could help to improve the survival of sensitive cells of interest during desiccation. PMID:25172136

Dupont, Sebastien; Rapoport, Alexander; Gervais, Patrick; Beney, Laurent

2014-11-01

51

In vitro screening of probiotic properties of Saccharomyces cerevisiae var. boulardii and food-borne Saccharomyces cerevisiae strains  

Microsoft Academic Search

The probiotic potential of 18 Saccharomyces cerevisiae strains used for production of foods or beverages or isolated from such, and eight strains of Saccharomyces cerevisiae var. boulardii, was investigated. All strains included were able to withstand pH 2.5 and 0.3% Oxgall. Adhesion to the nontumorigenic porcine jejunal epithelial cell line (IPEC-J2) was investigated by incorporation of 3H-methionine into the yeast

Alis van der Aa Kühle; Kerstin Skovgaard; Lene Jespersen

2005-01-01

52

Analyzing Fuzzy Partitions of Saccharomyces Cerevisiae Cell-Cycle Gene Expression Data by  

E-print Network

Analyzing Fuzzy Partitions of Saccharomyces Cerevisiae Cell-Cycle Gene Expression Data by Bayesian profiles, fuzzy clustering, Bayesian validation method, Saccharomyces cerwisiae cell cyclegeneerpression

Cho, Sung-Bae

53

An assay for functional xylose transporters in Saccharomyces cerevisiae.  

PubMed

It has been considered that more efficient uptake of xylose could promote increased xylose metabolic capacity of several microorganisms. In this study, an assay to screen xylose transporters was established in the Saccharomyces cerevisiae strain, which expresses the xylosidase gene of Bacillus pumilus intracellularly. The absorbed xylose analog p-nitrophenyl-?-d-xylopyranoside (pNPX) rapidly hydrolyzed to p-nitrophenol (pNP), which displayed a yellow tint when exposed to xylosidase in vivo. The xylose transporter activities of the strain were computed using the pNP production rate, which was detected extracellularly. This method could be used for both high-throughput screening and smaller scale investigations. AraEp, which is a pentose transporter of Corynebacterium glutamicum, was expressed in S. cerevisiae and exhibited better transport capacity than the endogenous transporters Hxt7p and Gal2p. Moreover, a mutant of AraEp with 103% greater transport capacity was screened out, and the computer simulation suggested that transmembrane domain 5 was an important factor for the transport capacity of AraEp in S. cerevisiae. PMID:23928049

Wang, Chengqiang; Shen, Yu; Hou, Jin; Suo, Fan; Bao, Xiaoming

2013-11-15

54

The flavoproteome of the yeast Saccharomyces cerevisiae?  

PubMed Central

Genome analysis of the yeast Saccharomyces cerevisiae identified 68 genes encoding flavin-dependent proteins (1.1% of protein encoding genes) to which 47 distinct biochemical functions were assigned. The majority of flavoproteins operate in mitochondria where they participate in redox processes revolving around the transfer of electrons to the electron transport chain. In addition, we found that flavoenzymes play a central role in various aspects of iron metabolism, such as iron uptake, the biogenesis of iron–sulfur clusters and insertion of the heme cofactor into apocytochromes. Another important group of flavoenzymes is directly (Dus1-4p and Mto1p) or indirectly (Tyw1p) involved in reactions leading to tRNA-modifications. Despite the wealth of genetic information available for S. cerevisiae, we were surprised that many flavoproteins are poorly characterized biochemically. For example, the role of the yeast flavodoxins Pst2p, Rfs1p and Ycp4p with regard to their electron donor and acceptor is presently unknown. Similarly, the function of the heterodimeric Aim45p/Cir1p, which is homologous to the electron-transferring flavoproteins of higher eukaryotes, in electron transfer processes occurring in the mitochondrial matrix remains to be elucidated. This lack of information extends to the five membrane proteins involved in riboflavin or FAD transport as well as FMN and FAD homeostasis within the yeast cell. Nevertheless, several yeast flavoproteins, were identified as convenient model systems both in terms of their mechanism of action as well as structurally to improve our understanding of diseases caused by dysfunctional human flavoprotein orthologs. PMID:24373875

Gudipati, Venugopal; Koch, Karin; Lienhart, Wolf-Dieter; Macheroux, Peter

2014-01-01

55

Recognition of a conserved class of RNA tetraloops by Saccharomyces cerevisiae RNase III  

E-print Network

Recognition of a conserved class of RNA tetraloops by Saccharomyces cerevisiae RNase III Guillaume with the bacterial enzyme (6­8). Since its discovery, Saccharomyces cerevisiae RNase III (Rnt1p) has been shown

Chanfreau, Guillaume

56

Stimulation of RTH1 Nuclease of the Yeast Saccharomyces cereVisiae by Replication Protein A  

E-print Network

Stimulation of RTH1 Nuclease of the Yeast Saccharomyces cereVisiae by Replication Protein A Esther-stranded circular DNA as a template. The RAD2 gene product of the yeast Saccharomyces cereVisiae has been shown

Ronquist, Fredrik

57

Predicting the Evolution of Gene ura3 in the Yeast Saccharomyces Cerevisiae  

E-print Network

Predicting the Evolution of Gene ura3 in the Yeast Saccharomyces Cerevisiae Jacques M. Bahi1 Saccharomyces cerevisiae. Using this experimental study, authors of this paper have deduced a simple mutation

Paris-Sud XI, Université de

58

Comparative effects of Saccharomyces cerevisiae and Aspergillus oryzae on rumen fermentations  

E-print Network

Comparative effects of Saccharomyces cerevisiae and Aspergillus oryzae on rumen fermentations F Aubière Cedex, France Saccharomyces cerevisiae (SC) and Aspergillus oryzae (AO) have both been proposed

Boyer, Edmond

59

Ferric Reductase of Saccharomyces cerevisiae: Molecular Characterization, Role in Iron Uptake, and Transcriptional Control by Iron  

Microsoft Academic Search

The principal iron uptake system of Saccharomyces cerevisiae utilizes a reductase activity that acts on ferric iron chelates external to the cell. The FRE1 gene product is required for this activity. The deduced amino acid sequence of the FRE1 protein exhibits hydrophobic regions compatible with transmembrane domains and has significant similarity to the sequence of the plasma membrane cytochrome b558

Andrew Dancis; Dragos G. Roman; Gregory J. Anderson; Alan G. Hinnebusch; Richard D. Klausner

1992-01-01

60

Stationary phase in the yeast Saccharomyces cerevisiae.  

PubMed Central

Growth and proliferation of microorganisms such as the yeast Saccharomyces cerevisiae are controlled in part by the availability of nutrients. When proliferating yeast cells exhaust available nutrients, they enter a stationary phase characterized by cell cycle arrest and specific physiological, biochemical, and morphological changes. These changes include thickening of the cell wall, accumulation of reserve carbohydrates, and acquisition of thermotolerance. Recent characterization of mutant cells that are conditionally defective only for the resumption of proliferation from stationary phase provides evidence that stationary phase is a unique developmental state. Strains with mutations affecting entry into and survival during stationary phase have also been isolated, and the mutations have been shown to affect at least seven different cellular processes: (i) signal transduction, (ii) protein synthesis, (iii) protein N-terminal acetylation, (iv) protein turnover, (v) protein secretion, (vi) membrane biosynthesis, and (vii) cell polarity. The exact nature of the relationship between these processes and survival during stationary phase remains to be elucidated. We propose that cell cycle arrest coordinated with the ability to remain viable in the absence of additional nutrients provides a good operational definition of starvation-induced stationary phase. PMID:8393130

Werner-Washburne, M; Braun, E; Johnston, G C; Singer, R A

1993-01-01

61

Genome-Wide Analysis of Nucleotide-Level Variation in Commonly Used Saccharomyces cerevisiae Strains  

E-print Network

Genome-Wide Analysis of Nucleotide-Level Variation in Commonly Used Saccharomyces cerevisiae of Saccharomyces cerevisiae­more precisely, the S288c strain­was completely sequenced. However, experimental work and redundant coverage of the ,12 Mb Saccharomyces cerevisiae genome. Using these data, we assessed

Kruglyak, Leonid

62

A Conserved Major Groove Antideterminant for Saccharomyces cereVisiae RNase III Recognition  

E-print Network

A Conserved Major Groove Antideterminant for Saccharomyces cereVisiae RNase III Recognition Mui Sam, 2004; ReVised Manuscript ReceiVed January 10, 2005 ABSTRACT: Rnt1p, the only known Saccharomyces cereVisiae roles in the processing of other stable small RNAs. In Saccharomyces cereVisiae, the U1, U2, U4, and U5

Chanfreau, Guillaume

63

Computational identication of non-coding RNAs in Saccharomyces cerevisiae by comparative genomics  

E-print Network

Computational identi®cation of non-coding RNAs in Saccharomyces cerevisiae by comparative genomics-coding RNAs (ncRNAs) in the genome sequence of the yeast Saccharomyces cerevisiae using computational (5±17). The budding yeast Saccharomyces cerevisiae is one of the most powerful model systems

Eddy, Sean

64

Pathway redundancy and protein essentiality revealed in the Saccharomyces cerevisiae interaction networks  

E-print Network

REPORT Pathway redundancy and protein essentiality revealed in the Saccharomyces cerevisiae on a large-scale Saccharomyces cerevisiae data set, our analysis reveals 140 between-pathway models shown that only B18% of Saccharomyces cerevisiae genes are essential for growth on a rich medium

Shamir, Ron

65

Manifold anomalies in gene expression in a vineyard isolate of Saccharomyces cerevisiae revealed by  

E-print Network

Manifold anomalies in gene expression in a vineyard isolate of Saccharomyces cerevisiae revealed of Saccharomyces cerevisiae isolated from wine grapes in a Tuscan vineyard, along with the diploid progeny obtained in parent and progeny of a natural isolate of Saccharomyces cerevisiae cultured under standard conditions

Hartl, Daniel L.

66

Discovery of Recurrent Sequence Motifs in Saccharomyces cerevisiae Cell Wall Proteins  

E-print Network

Discovery of Recurrent Sequence Motifs in Saccharomyces cerevisiae Cell Wall Proteins Juan E in a set of 171 known and putative cell wall proteins from baker's yeast, Saccharomyces cerevisiae Saccharomyces cerevisiae (bakers' yeast) and the visually-oriented methods used to find them. The evolutionary

Epstein, Susan L.

67

Structural Characterization of the Saccharomyces cerevisiae THO Complex by Small-Angle X-Ray Scattering  

E-print Network

Structural Characterization of the Saccharomyces cerevisiae THO Complex by Small-Angle X-competent messenger ribonucleoprotein particles. In Saccharomyces cerevisiae, THO has been defined as a heteropentamer of the Saccharomyces cerevisiae THO Complex by Small-Angle X-Ray Scattering. PLoS ONE 9(7): e103470. doi:10

Schierup, Mikkel Heide

68

Regulation of the Saccharomyces cerevisiae CKI1-encoded Choline Kinase by Zinc Depletion*  

E-print Network

Regulation of the Saccharomyces cerevisiae CKI1-encoded Choline Kinase by Zinc Depletion* Received Saccharomyces cerevisiae, the CKI1-encoded cho- line kinase catalyzes the committed step in the synthesis Saccharomyces cer- evisiae (1). Zinc is an essential mineral for the growth and metabolism of S. cerevisiae

Chen, Kuang-Yu

69

Computational identification of non-coding RNAs in Saccharomyces cerevisiae by comparative genomics  

E-print Network

1 Computational identification of non-coding RNAs in Saccharomyces cerevisiae by comparative systems amenable to genetic and biochemical analysis (5-16). The budding yeast Saccharomyces cerevisiae Saccharomyces genomic data to perform a QRNA screen for new structural ncRNA genes in S. cerevisiae. Materials

Eddy, Sean

70

Evolution of Microsatellites in the Yeast Saccharomyces cerevisiae: Role of Length and Number of Repeated Units  

E-print Network

Evolution of Microsatellites in the Yeast Saccharomyces cerevisiae: Role of Length and Number. The observed and expected frequencies of occurrence of microsatellites in the yeast Saccharomyces cerevisiae taken from the Saccharomyces cerevisiae database (Goffeau et al. 1997). The mononucleotides were counted

Pupko, Tal

71

Genome-Scale Analysis of Saccharomyces cerevisiae Metabolism and Ethanol Production  

E-print Network

ARTICLE Genome-Scale Analysis of Saccharomyces cerevisiae Metabolism and Ethanol Production in Fed Periodicals, Inc. KEYWORDS: Saccharomyces cerevisiae; dynamic flux bal- ance analysis; genome-scale metabolic targets that are experimen- tally testable. In a recent study with a Saccharomyces cerevisiae genome

Mountziaris, T. J.

72

Regulation of Cation Balance in Saccharomyces cerevisiae  

PubMed Central

All living organisms require nutrient minerals for growth and have developed mechanisms to acquire, utilize, and store nutrient minerals effectively. In the aqueous cellular environment, these elements exist as charged ions that, together with protons and hydroxide ions, facilitate biochemical reactions and establish the electrochemical gradients across membranes that drive cellular processes such as transport and ATP synthesis. Metal ions serve as essential enzyme cofactors and perform both structural and signaling roles within cells. However, because these ions can also be toxic, cells have developed sophisticated homeostatic mechanisms to regulate their levels and avoid toxicity. Studies in Saccharomyces cerevisiae have characterized many of the gene products and processes responsible for acquiring, utilizing, storing, and regulating levels of these ions. Findings in this model organism have often allowed the corresponding machinery in humans to be identified and have provided insights into diseases that result from defects in ion homeostasis. This review summarizes our current understanding of how cation balance is achieved and modulated in baker’s yeast. Control of intracellular pH is discussed, as well as uptake, storage, and efflux mechanisms for the alkali metal cations, Na+ and K+, the divalent cations, Ca2+ and Mg2+, and the trace metal ions, Fe2+, Zn2+, Cu2+, and Mn2+. Signal transduction pathways that are regulated by pH and Ca2+ are reviewed, as well as the mechanisms that allow cells to maintain appropriate intracellular cation concentrations when challenged by extreme conditions, i.e., either limited availability or toxic levels in the environment. PMID:23463800

Cyert, Martha S.; Philpott, Caroline C.

2013-01-01

73

RESEARCH ARTICLE Catalase enzyme in mitochondria of Saccharomyces cerevisiae  

E-print Network

Catalase and superoxide dismutase activities have been explored in the yeast Saccharomyces cerevisiae during batchwise growth experiment. During the diauxic growth in YPD medium high Ys values were obtained (0.415- 0.423) and correlation between the total activities of both enzymes has been found. A mitochondrial fraction from three type strains of Saccharomyces cerevisiae has been isolated. The purity of this fraction was proved through different enzyme assays: hexokinase, glucose-6-phosphate dehydrogenase, D-amino acid oxidase, isocitric lyase, succinate dehydrogenase. Then the catalase, peroxidase, Mn and Cu/Zn superoxide dismutase activities were evaluated in the mitochondrial fraction. Polyacrylamide gel electrophoresis separations allowed to identify a

Ventsislava Yankova Petrova; Tanya Vassileva Rasheva; Anna V. Kujumdzieva

2002-01-01

74

Invasive Saccharomyces cerevisiae infection: A friend turning foe?  

PubMed

We report a very rare case of acute pyelonephritis in a 51-year-old female with a history of chronic kidney disease (CKD) and diabetes caused by a normally benign and a well-known human commensal organism, Saccharomyces cerevisiae that is very often prescribed as a probiotic in modern medical practice. The causal role of S. cerevisiae was confirmed by its isolation in blood, urine, stool as well as vaginal swabs thus proving its virulent nature in suitable situations. PMID:25394448

Pillai, Unnikrishnan; Devasahayam, Joe; Kurup, Aparna Narayana; Lacasse, Alexandre

2014-01-01

75

Physiological effects of 5-hydroxymethylfurfural on Saccharomyces cerevisiae  

Microsoft Academic Search

The physiological effects of 5-hydroxymethylfurfural (HMF) on Saccharomyces cerevisiae CBS 8066 in the presence and absence of furfural were studied. Experiments were carried out by pulse addition of HMF (2–4?g\\/l)\\u000a as well as HMF (2?g\\/l) together with furfural (2?g\\/l) to batch cultivations of S. cerevisiae. Synthetic medium with glucose (50?g\\/l) as carbon and energy source was used. Addition of 4?g\\/l

M. J. Taherzadeh; L. Gustafsson; C. Niklasson; G. Lidén

2000-01-01

76

Purification and Characterization of Put1p from Saccharomyces cerevisiae  

PubMed Central

In Saccharomyces cerevisiae, the PUT1 and PUT2 genes are required for the conversion of proline to glutamate. The PUT1 gene encodes Put1p, a proline dehydrogenase (PRODH)1 enzyme localized in the mitochondrion. Put1p was expressed and purified from Escherichia coli and shown to have a UV-visible absorption spectrum that is typical of a bound flavin cofactor. A Km value of 36 mM proline and a kcat = 27 s?1 were determined for Put1p using an artificial electron acceptor. Put1p also exhibited high activity using ubiquinone-1 (CoQ1) as an electron acceptor with a kcat = 9.6 s?1 and a Km of 33 µM for CoQ1. In addition, knockout strains of the electron transfer flavoprotein (ETF) homolog in S. cerevisiae were able to grow on proline as the sole nitrogen source demonstrating that ETF is not required for proline utilization in yeast. PMID:20450881

Wanduragala, Srimevan; Sanyal, Nikhilesh; Liang, Xinwen; Becker, Donald F.

2010-01-01

77

Modelling neurodegeneration in Saccharomyces cerevisiae: why cook with baker's yeast?  

Microsoft Academic Search

In ageing populations, neurodegenerative diseases increase in prevalence, exacting an enormous toll on individuals and their communities. Multiple complementary experimental approaches are needed to elucidate the mechanisms underlying these complex diseases and to develop novel therapeutics. Here, we describe why the budding yeast Saccharomyces cerevisiae has a unique role in the neurodegeneration armamentarium. As the best-understood and most readily analysed

Vikram Khurana; Susan Lindquist

2010-01-01

78

Biolistic nuclear transformation of Saccharomyces cerevisiae and other fungi  

Microsoft Academic Search

Tungsten microprojectiles coated with nucleic acid and accelerated to velocities of approximately 500 m\\/s, can penetrate living cells and tissues with consequent expression of the introduced genes (Klein et al. 1987). Saccharomyces cerevisiae is used here as a model system to define the basic parameters governing the biolistic (biological-ballistic) delivery of DNA into cells. Among the physical factors affecting the

Daniele Armaleo; Guang-Ning Ye; Theodore M. Klein; Katherine B. Shark; John C. Sanford; Stephen Albert Johnston

1990-01-01

79

The Quaternary Structure of the Saccharomyces cerevisiae Succinate Dehydrogenase  

Microsoft Academic Search

Succinate dehydrogenases and fumarate reductases are complex mitochondrial or bacterial respiratory chain proteins with remarkably similar structures and functions. Succinate dehydrogenase oxidizes succinate and reduces ubiquinone using a flavin adenine dinucle- otide cofactor and iron-sulfur clusters to transport elec- trons. A model of the quaternary structure of the tetrameric Saccharomyces cerevisiae succinate dehydrogenase was constructed based on the crystal structures

Kayode S. Oyedotun; Bernard D. Lemire

80

Complete Nucleotide Sequence of Saccharomyces cerevisiae Chromosome VIII  

Microsoft Academic Search

The complete nucleotide sequence of Saccharomyces cerevisiae chromosome VIII reveals that it contains 269 predicted or known genes (300 base pairs or larger). Fifty-nine of these genes (22 percent) were previously identified. Of the 210 novel genes, 65 are predicted to encode proteins that are similar to other proteins of known or predicted function. Sixteen genes appear to be relatively

M. Johnston; S. Andrews; R. Brinkman; J. Cooper; H. Ding; J. Dover; Z. Du; A. Favello; L. Fulton; S. Gattung; C. Geisel; J. Kirsten; T. Kucaba; L. Hillier; M. Jier; L. Johnston; Y. Langston; P. Latreille; E. J. Louis; C. Macri; E. Mardis; S. Menezes; L. Mouser; M. Nhan; L. Rifkin; L. Riles; H. St. Peter; E. Trevaskis; K. Vaughan; D. Vignati; L. Wilcox; P. Wohldman; R. Waterston; R. Wilson; M. Vaudin

1994-01-01

81

Genome-Scale Reconstruction of the Saccharomyces cerevisiae Metabolic Network  

Microsoft Academic Search

The metabolic network in the yeast Saccharomyces cerevisiae was reconstructed using currently available genomic, biochemical, and physiological information. The metabolic reactions were compartmentalized between the cytosol and the mitochondria, and transport steps between the compartments and the environment were included. A total of 708 structural open reading frames (ORFs) were accounted for in the reconstructed network, corresponding to 1035 metabolic

Jochen Forster; Iman Famili; Patrick Fu; Bernhard Ø; Jens Nielsen

2003-01-01

82

Hierarchical Bayesian Modelling for Saccharomyces cerevisiae population dynamics  

Microsoft Academic Search

Hierarchical Bayesian Modelling is powerful however under-used to model and evaluate the risks associated with the development of pathogens in food industry, to predict exotic invasions, species extinctions and development of emerging diseases, or to assess chemical risks. Modelling population dynamics of Saccharomyces cerevisiae considering its biodiversity and other sources of variability is crucial for selecting strains meeting industrial needs.

Aymé Spor; Christine Dillmann; Shaoxiao Wang; Dominique de Vienne; Delphine Sicard; Eric Parent

2010-01-01

83

Production of lipid compounds in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

This review describes progress using the yeast Saccharomyces cerevisiae as a model organism for the fast and efficient analysis of genes and enzyme activities involved in the lipid biosynthetic pathways of several donor organisms. Furthermore, we assess the impact of baker's yeast on the production of novel, high-value lipid compounds. Yeast can be genetically modified to produce selected substances in

M. Veen; C. Lang

2004-01-01

84

Glucose Metabolism in gcr Mutants of Saccharomyces cerevisiae  

PubMed Central

A gcr2 null mutant of Saccharomyces cerevisiae grows well on glucose in spite of its lower level of glycolytic enzymes between triose phosphates and pyruvate. A quantitative analysis shows that these levels are adequate to the flux but glycerate phosphates are elevated. PMID:10419980

Uemura, H.; Fraenkel, D. G.

1999-01-01

85

Analysis of the RNA Content of the Yeast "Saccharomyces Cerevisiae"  

ERIC Educational Resources Information Center

In this article, the authors describe an interconnected set of relatively simple laboratory experiments in which students determine the RNA content of yeast cells and use agarose gel electrophoresis to separate and analyze the major species of cellular RNA. This set of experiments focuses on RNAs from the yeast "Saccharomyces cerevisiae", a…

Deutch, Charles E.; Marshall, Pamela A.

2008-01-01

86

Genetic and Physical Interactions between Tel2 and the Med15 Mediator Subunit in Saccharomyces cerevisiae  

E-print Network

Interactions between Tel2 and the Med15 Mediator Subunit in Saccharomyces cerevisiae. PLoS ONE 7(1): e30451 of telomere length in the budding yeast Saccharomyces cerevisiae, but became eventually, over twenty yearsGenetic and Physical Interactions between Tel2 and the Med15 Mediator Subunit in Saccharomyces

Paris-Sud XI, Université de

87

A cotranscriptional model for 3 -end processing of the Saccharomyces cerevisiae pre-ribosomal RNA precursor  

E-print Network

A cotranscriptional model for 3 -end processing of the Saccharomyces cerevisiae pre-ribosomal RNA, France ABSTRACT Cleavage of the Saccharomyces cerevisiae primary ribosomal RNA (rRNA) transcript in the 3 a typical nuclease domain con- taining the RNase III signature motif. The genome of the yeast Saccharomyces

Chanfreau, Guillaume

88

Repetitive sequence variation and dynamics in the ribosomal DNA array of Saccharomyces cerevisiae as  

E-print Network

in high copy numbers. In the baker's yeast Saccharomyces cerevisiae, there are more than 100 rDNA repeats is available online at www.genome.org.] In the baker's yeast Saccharomyces cerevisiae, the rDNA array, whichLetter Repetitive sequence variation and dynamics in the ribosomal DNA array of Saccharomyces

van Oudenaarden, Alexander

89

Import of alcohol oxidase into peroxisomes of Saccharomyces cerevisiae.  

PubMed Central

Saccharomyces cerevisiae is unable to grow on methanol because it lacks the enzymes required for its metabolism. To study the possibility of whether or not the methanol oxidation pathway of Hansenula polymorpha can be transferred to S. cerevisiae, the gene coding for alcohol oxidase, a peroxisomal homo-octameric flavoprotein, was introduced into S. cerevisiae. Transformed cells contain varying amounts of alcohol oxidase depending on the plasmid used. Immunocytochemical experiments indicate that the protein is imported into peroxisomes, whether organelle proliferation is induced or not. Cells lack alcohol oxidase activity however, and only the monomeric, non-functional, form of the protein is found. These findings indicate that the H. polymorpha peroxisomal targeting signal of alcohol oxidase is recognized in S. cerevisiae and protein monomers are imported. Images Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:2826130

Distel, B; Veenhuis, M; Tabak, H F

1987-01-01

90

ATP-Dependent Transport of Organic Anions in Secretory Vesicles of Saccharomyces cerevisiae  

Microsoft Academic Search

Secretory mutants (sec1, sec6) of Saccharomyces cerevisiae accumulate large pools of secretory vesicles at the restrictive temperature (37^circC) because of a block in the delivery of vesicles to the cell surface. We report that secretory vesicles isolated from sec mutants exhibit ATP-dependent uptake of two classes of organic anions that are substrates for the canalicular carriers of mammalian liver. Transport

Marie V. St-Pierre; Stephan Ruetz; Linda F. Epstein; Philippe Gros; Irwin M. Arias

1994-01-01

91

Response of Saccharomyces cerevisiae to the Stimulation of Lipopolysaccharide  

PubMed Central

Lipopolysaccharide, known as endotoxin, can stimulate potent host immune responses through the complex of Toll-like-receptor 4 and myeloid differentiation protein 2; but its influence on Saccharomyces cerevisiae, a model organism for studying eukaryotes, is not clear. In this study, we found that lipopolysaccharide-treated S. cerevisiae cells could be stained by methylene blue, but did not die. Transcriptional profiling of the lipopolysaccharide-treated S. cerevisiae cells showed that 5745 genes were modulated: 2491 genes up-regulated and 3254 genes down-regulated. Significantly regulated genes (460 up-regulated genes and 135 down-regulated genes) in lipopolysaccharide-treated S. cerevisiae cells were analyzed on Gene Ontology, and used to establish physical protein-protein interaction network and protein phosphorylation network. Based on these analyses, most of the regulated genes in lipopolysaccharide-treated S. cerevisiae cells were related to cell wall, membrane, peroxisome and mitochondrion. Further experiments demonstrated that lipopolysaccharide stimulation caused the exposure of phosphatidylserine and the increase of mitochondrial membrane potential in S. cerevisiae cells, but levels of intracellular reactive oxygen species and metacaspase activation were not increased. This study demonstrated that lipopolysaccharide stimulation causes significant changes in S. cerevisiae cells, and the results would contribute to understand the response of eukaryotic cells to lipopolysaccharide stimulation. PMID:25105496

Shen, Lulu; Li, Ye; Jiang, Linghuo; Wang, Xiaoyuan

2014-01-01

92

Biocatalytic production of dihydrocoumarin from coumarin by Saccharomyces cerevisiae.  

PubMed

Natural dihydrocoumarin, which is of great interest in the flavor industry, was biotechnologically produced from pure coumarin or tonka bean meal with Pseudomonas orientalis, Bacillus cereus, and various Saccharomyces cerevisiae strains. Coumarin was shown to be converted to melilotic acid, which yielded dihydrocoumarin upon distillation during purification. About 1.0 g/L product was obtained from 25 g/L tonka beans with S. cerevisiae within 147 h. This dihydrocoumarin thus fulfills all of the criteria of a natural raw material and can be used as a natural flavoring in accordance with U.S. and European Union regulations. PMID:16910713

Häser, Katrin; Wenk, Hans Henning; Schwab, Wilfried

2006-08-23

93

Predicting synthetic lethal genetic interactions in Saccharomyces cerevisiae using short polypeptide clusters  

E-print Network

PROCEEDINGS Open Access Predicting synthetic lethal genetic interactions in Saccharomyces cerevisiae using short polypeptide clusters Yuehua Zhang1, Bo Li1, Pradip K Srimani1, Xuewen Chen2, Feng Luo1* From IEEE International Conference... in Saccharomyces cerevisiae. Methods 2007, 41(2):206-221. 4. Schuldiner M, Collins SR, Weissman JS, Krogan NJ: Quantitative genetic analysis in Saccharomyces cerevisiae using epistatic miniarray profiles (E-MAPs) and its application to chromatin functions. Methods...

Zhang, Yuehua; Li, Bo; Srimani, Pradip K.; Chen, Xue-wen; Luo, Feng

2012-06-21

94

Saccharomyces cerevisiae STR3 and yeast cystathionine ?-lyase enzymes  

PubMed Central

Selected Saccharomyces cerevisiae strains are used for wine fermentation. Based on several criteria, winemakers often use a specific yeast to improve the flavor, mouth feel, decrease the alcohol content and desired phenolic content, just to name a few properties. Scientists at the AWRI previously illustrated the potential for increased flavor release from grape must via overexpression of the Escherichia coli Tryptophanase enzyme in wine yeast. To pursue a self-cloning approach for improving the aroma production, we recently characterized the S. cerevisiae cystathionine ?-lyase STR3, and investigated its flavor releasing capabilities. Here, we continue with a phylogenetic investigation of STR3 homologs from non-Saccharomyces yeasts to map the potential for using natural variation to engineer new strains. PMID:22572787

Holt, Sylvester; Cordente, Antonio G.; Curtin, Chris

2012-01-01

95

Saccharomyces cerevisiae: a sexy yeast with a prion problem.  

PubMed

Yeast prions are infectious proteins that spread exclusively by mating. The frequency of prions in the wild therefore largely reflects the rate of spread by mating counterbalanced by prion growth slowing effects in the host. We recently showed that the frequency of outcross mating is about 1% of mitotic doublings with 23-46% of total matings being outcrosses. These findings imply that even the mildest forms of the [PSI+], [URE3] and [PIN+] prions impart > 1% growth/survival detriment on their hosts. Our estimate of outcrossing suggests that Saccharomyces cerevisiae is far more sexual than previously thought and would therefore be more responsive to the adaptive effects of natural selection compared with a strictly asexual yeast. Further, given its large effective population size, a growth/survival detriment of > 1% for yeast prions should strongly select against prion-infected strains in wild populations of Saccharomyces cerevisiae. PMID:23764836

Kelly, Amy C; Wickner, Reed B

2013-01-01

96

The Reference Genome Sequence of Saccharomyces cerevisiae: Then and Now  

PubMed Central

The genome of the budding yeast Saccharomyces cerevisiae was the first completely sequenced from a eukaryote. It was released in 1996 as the work of a worldwide effort of hundreds of researchers. In the time since, the yeast genome has been intensively studied by geneticists, molecular biologists, and computational scientists all over the world. Maintenance and annotation of the genome sequence have long been provided by the Saccharomyces Genome Database, one of the original model organism databases. To deepen our understanding of the eukaryotic genome, the S. cerevisiae strain S288C reference genome sequence was updated recently in its first major update since 1996. The new version, called “S288C 2010,” was determined from a single yeast colony using modern sequencing technologies and serves as the anchor for further innovations in yeast genomic science. PMID:24374639

Engel, Stacia R.; Dietrich, Fred S.; Fisk, Dianna G.; Binkley, Gail; Balakrishnan, Rama; Costanzo, Maria C.; Dwight, Selina S.; Hitz, Benjamin C.; Karra, Kalpana; Nash, Robert S.; Weng, Shuai; Wong, Edith D.; Lloyd, Paul; Skrzypek, Marek S.; Miyasato, Stuart R.; Simison, Matt; Cherry, J. Michael

2014-01-01

97

Distribution and regulation of stochasticity and plasticity in Saccharomyces cerevisiae  

Stochasticity is an inherent feature of complex systems with nanoscale structure. In such systems information is represented by small collections of elements (e.g. a few electrons on a quantum dot), and small variations in the populations of these elements may lead to big uncertainties in the information. Unfortunately, little is known about how to work within this inherently noisy environment to design robust functionality into complex nanoscale systems. Here, we look to the biological cell as an intriguing model system where evolution has mediated the trade-offs between fluctuations and function, and in particular we look at the relationships and trade-offs between stochastic and deterministic responses in the gene expression of budding yeast (Saccharomyces cerevisiae). We find gene regulatory arrangements that control the stochastic and deterministic components of expression, and show that genes that have evolved to respond to stimuli (stress) in the most strongly deterministic way exhibit the most noise in the absence of the stimuli. We show that this relationship is consistent with a bursty 2-state model of gene expression, and demonstrate that this regulatory motif generates the most uncertainty in gene expression when there is the greatest uncertainty in the optimal level of gene expression.

Dar, R. D. [Oak Ridge National Laboratory (ORNL), TN (United States). Center for Nanophase Materials Science and Univ. of Tenneessee, Knoxville, TN (United States); Karig, D. K. [Oak Ridge National Laboratory (ORNL), TN (United States). Center for Nanophase Materials Science; Cooke, J. F. [Univ. of Tennessee, Knoxville, TN (United States); Cox, C. D. [Univ. of Tennessee, Knoxville, TN (United States); Simpson, M. L. [Oak Ridge National Laboratory (ORNL), TN (United States). Center for Nanophase Materials Science and Univ. of Tennessee, Knoxville, TN (United States)

2010-09-28

98

Genetic Analysis of Petite Mutants of SACCHAROMYCES CEREVISIAE : Transmissional Types  

PubMed Central

We have studied a number of petite [rho- ] mutants of Saccharomyces cerevisiae induced in a wild-type strain of mitochondrial genotype [ome- CHL R ERYS OLIS1,2,3 PARS] by Berenil and ethidium bromide, all of which have retained two mitochondrial genetic markers, [CHLR] and [ERYS], but have lost all other known markers. Though stable in their ability to retain these markers in their genome, these mutants vary widely among themselves in suppressiveness and in the extent to which the markers are transmitted on crossing to a common wild-type tested strain. In appropriate crosses all of the strains examined in this study demonstrate mitochondrial polarity, and thus have also retained the [ome-] locus in a functional form; however, five different transmissional types were obtained, several of them quite unusual, particularly among the strains originally induced by Berenil. One of the most interesting types is the one that appears to reverse the parental genotypes with [CHLR ERYS] predominating over [CHLS ERYR] in the diploid [rho+] progeny, rather than the reverse, which is characteristic of analogous crosses with [rho+] or other petites. Mutants in this class also exhibited low or no suppressiveness. Since all of the petites reported here are derived from the same wild-type parent, and so have the same nuclear background, we have interpreted the transmissional differences as being due to different intramolecular arrangements of largely common retained sequences. PMID:773749

Perlman, Philip S.

1976-01-01

99

Engineered Saccharomyces cerevisiae capable of simultaneous cellobiose and xylose fermentation  

PubMed Central

The use of plant biomass for biofuel production will require efficient utilization of the sugars in lignocellulose, primarily glucose and xylose. However, strains of Saccharomyces cerevisiae presently used in bioethanol production ferment glucose but not xylose. Yeasts engineered to ferment xylose do so slowly, and cannot utilize xylose until glucose is completely consumed. To overcome these bottlenecks, we engineered yeasts to coferment mixtures of xylose and cellobiose. In these yeast strains, hydrolysis of cellobiose takes place inside yeast cells through the action of an intracellular ?-glucosidase following import by a high-affinity cellodextrin transporter. Intracellular hydrolysis of cellobiose minimizes glucose repression of xylose fermentation allowing coconsumption of cellobiose and xylose. The resulting yeast strains, cofermented cellobiose and xylose simultaneously and exhibited improved ethanol yield when compared to fermentation with either cellobiose or xylose as sole carbon sources. We also observed improved yields and productivities from cofermentation experiments performed with simulated cellulosic hydrolyzates, suggesting this is a promising cofermentation strategy for cellulosic biofuel production. The successful integration of cellobiose and xylose fermentation pathways in yeast is a critical step towards enabling economic biofuel production. PMID:21187422

Ha, Suk-Jin; Galazka, Jonathan M.; Rin Kim, Soo; Choi, Jin-Ho; Yang, Xiaomin; Seo, Jin-Ho; Louise Glass, N.; Cate, Jamie H. D.; Jin, Yong-Su

2011-01-01

100

Distribution and regulation of stochasticity and plasticity in Saccharomyces cerevisiae  

NASA Astrophysics Data System (ADS)

Stochasticity is an inherent feature of complex systems with nanoscale structure. In such systems information is represented by small collections of elements (e.g., a few electrons on a quantum dot), and small variations in the populations of these elements may lead to big uncertainties in the information. Unfortunately, little is known about how to work within this inherently noisy environment to design robust functionality into complex nanoscale systems. Here, we look to the biological cell as an intriguing model system where evolution has mediated the trade-offs between fluctuations and function, and in particular we look at the relationships and trade-offs between stochastic and deterministic responses in the gene expression of budding yeast (Saccharomyces cerevisiae). We find gene regulatory arrangements that control the stochastic and deterministic components of expression, and show that genes that have evolved to respond to stimuli (stress) in the most strongly deterministic way exhibit the most noise in the absence of the stimuli. We show that this relationship is consistent with a bursty two-state model of gene expression, and demonstrate that this regulatory motif generates the most uncertainty in gene expression when there is the greatest uncertainty in the optimal level of gene expression.

Dar, R. D.; Karig, D. K.; Cooke, J. F.; Cox, C. D.; Simpson, M. L.

2010-09-01

101

Genotoxicity assessment of amaranth and allura red using Saccharomyces cerevisiae.  

PubMed

Amaranth (E123) and Allura red (E129), very important food azo dyes used in food, drug, paper, cosmetic and textile industries, were assessed for their genotoxic potential through comet assay in yeast cells. Comet assay was standardized by with different concentration of H(2)O(2). Concentrations of Amaranth and Allura red were maintained in sorbitol buffer starting from 9.76 to 5,000 ?g/mL and 1 × 10(4) cells were incubated at two different incubation temperatures 28 and 37°C. Amaranth (E123) and Allura red (E129) were found to exhibit their genotoxic effect directly in Saccharomyces cerevisiae. No significant genotoxic activity was observed for Amaranth and Allura red at 28°C but at 37°C direct relation of Amaranth concentration with comet tail was significant and no positive relation was seen with time exposure factor. At 37°C the minimum concentration of Amaranth and Allura red at which significant DNA damage observed through comet assay was 1,250 ?g/mL in 2nd h post exposure time. The results indicated that food colors should be carefully used in baking products as heavy concentration of food colors could affect the fermentation process of baking. PMID:23132362

Jabeen, Hafiza Sumara; ur Rahman, Sajjad; Mahmood, Shahid; Anwer, Sadaf

2013-01-01

102

Distribution and regulation of stochasticity and plasticity in Saccharomyces cerevisiae  

SciTech Connect

Stochasticity is an inherent feature of complex systems with nanoscale structure. In such systems information is represented by small collections of elements (e.g. a few electrons on a quantum dot), and small variations in the populations of these elements may lead to big uncertainties in the information. Unfortunately, little is known about how to work within this inherently noisy environment to design robust functionality into complex nanoscale systems. Here, we look to the biological cell as an intriguing model system where evolution has mediated the trade-offs between fluctuations and function, and in particular we look at the relationships and trade-offs between stochastic and deterministic responses in the gene expression of budding yeast (Saccharomyces cerevisiae). We find gene regulatory arrangements that control the stochastic and deterministic components of expression, and show that genes that have evolved to respond to stimuli (stress) in the most strongly deterministic way exhibit the most noise in the absence of the stimuli. We show that this relationship is consistent with a bursty 2-state model of gene expression, and demonstrate that this regulatory motif generates the most uncertainty in gene expression when there is the greatest uncertainty in the optimal level of gene expression.

Dar, Roy D. [University of Tennessee, Knoxville (UTK); Karig, David K [ORNL; Cooke, John F [ORNL; Cox, Chris D. [University of Tennessee, Knoxville (UTK); Simpson, Michael L [ORNL

2010-01-01

103

Expression of bacterial mercuric ion reductase in Saccharomyces cerevisiae.  

PubMed Central

The gene merA coding for bacterial mercuric ion reductase was cloned under the control of the yeast promoter for alcohol dehydrogenase I in the yeast-Escherichia coli shuttle plasmid pADH040-2 and transformed into Saccharomyces cerevisiae AH22. The resulting transformant harbored stable copies of the merA-containing hybrid plasmid, displayed a fivefold increase in the MIC of mercuric chloride, and synthesized mercuric ion reductase activity. Images PMID:1735719

Rensing, C; Kües, U; Stahl, U; Nies, D H; Friedrich, B

1992-01-01

104

Saccharomyces cerevisiae Yta7 Regulates Histone Gene Expression  

Microsoft Academic Search

The Saccharomyces cerevisiae Yta7 protein is a component of a nucleosome bound protein complex that maintains distinct transcriptional zones of chromatin. We previously found that one protein copurifying with Yta7 is the yFACT member Spt16. Epistasis analyses revealed a link between Yta7, Spt16, and other previously identified members of the histone regulatory pathway. In concurrence, Yta7 was found to reg-

Angeline Gradolatto; Richard S. Rogers; Heather Lavender; Sean D. Taverna; C. David Allis; John D. Aitchison; Alan J. Tackett

2008-01-01

105

Calorie restriction extends Saccharomyces cerevisiae lifespan by increasing respiration  

Microsoft Academic Search

Calorie restriction (CR) extends lifespan in a wide spectrum of organisms and is the only regimen known to lengthen the lifespan of mammals. We established a model of CR in budding yeast Saccharomyces cerevisiae. In this system, lifespan can be extended by limiting glucose or by reducing the activity of the glucose-sensing cyclic-AMP-dependent kinase (PKA). Lifespan extension in a mutant

Su-Ju Lin; Matt Kaeberlein; Alex A. Andalis; Lori A. Sturtz; Pierre-Antoine Defossez; Valeria C. Culotta; Gerald R. Fink; Leonard Guarente

2002-01-01

106

A Mutant of Saccharomyces cerevisiae Defective for Nuclear Fusion  

Microsoft Academic Search

A mutant unable to fuse nuclei during mating has been isolated from standard wild-type Saccharomyces cerevisiae. Tetrad analysis of the mutation responsible for this defect (kar1-1) shows that it segregates as a single Mendelian factor. The defect in kar1-1 appears to be nuclear limited. Cytological and genetic evidence shows that in this mutant the events associated with zygote formation are

Jaime Conde; Gerald R. Fink

1976-01-01

107

Small molecule activators of sirtuins extend Saccharomyces cerevisiae lifespan  

Microsoft Academic Search

In diverse organisms, calorie restriction slows the pace of ageing and increases maximum lifespan. In the budding yeast Saccharomyces cerevisiae, calorie restriction extends lifespan by increasing the activity of Sir2 (ref. 1), a member of the conserved sirtuin family of NAD+-dependent protein deacetylases. Included in this family are SIR-2.1, a Caenorhabditis elegans enzyme that regulates lifespan, and SIRT1, a human

Konrad T. Howitz; Kevin J. Bitterman; Haim Y. Cohen; Dudley W. Lamming; Siva Lavu; Jason G. Wood; Robert E. Zipkin; Phuong Chung; Anne Kisielewski; Li-Li Zhang; Brandy Scherer; David A. Sinclair

2003-01-01

108

Global landscape of protein complexes in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

Identification of protein–protein interactions often provides insight into protein function, and many cellular processes are performed by stable protein complexes. We used tandem affinity purification to process 4,562 different tagged proteins of the yeast Saccharomyces cerevisiae. Each preparation was analysed by both matrix-assisted laser desorption\\/ionization–time of flight mass spectrometry and liquid chromatography tandem mass spectrometry to increase coverage and accuracy.

Nevan J. Krogan; Gerard Cagney; Haiyuan Yu; Gouqing Zhong; Xinghua Guo; Alexandr Ignatchenko; Joyce Li; Shuye Pu; Nira Datta; Aaron P. Tikuisis; Thanuja Punna; José M. Peregrín-Alvarez; Michael Shales; Xin Zhang; Michael Davey; Mark D. Robinson; Alberto Paccanaro; James E. Bray; Anthony Sheung; Bryan Beattie; Dawn P. Richards; Veronica Canadien; Atanas Lalev; Frank Mena; Peter Wong; Andrei Starostine; Myra M. Canete; James Vlasblom; Samuel Wu; Chris Orsi; Sean R. Collins; Shamanta Chandran; Robin Haw; Jennifer J. Rilstone; Kiran Gandi; Natalie J. Thompson; Gabe Musso; Peter St Onge; Shaun Ghanny; Mandy H. Y. Lam; Gareth Butland; Amin M. Altaf-Ul; Shigehiko Kanaya; Ali Shilatifard; Erin O'Shea; Jonathan S. Weissman; C. James Ingles; Timothy R. Hughes; John Parkinson; Mark Gerstein; Shoshana J. Wodak; Andrew Emili; Jack F. Greenblatt

2006-01-01

109

Effect of Polygodial on the Mitochondrial ATPase of Saccharomyces cerevisiae  

Microsoft Academic Search

The fungicidal mechanism of a naturally occurring sesquiterpene dialdehyde, polygodial, was investigated in Saccharomyces cerevisiae. In an acidification assay, polygodial completely suppressed the glucose-induced de- crease in external pH at 3.13 mg\\/ml, the same as the fungicidal concentration. Acidification occurs primarily through the proton-pumping action of the plasma membrane ATPase, Pma1p. Surprisingly, this ATPase was not directly inhibited by polygodial.

CHRISTOPHER S. LUNDE; ISAO KUBO

2000-01-01

110

Statistics-based model for prediction of chemical biosynthesis yield from Saccharomyces cerevisiae  

E-print Network

Background: The robustness of Saccharomyces cerevisiae in facilitating industrial-scale production of ethanol extends its utilization as a platform to synthesize other metabolites. Metabolic engineering strategies, typically ...

Xiao, Yi

111

Truncation of the caspase-related subunit (Gpi8p) of Saccharomyces cerevisiae GPI transamidase: Dimerization revealed  

E-print Network

, Saccharomyces cerevisiae; SPPS, solid-Author's personal copy Truncation of the caspase-related subunit (Gpi8p) of Saccharomyces cerevisiae GPI transamidase: Dimerization revealed Jennifer L. Meitzler a , Jeffrey J. Gray b,c , Tamara L

Gray, Jeffrey J.

112

In vitro study of the dose effect of Saccharomyces cerevisiae on rumen digestion of a mixed diet  

E-print Network

In vitro study of the dose effect of Saccharomyces cerevisiae on rumen digestion of a mixed diet JP of Saccharomyces cerevisiae (I-1077)* (SC) were tested in Rusitec to study their effects on rumen digestive

Paris-Sud XI, Université de

113

Saccharomyces cerevisiae and non-Saccharomyces yeasts in grape varieties of the São Francisco Valley.  

PubMed

The aims of this work was to characterise indigenous Saccharomyces cerevisiae strains in the naturally fermented juice of grape varieties Cabernet Sauvignon, Grenache, Tempranillo, Sauvignon Blanc and Verdejo used in the São Francisco River Valley, northeastern Brazil. In this study, 155 S. cerevisiae and 60 non-Saccharomyces yeasts were isolated and identified using physiological tests and sequencing of the D1/D2 domains of the large subunit of the rRNA gene. Among the non-Saccharomyces species, Rhodotorula mucilaginosa was the most common species, followed by Pichia kudriavzevii, Candida parapsilosis, Meyerozyma guilliermondii, Wickerhamomyces anomalus, Kloeckera apis, P. manshurica, C. orthopsilosis and C. zemplinina. The population counts of these yeasts ranged among 1.0 to 19 × 10(5) cfu/mL. A total of 155 isolates of S. cerevisiae were compared by mitochondrial DNA restriction analysis, and five molecular mitochondrial DNA restriction profiles were detected. Indigenous strains of S. cerevisiae isolated from grapes of the São Francisco Valley can be further tested as potential starters for wine production. PMID:25242923

de Ponzzes-Gomes, Camila M P B S; de Mélo, Dângelly L F M; Santana, Caroline A; Pereira, Giuliano E; Mendonça, Michelle O C; Gomes, Fátima C O; Oliveira, Evelyn S; Barbosa, Antonio M; Trindade, Rita C; Rosa, Carlos A

2014-01-01

114

Saccharomyces cerevisiae as a Model Organism: A Comparative Study  

E-print Network

Background: Model organisms are used for research because they provide a framework on which to develop and optimize methods that facilitate and standardize analysis. Such organisms should be representative of the living beings for which they are to serve as proxy. However, in practice, a model organism is often selected ad hoc, and without considering its representativeness, because a systematic and rational method to include this consideration in the selection process is still lacking. Methodology/Principal Findings: In this work we propose such a method and apply it in a pilot study of strengths and limitations of Saccharomyces cerevisiae as a model organism. The method relies on the functional classification of proteins into different biological pathways and processes and on full proteome comparisons between the putative model organism and other organisms for which we would like to extrapolate results. Here we compare S. cerevisiae to 704 other organisms from various phyla. For each organism, our results identify the pathways and processes for which S. cerevisiae is predicted to be a good model to extrapolate from. We find that animals in general and Homo sapiens in particular are some of the nonfungal organisms for which S. cerevisiae is likely to be a good model in which to study a significant fraction of common biological processes. We validate our approach by correctly predicting which organisms are phenotypically more distant from S. cerevisiae with respect to several different biological processes.

Hiren Karathia; Ester Vilaprinyo; Albert Sorribas; Rui Alves

115

Discontinuity induced bifurcations in a model of Saccharomyces cerevisiae D.J.W. Simpson a,*, D.S. Kompala b  

E-print Network

Discontinuity induced bifurcations in a model of Saccharomyces cerevisiae D.J.W. Simpson a,*, D of Saccharomyces cerevisiae in batch and continuous cultures, J. Biotechnol. 71 (1999) 105­131]. Stable for instance [6­8]. Saccharomyces cerevisiae has three metabolic pathways for glu- cose: fermentation, ethanol

Meiss, James

116

Secreted 3-Isopropylmalate Methyl Ester Signals Invasive Growth during Amino Acid Starvation in Saccharomyces cereVisiae  

E-print Network

in Saccharomyces cereVisiae Darren S. Dumlao, Nicholas Hertz, and Steven Clarke* Department of Chemistry). Yeast such as Saccharomyces cereVisiae undergo a morphological switch from unicellular growth characterizing the Saccharomyces cereVisiae YER175C gene product Tmt1, which encodes a methyltransferase involved

Clarke, Steven

117

Function Prediction for Hypothetical Proteins in Yeast Saccharomyces cerevisiae Using Multiple Sources of High-Throughput Data  

E-print Network

1 Function Prediction for Hypothetical Proteins in Yeast Saccharomyces cerevisiae Using Multiple have applied our method to yeast Saccharomyces cerevisiae and predicted functions for 1548 out of 2472, yeast, high- throughput data, Saccharomyces cerevisiae. #12;3 1.INTRODUCTION Determination of protein

118

Crystal structure of the heterotrimer core of Saccharomyces cerevisiae AMPK homologue SNF1  

E-print Network

LETTERS Crystal structure of the heterotrimer core of Saccharomyces cerevisiae AMPK homologue SNF1, obesity and other diseases1­5 . The AMPK homologue in Saccharomyces cerevisiae, known as SNF1, is essential for responses to glucose starvation as well as for other cellular processes, although SNF1 seems

Tong, Liang

119

Whole-genome expression analysis of snf swi mutants of Saccharomyces cerevisiae  

E-print Network

Whole-genome expression analysis of snf swi mutants of Saccharomyces cerevisiae Priya Sudarsanam (received for review September 22, 1999) The Saccharomyces cerevisiae Snf Swi complex has been previ- ously mutants deleted for a gene encoding one conserved (Snf2) or one unconserved (Swi1) Snf Swi component

Ghosh, Joydeep

120

Potassium is an Activator of Homoisocitrate Dehydrogenase from Saccharomyces cerevisiae†  

PubMed Central

Potassium is an activator of the reaction catalyzed by homoisocitrate (HIc) dehydrogenase (HIcDH) from Saccharomyces cerevisiae with either the natural substrate, homoisocitrate, or the slow substrate isocitrate. On the basis of initial velocity studies, the selectivity of the activator site for monovalent ions was determined. Potassium is the best activator, and NH4+ and Rb+ are also activators of the reaction, while Cs+, Li+, and Na+ are not. Chloride inhibits the reaction, while acetate is much less effective. Substitution of potassium acetate for KCl changes the kinetic mechanism of HIcDH from a steady state random to a fully ordered mechanism with the binding of MgHIc followed by K+ and NAD. The change in mechanism likely reflects an apparent increase in the affinity of enzyme for MgHIc as a result of elimination of the inhibitory effect of Cl?. The V/KNAD pH-rate profile in the absence of K+ exhibits a >10-fold decrease in the affinity of enzyme for NAD upon deprotonation of an enzyme side chain with a pKa of about 5.5–6. On the other hand, the affinity for NAD is relatively constant at high pH in the presence of 200 mM KCl. Since the affinity of the dinucleotide decreases as the enzyme group is protonated and the effect is overcome by a monovalent cation, the enzyme residue may be likely a neutral acid, aspartate or glutamate. Data suggest that K+ replaces the proton, and likely binds to the enzyme residue, the pyrophosphoryl moiety of NAD, or both. Viscosity and solvent deuterium isotope effects studies suggest the isomerization of E-MgHIc binary complex limits the rate in the absence of K+. PMID:18785753

Lin, Ying; West, Ann H.; Cook, Paul F.

2009-01-01

121

Fenpropimorph affects uptake of uracil and cytosine in Saccharomyces cerevisiae.  

PubMed Central

Fenpropimorph was shown to inhibit the accumulation of the pyrimidine bases uracil and cytosine from the growth media in Saccharomyces cerevisiae. Uracil prototrophs of S. cerevisiae were more resistant to the growth-inhibitory effects of fenpropimorph than were uracil auxotrophs. High concentrations of uracil rescued fenpropimorph-treated uracil auxotrophs, and cytosine, which is accumulated by a separate mechanism, could also support growth of treated uracil auxotrophs. Fenpropimorph caused a significant decrease in the uptake of radiolabeled uracil, which was not due to accumulation of ergosta-8,14-dienol (ignosterol) in the treated cultures. Radiolabeled cytosine uptake was unaffected by drug treatment in a wild-type strain but was inhibited in a sterol mutant, in which ergosterol was absent from the cell. The role of fenpropimorph in causing membrane dysfunction through a mechanism other than altered sterol metabolism is discussed. PMID:8067730

Crowley, J H; Lorenz, R T; Parks, L W

1994-01-01

122

Interorganelle signaling is a determinant of longevity in Saccharomyces cerevisiae.  

PubMed Central

Replicative capacity, which is the number of times an individual cell divides, is the measure of longevity in the yeast Saccharomyces cerevisiae. In this study, a process that involves signaling from the mitochondrion to the nucleus, called retrograde regulation, is shown to determine yeast longevity, and its induction resulted in postponed senescence. Activation of retrograde regulation, by genetic and environmental means, correlated with increased replicative capacity in four different S. cerevisiae strains. Deletion of a gene required for the retrograde response, RTG2, eliminated the increased replicative capacity. RAS2, a gene previously shown to influence longevity in yeast, interacts with retrograde regulation in setting yeast longevity. The molecular mechanism of aging elucidated here parallels the results of genetic studies of aging in nematodes and fruit flies, as well as the caloric restriction paradigm in mammals, and it underscores the importance of metabolic regulation in aging, suggesting a general applicability. PMID:10224252

Kirchman, P A; Kim, S; Lai, C Y; Jazwinski, S M

1999-01-01

123

Advanced biofuel production by the yeast Saccharomyces cerevisiae.  

PubMed

Replacement of conventional transportation fuels with biofuels will require production of compounds that can cover the complete fuel spectrum, ranging from gasoline to kerosene. Advanced biofuels are expected to play an important role in replacing fossil fuels because they have improved properties compared with ethanol and some of these may have the energy density required for use in heavy duty vehicles, ships, and aviation. Moreover, advanced biofuels can be used as drop-in fuels in existing internal combustion engines. The yeast cell factory Saccharomyces cerevisiae can be turned into a producer of higher alcohols (1-butanol and isobutanol), sesquiterpenes (farnesene and bisabolene), and fatty acid ethyl esters (biodiesel), and here we discusses progress in metabolic engineering of S. cerevisiae for production of these advanced biofuels. PMID:23628723

Buijs, Nicolaas A; Siewers, Verena; Nielsen, Jens

2013-06-01

124

Some characteristics of tetraphenylphosphonium uptake into Saccharomyces cerevisiae.  

PubMed

The characteristics of the uptake of the lipophilic cation tetraphenylphosphonium (TPP+) into Saccharomyces cerevisiae have been investigated in order to establish whether this compound can be used to monitor the membrane potential of his organism. Unlike dibenzyldimethylammonium, TPP+ is not translocated via the thiamine transport system, nor via another inducible translocation mechanism. On changing the experimental conditions the equilibrium potential of TPP+ varies according to expected changes of the membrane potential. TPP+ accumulation is higher in metabolizing cells than in non-metabolizing cells. In addition, decreasing the medium pH, addition of the proton conductor 2,4-dinitrophenol and addition of K+ all cause an apparent depolarization, whereas Ca2+ apparently hyperpolarizes the cell membrane. It is concluded that TPP+, if applied at low concentrations, can be used to measure the membrane potential of S. cerevisiae. PMID:7039677

Boxman, A W; Barts, P W; Borst-Pauwels, G W

1982-03-23

125

Biosorption of heavy metals by Saccharomyces cerevisiae: a review.  

PubMed

Heavy metal pollution has become one of the most serious environmental problems today. Biosorption, using biomaterials such as bacteria, fungi, yeast and algae, is regarded as a cost-effective biotechnology for the treatment of high volume and low concentration complex wastewaters containing heavy metal(s) in the order of 1 to 100 mg/L. Among the promising biosorbents for heavy metal removal which have been researched during the past decades, Saccharomyces cerevisiae has received increasing attention due to the unique nature in spite of its mediocre capacity for metal uptake compared with other fungi. S. cerevisiae is widely used in food and beverage production, is easily cultivated using cheap media, is also a by-product in large quantity as a waste of the fermentation industry, and is easily manipulated at molecular level. The state of the art in the field of biosorption of heavy metals by S. cerevisiae not only in China, but also worldwide, is reviewed in this paper, based on a substantial number of relevant references published recently on the background of biosorption achievements and development. Characteristics of S. cerevisiae in heavy metal biosorption are extensively discussed. The yeast can be studied in various forms for different purposes. Metal-binding capacity for various heavy metals by S. cerevisiae under different conditions is compared. Lead and uranium, for instances, could be removed from dilute solutions more effectively in comparison with other metals. The yeast biosorption largely depends on parameters such as pH, the ratio of the initial metal ion and initial biomass concentration, culture conditions, presence of various ligands and competitive metal ions in solution and to a limited extent on temperature. An assessment of the isotherm equilibrium model, as well as kinetics was performed. The mechanisms of biosorption are understood only to a limited extent. Elucidation of the mechanism of metal uptake is a real challenge in the field of biosorption. Various mechanism assumptions of metal uptake by S. cerevisiae are summarized. PMID:16737792

Wang, Jianlong; Chen, Can

2006-01-01

126

Transfer RNA splicing in Saccharomyces cerevisiae: defining the substrates.  

PubMed Central

The primary sequences of all the tRNA precursors which contain intervening sequences and which accumulate in the Saccharomyces cerevisiae rnal mutant are presented. A combination of DNA and RNA sequence analysis has led to elucidation of the primary sequence of four hitherto uncharacterized precursors. The location of the intervening sequence has in all cases been unambiguously determined by analysis of the intermediates in the splicing reaction. Secondary structures based upon the tRNA cloverleaf are shown for all the tRNA precursors and discussed with respect to common recognition by the yeast splicing endonuclease. Images PMID:6096826

Ogden, R C; Lee, M C; Knapp, G

1984-01-01

127

Discontinuity Induced Bifurcations in a Model of Saccharomyces cerevisiae  

E-print Network

We perform a bifurcation analysis of the mathematical model of Jones and Kompala [K.D. Jones and D.S. Kompala, Cybernetic model of the growth dynamics of Saccharomyces cerevisiae in batch and continuous cultures, J. Biotech., 71:105-131, 1999]. Stable oscillations arise via Andronov-Hopf bifurcations and exist for intermediate values of the dilution rate as has been noted from experiments previously. A variety of discontinuity induced bifurcations arise from a lack of global differentiability. We identify and classify discontinuous bifurcations including several codimension-two scenarios. Bifurcation diagrams are explained by a general unfolding of these singularities.

D. J. W. Simpson; D. S. Kompala; J. D. Meiss

2008-07-01

128

Mutagenicity and recombinogenicity of daunomycin in Saccharomyces cerevisiae.  

PubMed

The antineoplastic antibiotic daunomycin was tested for mutagenic and recombinogenic effects in haploid and diploid strains of Saccharomyces cerevisiae. This antibiotic failed to induce mutations to lysine and histidine independence in the haploid strain, XV 185-14C, carrying the auxotrophic markers lysl-1 and hisl-7. On the contrary, daunomycin did induce aberrant colonies, including reciprocal products of mitotic crossing over in the diploid strain D7. The results suggest that while daunomycin may be recombinogenic, its mutagenic effects, if any, are either highly specific or negligible. The significance of these results in evaluating the mutagenic/carcinogenic potential of antitumor agents is discussed. PMID:365321

Hannan, M A; Nasim, A

1978-12-01

129

Genetic effects of 5-azacytidine in Saccharomyces cerevisiae.  

PubMed

The base analog 5-azacytidine induced a variety of genetic and epigenetic effects in different organisms. It was tested in two diploid strains of the yeast Saccharomyces cerevisiae to study the induction of point mutation, mitotic reciprocal crossing-over, mitotic gene conversion (strain D7) and mitotic aneuploidy (strain D61.M). It was used on cells growing in its presence for 4-5 generations. There was a strong induction of both types of mitotic recombination and point mutation. However, there was no induction of mitotic chromosomal malsegregation under the same conditions. PMID:6197648

Zimmermann, F K; Scheel, I

1984-01-01

130

Strain engineering of Saccharomyces cerevisiae for enhanced xylose metabolism.  

PubMed

Efficient and rapid fermentation of all sugars present in cellulosic hydrolysates is essential for economic conversion of renewable biomass into fuels and chemicals. Xylose is one of the most abundant sugars in cellulosic biomass but it cannot be utilized by wild type Saccharomyces cerevisiae, which has been used for industrial ethanol production. Therefore, numerous technologies for strain development have been employed to engineer S. cerevisiae capable of fermenting xylose rapidly and efficiently. These include i) optimization of xylose-assimilating pathways, ii) perturbation of gene targets for reconfiguring yeast metabolism, and iii) simultaneous co-fermentation of xylose and cellobiose. In addition, the genetic and physiological background of host strains is an important determinant to construct efficient and rapid xylose-fermenting S. cerevisiae. Vibrant and persistent researches in this field for the last two decades not only led to the development of engineered S. cerevisiae strains ready for industrial fermentation of cellulosic hydrolysates, but also deepened our understanding of operational principles underlying yeast metabolism. PMID:23524005

Kim, Soo Rin; Park, Yong-Cheol; Jin, Yong-Su; Seo, Jin-Ho

2013-11-01

131

Heterologous expression of a Clostridium minicellulosome in Saccharomyces cerevisiae.  

PubMed

The yeast Saccharomyces cerevisiae was genetically modified to assemble a minicellulosome on its cell surface by heterologous expression of a chimeric scaffoldin protein from Clostridium cellulolyticum under the regulation of the phosphoglycerate kinase 1 (PGK1) promoter and terminator regulatory elements, together with the beta-xylanase 2 secretion signal of Trichoderma reesei and cell wall protein 2 (Cwp2) of S. cerevisiae. Fluorescent microscopy and Far Western blot analysis confirmed that the Scaf3p is targeted to the yeast cell surface and that the Clostridium thermocellum cohesin domain is functional in yeast. Similarly, functionality of the C. thermocellum dockerin domain in yeast is shown by binding to the Scaf3 protein in Far Western blot analysis. Phenotypic evidence for cohesin-dockerin interaction was also established with the detection of a twofold increase in tethered endoglucanase enzyme activity in S. cerevisiae cells expressing the Scaf3 protein compared with the parent strain. This study highlights the feasibility to future design of enhanced cellulolytic strains of S. cerevisiae through emulation of the cellulosome concept. Potentially, Scaf3p-armed yeast could also be developed into an alternative cell surface display strategy with various tailor-made applications. PMID:19744245

Lilly, Mariska; Fierobe, Henri-Pierre; van Zyl, Willem H; Volschenk, Heinrich

2009-12-01

132

Saccharomyces cerevisiae: Population Divergence and Resistance to Oxidative Stress in Clinical, Domesticated and Wild Isolates  

PubMed Central

Background Saccharomyces cerevisiae has been associated with human life for millennia in the brewery and bakery. Recently it has been recognized as an emerging opportunistic pathogen. To study the evolutionary history of S. cerevisiae, the origin of clinical isolates and the importance of a virulence-associated trait, population genetics and phenotypic assays have been applied to an ecologically diverse set of 103 strains isolated from clinics, breweries, vineyards, fruits, soil, commercial supplements and insect guts. Methodology/Principal Findings DNA sequence data from five nuclear DNA loci were analyzed for population structure and haplotype distribution. Additionally, all strains were tested for survival of oxidative stress, a trait associated with microbial pathogenicity. DNA sequence analyses identified three genetic subgroups within the recombining S. cerevisiae strains that are associated with ecology, geography and virulence. Shared alleles suggest that the clinical isolates contain genetic contribution from the fruit isolates. Clinical and fruit isolates exhibit high levels of recombination, unlike the genetically homogenous soil isolates in which no recombination was detected. However, clinical and soil isolates were more resistant to oxidative stress than any other population, suggesting a correlation between survival in oxidative stress and yeast pathogenicity. Conclusions/Significance Population genetic analyses of S. cerevisiae delineated three distinct groups, comprising primarily the (i) human-associated brewery and vineyard strains, (ii) clinical and fruit isolates (iii) and wild soil isolates from eastern U.S. The interactions between S. cerevisiae and humans potentiate yeast evolution and the development of genetically, ecologically and geographically divergent groups. PMID:19390633

Diezmann, Stephanie; Dietrich, Fred S.

2009-01-01

133

Saccharomyces boulardii  

MedlinePLUS

... is now believed to be a strain of Saccharomyces cerevisiae (baker's yeast). Saccharomyces boulardii is used as medicine. ... Hansen CBS 5926), Probiotic, Probiotique, Saccharomyces, Saccharomyces boulardii, Saccharomyces Cerevisiae, S. Boulardii.

134

Expression of Pneumocystis jirovecii major surface glycoprotein in Saccharomyces cerevisiae.  

PubMed

The major surface glycoprotein (Msg), which is the most abundant protein expressed on the cell surface of Pneumocystis organisms, plays an important role in the attachment of this organism to epithelial cells and macrophages. In the present study, we expressed Pneumocystis jirovecii Msg in Saccharomyces cerevisiae, a phylogenetically related organism. Full-length P. jirovecii Msg was expressed with a DNA construct that used codons optimized for expression in yeast. Unlike in Pneumocystis organisms, recombinant Msg localized to the plasma membrane of yeast rather than to the cell wall. Msg expression was targeted to the yeast cell wall by replacing its signal peptide, serine-threonine-rich region, and glycophosphatidylinositol anchor signal region with the signal peptide of cell wall protein ?-agglutinin of S. cerevisiae, the serine-threonine-rich region of epithelial adhesin (Epa1) of Candida glabrata, and the carboxyl region of the cell wall protein (Cwp2) of S. cerevisiae, respectively. Immunofluorescence analysis and treatment with ?-1,3 glucanase demonstrated that the expressed Msg fusion protein localized to the yeast cell wall. Surface expression of Msg protein resulted in increased adherence of yeast to A549 alveolar epithelial cells. Heterologous expression of Msg in yeast will facilitate studies of the biologic properties of Pneumocystis Msg. PMID:23532098

Kutty, Geetha; England, Katherine J; Kovacs, Joseph A

2013-07-01

135

Biogeographical characterization of Saccharomyces cerevisiae wine yeast by molecular methods.  

PubMed

Biogeography is the descriptive and explanatory study of spatial patterns and processes involved in the distribution of biodiversity. Without biogeography, it would be difficult to study the diversity of microorganisms because there would be no way to visualize patterns in variation. Saccharomyces cerevisiae, "the wine yeast," is the most important species involved in alcoholic fermentation, and in vineyard ecosystems, it follows the principle of "everything is everywhere." Agricultural practices such as farming (organic versus conventional) and floor management systems have selected different populations within this species that are phylogenetically distinct. In fact, recent ecological and geographic studies highlighted that unique strains are associated with particular grape varieties in specific geographical locations. These studies also highlighted that significant diversity and regional character, or 'terroir,' have been introduced into the winemaking process via this association. This diversity of wild strains preserves typicity, the high quality, and the unique flavor of wines. Recently, different molecular methods were developed to study population dynamics of S. cerevisiae strains in both vineyards and wineries. In this review, we will provide an update on the current molecular methods used to reveal the geographical distribution of S. cerevisiae wine yeast. PMID:23805132

Tofalo, Rosanna; Perpetuini, Giorgia; Schirone, Maria; Fasoli, Giuseppe; Aguzzi, Irene; Corsetti, Aldo; Suzzi, Giovanna

2013-01-01

136

Role of social wasps in Saccharomyces cerevisiae ecology and evolution.  

PubMed

Saccharomyces cerevisiae is one of the most important model organisms and has been a valuable asset to human civilization. However, despite its extensive use in the last 9,000 y, the existence of a seasonal cycle outside human-made environments has not yet been described. We demonstrate the role of social wasps as vector and natural reservoir of S. cerevisiae during all seasons. We provide experimental evidence that queens of social wasps overwintering as adults (Vespa crabro and Polistes spp.) can harbor yeast cells from autumn to spring and transmit them to their progeny. This result is mirrored by field surveys of the genetic variability of natural strains of yeast. Microsatellites and sequences of a selected set of loci able to recapitulate the yeast strain's evolutionary history were used to compare 17 environmental wasp isolates with a collection of strains from grapes from the same region and more than 230 strains representing worldwide yeast variation. The wasp isolates fall into subclusters representing the overall ecological and industrial yeast diversity of their geographic origin. Our findings indicate that wasps are a key environmental niche for the evolution of natural S. cerevisiae populations, the dispersion of yeast cells in the environment, and the maintenance of their diversity. The close relatedness of several wasp isolates with grape and wine isolates reflects the crucial role of human activities on yeast population structure, through clonal expansion and selection of specific strains during the biotransformation of fermented foods, followed by dispersal mediated by insects and other animals. PMID:22847440

Stefanini, Irene; Dapporto, Leonardo; Legras, Jean-Luc; Calabretta, Antonio; Di Paola, Monica; De Filippo, Carlotta; Viola, Roberto; Capretti, Paolo; Polsinelli, Mario; Turillazzi, Stefano; Cavalieri, Duccio

2012-08-14

137

Ciclohexadespipeptide beauvericin degradation by different strains of Saccharomyces cerevisiae.  

PubMed

The interaction between the mycotoxin beauvericin (BEA) and 9 yeast strains of Saccharomyces cerevisiae named LO9, YE-2, YE5, YE-6, YE-4, A34, A17, A42 and A08 was studied. The biological degradations were carried out under aerobic conditions in the liquid medium of Potato Dextrose Broth (PDB) at 25°C for 48 h and in a food/feed system composed of corn flour at 37°C for 3 days, respectively. BEA present in fermented medium and corn flour was determined using liquid chromatography coupled to the mass spectrometry detector in tandem (LC-MS/MS) and the BEA degradation products produced during the fermentations were determined using the technique of the liquid chromatography coupled to a linear ion trap (LIT). Results showed that the S. cerevisiae strains reduced meanly the concentration of the BEA present in PDB by 86.2% and in a food system by 71.1%. All the S. cerevisiae strains used in this study showed a significant BEA reduction during the fermentation process employed. PMID:23791659

Meca, G; Zhou, T; Li, X Z; Ritieni, A; Mañes, J

2013-09-01

138

Increasing NADH oxidation reduces overflow metabolism in Saccharomyces cerevisiae  

PubMed Central

Respiratory metabolism plays an important role in energy production in the form of ATP in all aerobically growing cells. However, a limitation in respiratory capacity results in overflow metabolism, leading to the formation of byproducts, a phenomenon known as “overflow metabolism” or “the Crabtree effect.” The yeast Saccharomyces cerevisiae has served as an important model organism for studying the Crabtree effect. When subjected to increasing glycolytic fluxes under aerobic conditions, there is a threshold value of the glucose uptake rate at which the metabolism shifts from purely respiratory to mixed respiratory and fermentative. It is well known that glucose repression of respiratory pathways occurs at high glycolytic fluxes, resulting in a decrease in respiratory capacity. Despite many years of detailed studies on this subject, it is not known whether the onset of the Crabtree effect is due to limited respiratory capacity or is caused by glucose-mediated repression of respiration. When respiration in S. cerevisiae was increased by introducing a heterologous alternative oxidase, we observed reduced aerobic ethanol formation. In contrast, increasing nonrespiratory NADH oxidation by overexpression of a water-forming NADH oxidase reduced aerobic glycerol formation. The metabolic response to elevated alternative oxidase occurred predominantly in the mitochondria, whereas NADH oxidase affected genes that catalyze cytosolic reactions. Moreover, NADH oxidase restored the deficiency of cytosolic NADH dehydrogenases in S. cerevisiae. These results indicate that NADH oxidase localizes in the cytosol, whereas alternative oxidase is directed to the mitochondria. PMID:17287356

Vemuri, G. N.; Eiteman, M. A.; McEwen, J. E.; Olsson, L.; Nielsen, J.

2007-01-01

139

The postmitotic Saccharomyces cerevisiae after spaceflight showed higher viability  

NASA Astrophysics Data System (ADS)

The budding yeast Saccharomyces cerevisiae has been proposed as an ideal model organism for clarifying the biological effects caused by spaceflight conditions. The postmitotic S. cerevisiae cells onboard Practice eight recoverable satellite were subjected to spaceflight for 15 days. After recovery, the viability, the glycogen content, the activities of carbohydrate metabolism enzymes, the DNA content and the lipid peroxidation level in yeast cells were analyzed. The viability of the postmitotic yeast cells after spaceflight showed a three-fold increase as compared with that of the ground control cells. Compared to the ground control cells, the lipid peroxidation level in the spaceflight yeast cells markedly decreased. The spaceflight yeast cells also showed an increase in G2/M cell population and a decrease in Sub-G1 cell population. The glycogen content and the activities of hexokinase and succinate dehydrogenase significantly decreased in the yeast cells after spaceflight. In contrast, the activity of malate dehydrogenase showed an obvious increase after spaceflight. These results suggested that microgravity or spaceflight could promote the survival of postmitotic S. cerevisiae cells through regulating carbohydrate metabolism, ROS level and cell cycle progression.

Yi, Zong-Chun; Li, Xiao-Fei; Wang, Yan; Wang, Jie; Sun, Yan; Zhuang, Feng-Yuan

2011-06-01

140

Ethanol production by Saccharomyces cerevisiae in biofilm reactors.  

PubMed

Biofilms are natural forms of cell immobilization in which microorganisms attach to solid supports. At ISU, we have developed plastic composite-supports (PCS) (agricultural material (soybean hulls or oat hulls), complex nutrients, and polypropylene) which stimulate biofilm formation and which supply nutrients to the attached microorganisms. Various PCS blends were initially evaluated in repeated-batch culture-tube fermentation with Saccharomyces cerevisiae (ATCC 24859) in low organic nitrogen medium. The selected PCS (40% soybean hull, 5% soybean flour, 5% yeast extract-salt and 50% polypropylene) was then used in continuous and repeated-batch fermentation in various media containing lowered nitrogen content with selected PCS. During continuous fermentation, S. cerevisiae demonstrated two to 10 times higher ethanol production in PCS bioreactors than polypropylene-alone support (PPS) control. S. cerevisiae produced 30 g L-1 ethanol on PCS with ammonium sulfate medium in repeated batch fermentation, whereas PPS-control produced 5 g L-1 ethanol. Overall, increased productivity in low cost medium can be achieved beyond conventional fermentations using this novel bioreactor design. PMID:9439005

Demirci, A; Pometto, A L; Ho, K L

1997-10-01

141

Transformations of inorganic mercury by Candida albicans and Saccharomyces cerevisiae  

SciTech Connect

Saccharomyces cerevisiae and Candida albicans were incubated with 0.25, 0.5, or 0.75 {mu}g of Hg (as HgCl{sub 2}) per ml of Nelson's medium in the presence of trace amounts of oxygen at 28{degree}C for 12 days. Two control media were used, one without added Hg and one without yeast inoculum. Yeast cell growth was estimated after 1, 2, 3, and 8 days of incubation. The contents of organomercury in the system and of elemental mercury released from the media and collected in traps were determined at the end of the experiments. The results were as follows: (1) C. albicans was the more mercury-resistant species, but both yeast species failed to grown in the media containing 0.75 {mu}g of Hg per ml.; (2) The amounts of organomercury produced by the two species were proportional to the amount of HgCl{sub 2} added to the medium. In all cases C. albicans produced considerably larger amounts of methylmercury than S. cerevisiae; (3) The amounts of elemental Hg produced were inversely proportional to the HgCl{sub 2} level added in the case of S. cerevisiae but were all similar in the case of C. albicans;and (4) Neither organomercury nor elemental Hg was produced in any of the control media.

Yannai, S.; Berdicevsky, I.; Duek, L. (Technion-Israel Institute of Technology, Haifa (Israel))

1991-01-01

142

Variations of two pools of glycogen and carbohydrate in Saccharomyces cerevisiae grown with various ethanol concentrations.  

PubMed

Glycogen, a major reservoir of energy in Saccharomyces cerevisiae, is found to be present as soluble and membrane-bound insoluble pools. Yeast cells can store excess glycogen when grown in media with higher concentration of sugar or when subjected to nutritional stress conditions. Saccharomyces cerevisiae NCIM-3300 was grown in media having ethanol concentrations up to 12% (v/v). The effects of externally added ethanol on glycogen and other carbohydrate content of yeast were studied by using alkali digestion process. Fermentative activities of cells grown in the presence of various ethanol concentrations (2-8% v/v) exhibited increase in values of glycogen and other carbohydrate, whereas cells grown with higher concentrations of ethanol (10-12% v/v) exhibited depletion in glycogen and carbohydrate content along with decrease in cell weight. Such inhibitory effect of ethanol was also exhibited in terms of reduction in total cell count of yeast grown in media with 2-16% (v/v) ethanol and 8% (w/v) sugar. These data suggest that, as the plasma membrane is a prime target for ethanol action, membrane-bound insoluble glycogen might play a protective role in combating ethanol stress. Elevated level of cell-surface alpha-glucans in yeast grown with ethanol, as measured by using amyloglucosidase treatment, confirms the correlation between ethanol and glycogen. PMID:20373126

Dake, M S; Jadhv, J P; Patil, N B

2010-07-01

143

Comparison of heterologous xylose transporters in recombinant Saccharomyces cerevisiae  

PubMed Central

Background Baker's yeast (Saccharomyces cerevisiae) has been engineered for xylose utilization to enable production of fuel ethanol from lignocellulose raw material. One unresolved challenge is that S. cerevisiae lacks a dedicated transport system for pentose sugars, which means that xylose is transported by non-specific Hxt transporters with comparatively low transport rate and affinity for xylose. Results In this study, we compared three heterologous xylose transporters that have recently been shown to improve xylose uptake under different experimental conditions. The transporters Gxf1, Sut1 and At5g59250 from Candida intermedia, Pichia stipitis and Arabidopsis thaliana, respectively, were expressed in isogenic strains of S. cerevisiae and the transport kinetics and utilization of xylose was evaluated. Expression of the Gxf1 and Sut1 transporters led to significantly increased affinity and transport rates of xylose. In batch cultivation at 4 g/L xylose concentration, improved transport kinetics led to a corresponding increase in xylose utilization, whereas no correlation could be demonstrated at xylose concentrations greater than 15 g/L. The relative contribution of native sugar transporters to the overall xylose transport capacity was also estimated during growth on glucose and xylose. Conclusions Kinetic characterization and aerobic batch cultivation of strains expressing the Gxf1, Sut1 and At5g59250 transporters showed a direct relationship between transport kinetics and xylose growth. The Gxf1 transporter had the highest transport capacity and the highest xylose growth rate, followed by the Sut1 transporter. The range in which transport controlled the growth rate was determined to between 0 and 15 g/L xylose. The role of catabolite repression in regulation of native transporters was also confirmed by the observation that xylose transport by native S. cerevisiae transporters increased significantly during cultivation in xylose and at low glucose concentration. PMID:20236521

2010-01-01

144

Structure-Function Analysis of the C-terminal Domain of CNM67, a Core Component of the Saccharomyces cerevisiae  

E-print Network

of the Saccharomyces cerevisiae Spindle Pole Body*S Received for publication,February 1, 2011, and in revised form yeast Saccharomyces cerevisiae has served as a model system for understanding microtubule organizing and structural stability. The spindle pole body (SPB)2 of the budding yeast Saccharo- myces cerevisiae serves

Rayment, Ivan

145

Tolerance of budding yeast Saccharomyces cerevisiae to ultra high pressure  

NASA Astrophysics Data System (ADS)

Our studies on the tolerance of plants and animals against very high pressure of several GPa have been extended to a smaller sized fungus, the budding yeast Saccharomyces cerevisiae. Several pieces of budding yeast (dry yeast) were sealed in a small teflon capsule with a liquid pressure medium fluorinate, and exposed to 7.5 GPa by using a cubic anvil press. The pressure was kept constant for various duration of time from 2 to 24 h. After the pressure was released, the specimens were brought out from the teflon capsule, and they were cultivated on a potato dextrose agar. It was found that the budding yeast exposed to 7.5 GPa for up to 6 h showed multiplication. However, those exposed to 7.5 GPa for longer than 12 h were found dead. The high pressure tolerance of budding yeast is a little weaker than that of tardigrades.

Shibata, M.; Torigoe, M.; Matsumoto, Y.; Yamamoto, M.; Takizawa, N.; Hada, Y.; Mori, Y.; Takarabe, K.; Ono, F.

2014-05-01

146

Brazilian propolis protects Saccharomyces cerevisiae cells against oxidative stress  

PubMed Central

Propolis is a natural product widely used for humans. Due to its complex composition, a number of applications (antimicrobial, antiinflammatory, anesthetic, cytostatic and antioxidant) have been attributed to this substance. Using Saccharomyces cerevisiae as a eukaryotic model we investigated the mechanisms underlying the antioxidant effect of propolis from Guarapari against oxidative stress. Submitting a wild type (BY4741) and antioxidant deficient strains (ctt1?, sod1?, gsh1?, gtt1? and gtt2?) either to 15 mM menadione or to 2 mM hydrogen peroxide during 60 min, we observed that all strains, except the mutant sod1?, acquired tolerance when previously treated with 25 ?g/mL of alcoholic propolis extract. Such a treatment reduced the levels of ROS generation and of lipid peroxidation, after oxidative stress. The increase in Cu/Zn-Sod activity by propolis suggests that the protection might be acting synergistically with Cu/Zn-Sod. PMID:24516431

de Sá, Rafael A.; de Castro, Frederico A.V.; Eleutherio, Elis C.A.; de Souza, Raquel M.; da Silva, Joaquim F.M.; Pereira, Marcos D.

2013-01-01

147

Replication of Avocado Sunblotch Viroid in the Yeast Saccharomyces cerevisiae?  

PubMed Central

Viroids are the smallest known pathogenic agents. They are noncoding, single-stranded, closed-circular, “naked” RNAs, which replicate through RNA-RNA transcription. Viroids of the Avsunviroidae family possess a hammerhead ribozyme in their sequence, allowing self-cleavage during their replication. To date, viroids have only been detected in plant cells. Here, we investigate the replication of Avocado sunblotch viroid (ASBVd) of the Avsunviroidae family in a nonconventional host, the yeast Saccharomyces cerevisiae. We demonstrate that ASBVd RNA strands of both polarities are able to self-cleave and to replicate in a unicellular eukaryote cell. We show that the viroid monomeric RNA is destabilized by the nuclear 3? and the cytoplasmic 5? RNA degradation pathways. For the first time, our results provide evidence that viroids can replicate in other organisms than plants and that yeast contains all of the essential cellular elements for the replication of ASBVd. PMID:21270165

Delan-Forino, Clementine; Maurel, Marie-Christine; Torchet, Claire

2011-01-01

148

Phenotypic effects of membrane protein overexpression in Saccharomyces cerevisiae  

NASA Astrophysics Data System (ADS)

Large-scale protein overexpression phenotype screens provide an important complement to the more common gene knockout screens. Here, we have targeted the so far poorly understood Saccharomyces cerevisiae membrane proteome and report growth phenotypes for a strain collection overexpressing 600 C-terminally tagged integral membrane proteins grown both under normal and three different stress conditions. Although overexpression of most membrane proteins reduce the growth rate in synthetic defined medium, we identify a large number of proteins that, when overexpressed, confer specific resistance to various stress conditions. Our data suggest that regulation of glycosylphosphatidylinositol anchor biosynthesis and the Na+/K+ homeostasis system constitute major downstream targets of the yeast PKA/RAS pathway and point to a possible connection between the early secretory pathway and the cells' response to oxidative stress. We also have quantified the expression levels for >550 membrane proteins, facilitating the choice of well expressing proteins for future functional and structural studies. caffeine | paraquat | salt tolerance | yeast

Melén, Karin; Blomberg, Anders; von Heijne, Gunnar

2006-07-01

149

Mechanisms and Regulation of Mitotic Recombination in Saccharomyces cerevisiae  

PubMed Central

Homology-dependent exchange of genetic information between DNA molecules has a profound impact on the maintenance of genome integrity by facilitating error-free DNA repair, replication, and chromosome segregation during cell division as well as programmed cell developmental events. This chapter will focus on homologous mitotic recombination in budding yeast Saccharomyces cerevisiae. However, there is an important link between mitotic and meiotic recombination (covered in the forthcoming chapter by Hunter et al. 2015) and many of the functions are evolutionarily conserved. Here we will discuss several models that have been proposed to explain the mechanism of mitotic recombination, the genes and proteins involved in various pathways, the genetic and physical assays used to discover and study these genes, and the roles of many of these proteins inside the cell. PMID:25381364

Symington, Lorraine S.; Rothstein, Rodney; Lisby, Michael

2014-01-01

150

Global response of Saccharomyces cerevisiae to an alkylating agent  

PubMed Central

DNA chip technology enables simultaneous examination of how ?6,200 Saccharomyces cerevisiae gene transcript levels, representing the entire genome, respond to environmental change. By using chips bearing oligonucleotide arrays, we show that, after exposure to the alkylating agent methyl methanesulfonate, ?325 gene transcript levels are increased and ?76 are decreased. Of the 21 genes that already were known to be induced by a DNA-damaging agent, 18 can be scored as inducible in this data set, and surprisingly, most of the newly identified inducible genes are induced even more strongly than these 18. We examined 42 responsive and 8 nonresponsive ORFs by conventional Northern blotting, and 48 of these 50 ORFs responded as they did by DNA chip analysis, with magnitudes displaying a correlation coefficient of 0.79. Responsive genes fall into several expected and many unexpected categories. Evidence for the induction of a program to eliminate and replace alkylated proteins is presented. PMID:9990050

Jelinsky, Scott A.; Samson, Leona D.

1999-01-01

151

Characterization of Insoluble Protein Fractions of Mitochondria from Saccharomyces cerevisiae  

PubMed Central

Saccharomyces cerevisiae was grown in a chemostat in the presence of excess oxygen. Cells harvested from fully derepressed and strongly repressed steady states show typical promitochondria-like structures under conditions of strong repression. Insoluble membrane proteins were extracted from highly purified mitochondria and submitted to isoelectric focusing in 6% polyacrylamide gels. Some 20 protein bands were obtained from derepressed cells. The pattern was clearly different (quantitatively and possibly qualitatively) from repressed mitochondria. In contrast to ribosomal proteins, insoluble membrane protein fractions were found in the acid section (pH 4 to 6.8) of the ampholyte gels. It can be concluded that glucose repression plays a prominent role in the synthesis of the functional mitochondrial membranes. Images PMID:4550823

Fiechter, A.; Mian, F. A.; Ris, H.; Halvorson, H. O.

1972-01-01

152

Mutations in Ran system affected telomere silencing in Saccharomyces cerevisiae  

SciTech Connect

The Ran GTPase system regulates the direction and timing of several cellular events, such as nuclear-cytosolic transport, centrosome formation, and nuclear envelope assembly in telophase. To gain insight into the Ran system's involvement in chromatin formation, we investigated gene silencing at the telomere in several mutants of the budding yeast Saccharomyces cerevisiae, which had defects in genes involved in the Ran system. A mutation of the RanGAP gene, rna1-1, caused reduced silencing at the telomere, and partial disruption of the nuclear Ran binding factor, yrb2-{delta}2, increased this silencing. The reduced telomere silencing in rna1-1 cells was suppressed by a high dosage of the SIR3 gene or the SIT4 gene. Furthermore, hyperphosphorylated Sir3 protein accumulated in the rna1-1 mutant. These results suggest that RanGAP is required for the heterochromatin structure at the telomere in budding yeast.

Hayashi, Naoyuki [Department of Molecular Pathology, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-0934 (Japan); Department of Molecular Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-0934 (Japan)], E-mail: naoyuki@kenroku.kanazawa-u.ac.jp; Kobayashi, Masahiko; Shimizu, Hiroko; Yamamoto, Ken-ichi [Department of Molecular Pathology, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-0934 (Japan); Murakami, Seishi [Department of Molecular Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-0934 (Japan); Nishimoto, Takeharu [Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Higashi-ku, Fukuoka 812-8582 (Japan)

2007-11-23

153

The Influence of Microgravity on Invasive Growth in Saccharomyces cerevisiae  

NASA Astrophysics Data System (ADS)

This study investigates the effects of microgravity on colony growth and the morphological transition from single cells to short invasive filaments in the model eukaryotic organism Saccharomyces cerevisiae. Two-dimensional spreading of the yeast colonies grown on semi-solid agar medium was reduced under microgravity in the ?1278b laboratory strain but not in the CMBSESA1 industrial strain. This was supported by the ?1278b proteome map under microgravity conditions, which revealed upregulation of proteins linked to anaerobic conditions. The ?1278b strain showed a reduced invasive growth in the center of the yeast colony. Bud scar distribution was slightly affected, with a switch toward more random budding. Together, microgravity conditions disturb spatially programmed budding patterns and generate strain-dependent growth differences in yeast colonies on semi-solid medium.

Van Mulders, Sebastiaan E.; Stassen, Catherine; Daenen, Luk; Devreese, Bart; Siewers, Verena; van Eijsden, Rudy G. E.; Nielsen, Jens; Delvaux, Freddy R.; Willaert, Ronnie

2011-01-01

154

Reconstruction and logical modeling of glucose repression signaling pathways in Saccharomyces cerevisiae  

E-print Network

Background: In the yeast Saccharomyces cerevisiae, the presence of high levels of glucose leads to an array of down-regulatory effects known as glucose repression. This process is complex due to the presence of feedback ...

Oliveira, Ana Paula

155

Defining the active form of ribonucleotide reductase from Saccharomyces cerevisiae in vitro and in vivo  

E-print Network

Ribonucleotide reductase (RNR) catalyzes the conversion of ribonucleotides to deoxyribonucleotides. Saccharomyces cerevisiae RNR is a class I RNR composed of a dimeric large subunit (RI), containing the active site and ...

Perlstein, Deborah Leigh

2005-01-01

156

Tracking the Herd: Resynchronization Analysis of Cell-Cycle Gene Expression Data in Saccharomyces Cerevisiae  

E-print Network

Tracking the Herd: Resynchronization Analysis of Cell-Cycle Gene Expression Data in Saccharomyces Cerevisiae Peng Qiu, Z. Jane Wang2, and K. J. Ray Liu Department of Electrical and Computer Engineering

Liu, K. J. Ray

157

Water treatment process and system for metals removal using Saccharomyces cerevisiae  

DOEpatents

A process and a system for removal of metals from ground water or from soil by bioreducing or bioaccumulating the metals using metal tolerant microorganisms Saccharomyces cerevisiae. Saccharomyces cerevisiae is tolerant to the metals, able to bioreduce the metals to the less toxic state and to accumulate them. The process and the system is useful for removal or substantial reduction of levels of chromium, molybdenum, cobalt, zinc, nickel, calcium, strontium, mercury and copper in water.

Krauter, Paula A. W. (Livermore, CA); Krauter, Gordon W. (Livermore, CA)

2002-01-01

158

Fermentation Temperature Modulates Phosphatidylethanolamine and Phosphatidylinositol Levels in the Cell Membrane of Saccharomyces cerevisiae  

PubMed Central

During alcoholic fermentation, Saccharomyces cerevisiae is exposed to a host of environmental and physiological stresses. Extremes of fermentation temperature have previously been demonstrated to induce fermentation arrest under growth conditions that would otherwise result in complete sugar utilization at “normal” temperatures and nutrient levels. Fermentations were carried out at 15°C, 25°C, and 35°C in a defined high-sugar medium using three Saccharomyces cerevisiae strains with diverse fermentation characteristics. The lipid composition of these strains was analyzed at two fermentation stages, when ethanol levels were low early in stationary phase and in late stationary phase at high ethanol concentrations. Several lipids exhibited dramatic differences in membrane concentration in a temperature-dependent manner. Principal component analysis (PCA) was used as a tool to elucidate correlations between specific lipid species and fermentation temperature for each yeast strain. Fermentations carried out at 35°C exhibited very high concentrations of several phosphatidylinositol species, whereas at 15°C these yeast strains exhibited higher levels of phosphatidylethanolamine and phosphatidylcholine species with medium-chain fatty acids. Furthermore, membrane concentrations of ergosterol were highest in the yeast strain that experienced stuck fermentations at all three temperatures. Fluorescence anisotropy measurements of yeast cell membrane fluidity during fermentation were carried out using the lipophilic fluorophore diphenylhexatriene. These measurements demonstrate that the changes in the lipid composition of these yeast strains across the range of fermentation temperatures used in this study did not significantly affect cell membrane fluidity. However, the results from this study indicate that fermenting S. cerevisiae modulates its membrane lipid composition in a temperature-dependent manner. PMID:23811519

Henderson, Clark M.; Zeno, Wade F.; Lerno, Larry A.; Longo, Marjorie L.

2013-01-01

159

Cloning of ?12- and ?6-desaturases from Mortierella alpina and recombinant production of ?-linolenic acid in Saccharomyces cerevisiae  

Microsoft Academic Search

Two cDNA clones with homology to known desaturase genes were isolated from the fungus Mortierella alpina. The open reading frame in one clone encoded 399 amino acids and exhibited ?12-desaturase activity when expressed in Saccharomyces cerevisiae in the presence of endogenous fatty acid substrate oleic acid. The insert in another clone contained an open reading frame\\u000a encoding 457 amino acids

Yung-Sheng Huang; Sunita Chaudhary; Jennifer M. Thurmond; Emil G. Bobik; Ling Yuan; George M. Chan; Stephen J. Kirchner; Pradip Mukerji; Deborah S. Knutzon

1999-01-01

160

A metacaspase of Trypanosoma brucei causes loss of respiration competence and clonal death in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

Metacaspases constitute a new group of cysteine proteases homologous to caspases. Heterologous expression of Trypanosoma brucei metacaspase TbMCA4 in the budding yeast Saccharomyces cerevisiae resulted in growth inhibition, mitochondrial dysfunction and clonal death. The metacaspase orthologue of yeast, ScMCA1 (YOR197w), exhibited genetic interaction with WWM1 (YFL010c), which encodes a small WW domain protein. WWM1 overexpression resulted in growth arrest and

Alexander Szallies; Bruno K. Kubata; Michael Duszenko

2002-01-01

161

The mannoprotein of Saccharomyces cerevisiae is an effective bioemulsifier.  

PubMed Central

The mannoprotein which is a major component of the cell wall of Saccharomyces cerevisiae is an effective bioemulsifier. Mannoprotein emulsifier was extracted in a high yield from whole cells of fresh bakers' yeast by two methods, by autoclaving in neutral citrate buffer and by digestion with Zymolase (Miles Laboratories; Toronto, Ontario, Canada), a beta-1,3-glucanase. Heat-extracted emulsifier was purified by ultrafiltration and contained approximately 44% carbohydrate (mannose) and 17% protein. Treatment of the emulsifier with protease eliminated emulsification. Kerosene-in-water emulsions were stabilized over a broad range of conditions, from pH 2 to 11, with up to 5% sodium chloride or up to 50% ethanol in the aqueous phase. In the presence of a low concentration of various solutes, emulsions were stable to three cycles of freezing and thawing. An emulsifying agent was extracted from each species or strain of yeast tested, including 13 species of genera other than Saccharomyces. Spent yeast from the manufacture of beer and wine was demonstrated to be a possible source for the large-scale production of this bioemulsifier. PMID:3046488

Cameron, D R; Cooper, D G; Neufeld, R J

1988-01-01

162

Sweet wine production by two osmotolerant Saccharomyces cerevisiae strains.  

PubMed

The use of Saccharomyces cerevisiae to produce sweet wine is difficult because yeast is affected by a hyperosmotic stress due to the high sugar concentrations in the fermenting must. One possible alternative could be the coimmobilization of the osmotolerant yeast strains S. cerevisiae X4 and X5 on Penicillium chrysogenum strain H3 (GRAS) for the partial fermentation of raisin musts. This immobilized has been, namely, as yeast biocapsules. Traditional sweet wine (that is, without fermentation of the must) and must partially fermented by free yeast cells were also used for comparison. Partially fermented sweet wines showed higher concentration of the volatile compounds than traditionally produced wines. The wines obtained by immobilized yeast cells reached minor concentrations of major alcohols than wines by free cells. The consumption of specific nitrogen compounds was dependent on yeast strain and the cellular immobilization. A principal component analysis shows that the compounds related to the response to osmotic stress (glycerol, acetaldehyde, acetoin, and butanediol) clearly differentiate the wines obtained with free yeasts but not the wines obtained with immobilized yeasts. PMID:23601087

García-Martínez, Teresa; de Lerma, Nieves López; Moreno, Juan; Peinado, Rafael A; Millán, M Carmen; Mauricio, Juan C

2013-06-01

163

Genomic Evolution of Saccharomyces cerevisiae under Chinese Rice Wine Fermentation  

PubMed Central

Rice wine fermentation represents a unique environment for the evolution of the budding yeast, Saccharomyces cerevisiae. To understand how the selection pressure shaped the yeast genome and gene regulation, we determined the genome sequence and transcriptome of a S. cerevisiae strain YHJ7 isolated from Chinese rice wine (Huangjiu), a popular traditional alcoholic beverage in China. By comparing the genome of YHJ7 to the lab strain S288c, a Japanese sake strain K7, and a Chinese industrial bioethanol strain YJSH1, we identified many genomic sequence and structural variations in YHJ7, which are mainly located in subtelomeric regions, suggesting that these regions play an important role in genomic evolution between strains. In addition, our comparative transcriptome analysis between YHJ7 and S288c revealed a set of differentially expressed genes, including those involved in glucose transport (e.g., HXT2, HXT7) and oxidoredutase activity (e.g., AAD10, ADH7). Interestingly, many of these genomic and transcriptional variations are directly or indirectly associated with the adaptation of YHJ7 strain to its specific niches. Our molecular evolution analysis suggested that Japanese sake strains (K7/UC5) were derived from Chinese rice wine strains (YHJ7) at least approximately 2,300 years ago, providing the first molecular evidence elucidating the origin of Japanese sake strains. Our results depict interesting insights regarding the evolution of yeast during rice wine fermentation, and provided a valuable resource for genetic engineering to improve industrial wine-making strains. PMID:25212861

Li, Yudong; Zhang, Weiping; Zheng, Daoqiong; Zhou, Zhan; Yu, Wenwen; Zhang, Lei; Feng, Lifang; Liang, Xinle; Guan, Wenjun; Zhou, Jingwen; Chen, Jian; Lin, Zhenguo

2014-01-01

164

Suppression of nuclear oscillations in Saccharomyces cerevisiae expressing Glu tubulin  

PubMed Central

In most eukaryotic cells, the C-terminal amino acid of ?-tubulin is aromatic (Tyr in mammals and Phe in Saccharomyces cerevisiae) and is preceded by two glutamate residues. In mammals, the C-terminal Tyr of ?-tubulin is subject to cyclic removal from the peptide chain by a carboxypeptidase and readdition to the chain by a tubulin–Tyr ligase. There is evidence that tubulin–Tyr ligase suppression and the resulting accumulation of detyrosinated (Glu) tubulin favor tumor growth, both in animal models and in human cancers. However, the molecular basis for this apparent stimulatory effect of Glu tubulin accumulation on tumor progression is unknown. Here we have developed S. cerevisiae strains expressing only Glu tubulin and used them as a model to assess the consequences of Glu tubulin accumulation in cells. We find that Glu tubulin strains show defects in nuclear oscillations. These defects are linked to a markedly decreased association of the yeast ortholog of CLIP170, Bik1p, with microtubule plus-ends. These results indicate that the accumulation of Glu tubulin in cells affects microtubule tip complexes that are important for microtubule interactions with the cell cortex. PMID:15031428

Badin-Larcon, A. C.; Boscheron, C.; Soleilhac, J. M.; Piel, M.; Mann, C.; Denarier, E.; Fourest-Lieuvin, A.; Lafanechere, L.; Bornens, M.; Job, D.

2004-01-01

165

Heterologous Production of Dihomo-?-Linolenic Acid in Saccharomyces cerevisiae?  

PubMed Central

To make dihomo-?-linolenic acid (DGLA) (20:3n-6) in Saccharomyces cerevisiae, we introduced Kluyveromyces lactis ?12 fatty acid desaturase, rat ?6 fatty acid desaturase, and rat elongase genes. Because Fad2p is able to convert the endogenous oleic acid to linoleic acid, this allowed DGLA biosynthesis without the need to supply exogenous fatty acids on the media. Medium composition, cultivation temperature, and incubation time were examined to improve the yield of DGLA. Fatty acid content was increased by changing the medium from a standard synthetic dropout medium to a nitrogen-limited minimal medium (NSD). Production of DGLA was higher in the cells grown at 15°C than in those grown at 20°C, and no DGLA production was observed in the cells grown at 30°C. In NSD at 15°C, fatty acid content increased up until day 7 and decreased after day 10. When the cells were grown in NSD for 7 days at 15°C, the yield of DGLA reached 2.19 ?g/mg of cells (dry weight) and the composition of DGLA to total fatty acids was 2.74%. To our knowledge, this is the first report describing the production of polyunsaturated fatty acids in S. cerevisiae without supplying the exogenous fatty acids. PMID:17873077

Yazawa, Hisashi; Iwahashi, Hitoshi; Kamisaka, Yasushi; Kimura, Kazuyoshi; Aki, Tsunehiro; Ono, Kazuhisa; Uemura, Hiroshi

2007-01-01

166

Exploring the northern limit of the distribution of Saccharomyces cerevisiae and Saccharomyces paradoxus in North America.  

PubMed

We examined the northern limit of Saccharomyces cerevisiae and Saccharomyces paradoxus in northeast America. We collected 876 natural samples at 29 sites and applied enrichment methods for the isolation of mesophilic yeasts. We uncovered a large diversity of yeasts, in some cases, associated with specific substrates. Sequencing of the ITS1, 5.8S and ITS2 loci allowed to assign 226 yeast strains at the species level, including 41 S. paradoxus strains. Our intensive sampling suggests that if present, S. cerevisiae is rare at these northern latitudes. Our sampling efforts spread across several months of the year revealed that successful sampling increases throughout the summer and diminishes significantly at the beginning of the fall. The data obtained on the ecological context of yeasts corroborate what was previously reported on Pichiaceae, Saccharomycodaceae, Debaryomycetaceae and Phaffomycetaceae yeast families. We identified 24 yeast isolates that could not be assigned to any known species and that may be of taxonomic, medical, or biotechnological importance. Our study reports new data on the taxonomic diversity of yeasts and new resources for studying the evolution and ecology of S. paradoxus. PMID:24119009

Charron, Guillaume; Leducq, Jean-Baptiste; Bertin, Chloé; Dubé, Alexandre K; Landry, Christian R

2014-03-01

167

High level secretion of cellobiohydrolases by Saccharomyces cerevisiae  

PubMed Central

Background The main technological impediment to widespread utilization of lignocellulose for the production of fuels and chemicals is the lack of low-cost technologies to overcome its recalcitrance. Organisms that hydrolyze lignocellulose and produce a valuable product such as ethanol at a high rate and titer could significantly reduce the costs of biomass conversion technologies, and will allow separate conversion steps to be combined in a consolidated bioprocess (CBP). Development of Saccharomyces cerevisiae for CBP requires the high level secretion of cellulases, particularly cellobiohydrolases. Results We expressed various cellobiohydrolases to identify enzymes that were efficiently secreted by S. cerevisiae. For enhanced cellulose hydrolysis, we engineered bimodular derivatives of a well secreted enzyme that naturally lacks the carbohydrate-binding module, and constructed strains expressing combinations of cbh1 and cbh2 genes. Though there was significant variability in the enzyme levels produced, up to approximately 0.3 g/L CBH1 and approximately 1 g/L CBH2 could be produced in high cell density fermentations. Furthermore, we could show activation of the unfolded protein response as a result of cellobiohydrolase production. Finally, we report fermentation of microcrystalline cellulose (Avicel™) to ethanol by CBH-producing S. cerevisiae strains with the addition of beta-glucosidase. Conclusions Gene or protein specific features and compatibility with the host are important for efficient cellobiohydrolase secretion in yeast. The present work demonstrated that production of both CBH1 and CBH2 could be improved to levels where the barrier to CBH sufficiency in the hydrolysis of cellulose was overcome. PMID:21910902

2011-01-01

168

Enhanced meiotic recombination on the smallest chromosome of Saccharomyces cerevisiae.  

PubMed Central

Chromosome I is the smallest chromosome in Saccharomyces cerevisiae and contains a DNA molecule that is only 250 kilobases (kb). Approximately 75% of this DNA molecule has been cloned. A restriction map for the entire DNA molecule from chromosome I was determined and most of its genetically mapped genes were located on this physical map. Based on the average rate of recombination (centimorgans/kb) found for other S. cerevisiae chromosomes, the outermost markers on the genetic map of chromosome I were expected to be close to the ends of the DNA molecule. While the rightmost genetic marker was 3 kb from the end, the leftmost marker, CDC24, was located near the middle of the left arm, suggesting that the genetic map would be much longer. To extend the genetic map, a copy of the S. cerevisiae URA3 gene was integrated in the outermost cloned region located 32 kb centromere distal to CDC24, and the genetic map distance between these two genes was determined. The new marker substantially increased the genetic map length of chromosome I. In addition, we determined the relationship between physical and genetic map distance along most of the length of the chromosome. Consistent with the longer genetic map, the average rate of recombination between markers on chromosome I was greater than 50% higher than the average found on other yeast chromosomes. Owing to its small size, it had been estimated that approximately 5% of the chromosome I homologues failed to undergo meiotic recombination. New measurements of the zero-crossover class indicated that the enhanced rate of recombination ensures at least one genetic exchange between virtually every pair of chromosome I homologues. PMID:2657726

Kaback, D B; Steensma, H Y; de Jonge, P

1989-01-01

169

Role of social wasps in Saccharomyces cerevisiae ecology and evolution  

PubMed Central

Saccharomyces cerevisiae is one of the most important model organisms and has been a valuable asset to human civilization. However, despite its extensive use in the last 9,000 y, the existence of a seasonal cycle outside human-made environments has not yet been described. We demonstrate the role of social wasps as vector and natural reservoir of S. cerevisiae during all seasons. We provide experimental evidence that queens of social wasps overwintering as adults (Vespa crabro and Polistes spp.) can harbor yeast cells from autumn to spring and transmit them to their progeny. This result is mirrored by field surveys of the genetic variability of natural strains of yeast. Microsatellites and sequences of a selected set of loci able to recapitulate the yeast strain’s evolutionary history were used to compare 17 environmental wasp isolates with a collection of strains from grapes from the same region and more than 230 strains representing worldwide yeast variation. The wasp isolates fall into subclusters representing the overall ecological and industrial yeast diversity of their geographic origin. Our findings indicate that wasps are a key environmental niche for the evolution of natural S. cerevisiae populations, the dispersion of yeast cells in the environment, and the maintenance of their diversity. The close relatedness of several wasp isolates with grape and wine isolates reflects the crucial role of human activities on yeast population structure, through clonal expansion and selection of specific strains during the biotransformation of fermented foods, followed by dispersal mediated by insects and other animals. PMID:22847440

Stefanini, Irene; Dapporto, Leonardo; Legras, Jean-Luc; Calabretta, Antonio; Di Paola, Monica; De Filippo, Carlotta; Viola, Roberto; Capretti, Paolo; Polsinelli, Mario; Turillazzi, Stefano; Cavalieri, Duccio

2012-01-01

170

Physiological adaptations of Saccharomyces cerevisiae evolved for improved butanol tolerance  

PubMed Central

Background Butanol is a chemical with potential uses as biofuel and solvent, which can be produced by microbial fermentation. However, the end product toxicity is one of the main obstacles for developing the production process irrespective of the choice of production organism. The long-term goal of the present project is to produce 2-butanol in Saccharomyces cerevisiae. Therefore, unraveling the toxicity mechanisms of solvents such as butanol and understanding the mechanisms by which tolerant strains of S. cerevisiae adapt to them would be an important contribution to the development of a bio-based butanol production process. Results A butanol tolerant S. cerevisiae was achieved through a series of sequential batch cultures with gradual increase of 2-butanol concentration. The final mutant (JBA-mut) tolerates all different alcohols tested at higher concentrations compared to the wild type (JBA-wt). Proteomics analysis of the two strains grown under mild butanol-stress revealed 46 proteins changing their expression by more than 1.5-fold in JBA-mut, 34 of which were upregulated. Strikingly, 21 out of the 34 upregulated proteins were predicted constituents of mitochondria. Among the non-mitochondrial up-regulated proteins, the minor isoform of Glycerol-3-phosphatase (Gpp2) was the most notable, since it was the only tested protein whose overexpression was found to confer butanol tolerance. Conclusion The study demonstrates several differences between the butanol tolerant mutant and the wild type. Upregulation of proteins involved in the mitochondrial ATP synthesizing machinery constituents and glycerol biosynthesis seem to be beneficial for a successful adaptation of yeast cells to butanol stress. PMID:23855998

2013-01-01

171

Effects of fermentation temperature on the strain population of Saccharomyces cerevisiae  

Microsoft Academic Search

The influence of fermentation temperature (from 15 to 35 jC) on a mixed strain population was studied. Mitochondrial DNA analysis was used to differentiate Saccharomyces cerevisiae strains and the frequency of each strain during the alcoholic fermentation was determined. The chemical analyses of resulting wines were carried out. The temperature determined how Saccharomyces strains developed and how effectively they fermented.

Nicolas Rozes; Montse Poblet; Albert Mas

172

Effects of fermentation temperature on the strain population of Saccharomyces cerevisiae  

Microsoft Academic Search

The influence of fermentation temperature (from 15 to 35 °C) on a mixed strain population was studied. Mitochondrial DNA analysis was used to differentiate Saccharomyces cerevisiae strains and the frequency of each strain during the alcoholic fermentation was determined. The chemical analyses of resulting wines were carried out. The temperature determined how Saccharomyces strains developed and how effectively they fermented.

Ma. Jesús Torija; Nicolas Rozès; Montse Poblet; José Manuel Guillamón; Albert Mas

2003-01-01

173

The use of genetically modified Saccharomyces cerevisiae strains in the wine industry  

Microsoft Academic Search

In recent decades, science and food technology have contributed at an accelerated rate to the introduction of new products to satisfy nutritional, socio-economic and quality requirements. With the emergence of modern molecular genetics, the industrial importance of Saccharomyces cerevisiae, is continuously extended. The demand for suitable genetically modified (GM) S. cerevisiae strains for the biofuel, bakery and beverage industries or

Dorit Schuller; Margarida Casal

2005-01-01

174

Effects of cyclohexane, an industrial solvent, on the yeast Saccharomyces cerevisiae and on isolated yeast mitochondria  

Microsoft Academic Search

Little information on the effects of cyclohexane at the cellular or subcellular level is available. In Saccharomyces cerevisiae, cyclohexane inhibited respiration and diverse energy-dependent processes. In mitochondria isolated from S. cerevisiae, oxygen uptake and ATP synthesis were inhibited, although ATPase activity was not affected. Cyclohexane effects were similar to those reported for beta-pinene and limonene, suggesting that the cyclohexane ring

S. Uribe; P. Rangel; G. Espinola; G. Aguirre

1990-01-01

175

Invertase SUC2 Is the Key Hydrolase for Inulin Degradation in Saccharomyces cerevisiae  

PubMed Central

Specific Saccharomyces cerevisiae strains were recently found to be capable of efficiently utilizing inulin, but genetic mechanisms of inulin hydrolysis in yeast remain unknown. Here we report functional characteristics of invertase SUC2 from strain JZ1C and demonstrate that SUC2 is the key enzyme responsible for inulin metabolism in S. cerevisiae. PMID:23104410

Wang, Shi-An

2013-01-01

176

In vivo analysis of cohesin architecture using FRET in the budding yeast Saccharomyces cerevisiae  

E-print Network

EMBO open In vivo analysis of cohesin architecture using FRET in the budding yeast Saccharomyces cerevisiae This is an open-access article distributed under the terms of the Creative Commons Attribution. cerevisiae; Smc proteins Introduction Cohesin is member of the family of Smc (structural main- tenance

Davis, Trisha N.

177

Mixing of vineyard and oak-tree ecotypes of Saccharomyces cerevisiae in North American vineyards  

E-print Network

Mixing of vineyard and oak-tree ecotypes of Saccharomyces cerevisiae in North American vineyards are genetically differentiated from strains isolated from oak- tree bark, exudate and associated soil in North groups. We examined S. cerevisiae strains isolated from grapes and oak trees within three North American

Fay, Justin

178

NATURE GENETICS | VOLUME 39 | NUMBER 3 | MARCH 2007 303 A genome-wide analysis in Saccharomyces cerevisiae  

E-print Network

in Saccharomyces cerevisiae demonstrates the influence of chromatin modifiers on transcription Israel Steinfeld1 methodology to S. cerevisiae, using a compendium of 170 gene expression profiles of strains defective

Shamir, Ron

179

Saccharomyces Genome Database (SGD) provides tools to identify and analyze sequences from Saccharomyces cerevisiae and related sequences from other organisms  

Microsoft Academic Search

The Saccharomyces Genome Database (SGD; http:\\/\\/ www.yeastgenome.org\\/), a scientific database of the molecular biology and genetics of the yeast Saccharomyces cerevisiae, has recently developed several new resources that allow the comparison and integration of information on a genome-wide scale, enabling the user not only to find detailed information about individual genes, but also to make connections across groups of genes

Karen R. Christie; Shuai Weng; Rama Balakrishnan; Maria C. Costanzo; Kara Dolinski; Selina S. Dwight; Stacia R. Engel; Becket Feierbach; Dianna G. Fisk; Jodi E. Hirschman; Eurie L. Hong; Laurie Issel-tarver; Robert S. Nash; Anand Sethuraman; Barry Starr; Chandra L. Theesfeld; Rey Andrada; Gail Binkley; Qing Dong; Mark Schroeder; David Botstein; J. Michael Cherry

2004-01-01

180

Construction of a flocculent Saccharomyces cerevisiae strain secreting high levels of Aspergillus niger ?-galactosidase  

Microsoft Academic Search

A flocculent Saccharomyces cerevisiae strain secreting Aspergillus niger ?-galactosidase activity was constructed by transforming S. cerevisiae NCYC869-A3 strain with plasmid pVK1.1 harboring the A. niger ?-ga- lactosidase gene, lacA, under the control of the ADH1 promoter and terminator. Compared to other recombinant S. cerevisiae strains, this recombinant yeast has higher levels of extracellular ?-galactosidase activity. In shake- flask cultures, the

J. A. Teixeira; M. Penttilä; N. Lima

2002-01-01

181

A genetic overhaul of Saccharomyces cerevisiae 424A(LNH-ST) to improve xylose fermentation  

Microsoft Academic Search

Robust microorganisms are necessary for economical bioethanol production. However, such organisms must be able to effectively\\u000a ferment both hexose and pentose sugars present in lignocellulosic hydrolysate to ethanol. Wild type Saccharomyces cerevisiae can rapidly ferment hexose, but cannot ferment pentose sugars. Considerable efforts were made to genetically engineer S. cerevisiae to ferment xylose. Our genetically engineered S cerevisiae yeast, 424A(LNH-ST),

Aloke K. Bera; Nancy W. Y. Ho; Aftab Khan; Miroslav Sedlak

2011-01-01

182

Metabolism of sulfur amino acids in Saccharomyces cerevisiae.  

PubMed Central

Sulfur amino acid biosynthesis in Saccharomyces cerevisiae involves a large number of enzymes required for the de novo biosynthesis of methionine and cysteine and the recycling of organic sulfur metabolites. This review summarizes the details of these processes and analyzes the molecular data which have been acquired in this metabolic area. Sulfur biochemistry appears not to be unique through terrestrial life, and S. cerevisiae is one of the species of sulfate-assimilatory organisms possessing a larger set of enzymes for sulfur metabolism. The review also deals with several enzyme deficiencies that lead to a nutritional requirement for organic sulfur, although they do not correspond to defects within the biosynthetic pathway. In S. cerevisiae, the sulfur amino acid biosynthetic pathway is tightly controlled: in response to an increase in the amount of intracellular S-adenosylmethionine (AdoMet), transcription of the coregulated genes is turned off. The second part of the review is devoted to the molecular mechanisms underlying this regulation. The coordinated response to AdoMet requires two cis-acting promoter elements. One centers on the sequence TCACGTG, which also constitutes a component of all S. cerevisiae centromeres. Situated upstream of the sulfur genes, this element is the binding site of a transcription activation complex consisting of a basic helix-loop-helix factor, Cbf1p, and two basic leucine zipper factors, Met4p and Met28p. Molecular studies have unraveled the specific functions for each subunit of the Cbf1p-Met4p-Met28p complex as well as the modalities of its assembly on the DNA. The Cbf1p-Met4p-Met28p complex contains only one transcription activation module, the Met4p subunit. Detailed mutational analysis of Met4p has elucidated its functional organization. In addition to its activation and bZIP domains, Met4p contains two regulatory domains, called the inhibitory region and the auxiliary domain. When the level of intracellular AdoMet increases, the transcription activation function of Met4 is prevented by Met30p, which binds to the Met4 inhibitory region. In addition to the Cbf1p-Met4p-Met28p complex, transcriptional regulation involves two zinc finger-containing proteins, Met31p and Met32p. The AdoMet-mediated control of the sulfur amino acid pathway illustrates the molecular strategies used by eucaryotic cells to couple gene expression to metabolic changes. PMID:9409150

Thomas, D; Surdin-Kerjan, Y

1997-01-01

183

Raw starch conversion by Saccharomyces cerevisiae expressing Aspergillus tubingensis amylases  

PubMed Central

Background Starch is one of the most abundant organic polysaccharides available for the production of bio-ethanol as an alternative transport fuel. Cost-effective utilisation of starch requires consolidated bioprocessing (CBP) where a single microorganism can produce the enzymes required for hydrolysis of starch, and also convert the glucose monomers to ethanol. Results The Aspergillus tubingensis T8.4 ?-amylase (amyA) and glucoamylase (glaA) genes were cloned and expressed in the laboratory strain Saccharomyces cerevisiae Y294 and the semi-industrial strain, S. cerevisiae Mnu?1. The recombinant AmyA and GlaA displayed protein sizes of 110–150 kDa and 90 kDa, respectively, suggesting significant glycosylation in S. cerevisiae. The Mnu?1[AmyA-GlaA] and Y294[AmyA-GlaA] strains were able to utilise 20 g l-1 raw corn starch as sole carbohydrate source, with ethanol titers of 9.03 and 6.67 g l-1 (0.038 and 0.028 g l-1 h-1), respectively, after 10 days. With a substrate load of 200 g l-1 raw corn starch, Mnu?1[AmyA-GlaA] yielded 70.07 g l-1 ethanol (0.58 g l-1 h-1) after 120 h of fermentation, whereas Y294[AmyA-GlaA] was less efficient at 43.33 g l-1 ethanol (0.36 g l-1 h-1). Conclusions In a semi-industrial amylolytic S. cerevisiae strain expressing the A. tubingensis ?-amylase and glucoamylase genes, 200 g l-1 raw starch was completely hydrolysed (saccharified) in 120 hours with 74% converted to released sugars plus fermentation products and the remainder presumably to biomass. The single-step conversion of raw starch represents significant progress towards the realisation of CBP without the need for any heat pretreatment. Furthermore, the amylases were produced and secreted by the host strain, thus circumventing the need for exogenous amylases. PMID:24286270

2013-01-01

184

Opuntia ficus-indica cladodes as feedstock for ethanol production by Kluyveromyces marxianus and Saccharomyces cerevisiae.  

PubMed

The feasibility of ethanol production using an enzymatic hydrolysate of pretreated cladodes of Opuntia ficus-indica (prickly pear cactus) as carbohydrate feedstock was investigated, including a comprehensive chemical analysis of the cladode biomass and the effects of limited aeration on the fermentation profiles and sugar utilization. The low xylose and negligible mannose content of the cladode biomass used in this study suggested that the hemicellulose structure of the O. ficus-indica cladode was atypical of hardwood or softwood hemicelluloses. Separate hydrolysis and fermentation and simultaneous saccharification and fermentation procedures using Kluyveromyces marxianus and Saccharomyces cerevisiae at 40 and 35 °C, respectively, gave similar ethanol yields under non-aerated conditions. In oxygen-limited cultures K. marxianus exhibited almost double the ethanol productivity compared to non-aerated cultures, although after sugar depletion utilization of the produced ethanol was evident. Ethanol concentrations of up to 19.5 and 20.6 g l(-1) were obtained with K. marxianus and S. cerevisiae, respectively, representing 66 and 70 % of the theoretical yield on total sugars in the hydrolysate. Because of the low xylan content of the cladode biomass, a yeast capable of xylose fermentation might not be a prerequisite for ethanol production. K. marxianus, therefore, has potential as an alternative to S. cerevisiae for bioethanol production. However, the relatively low concentration of fermentable sugars in the O. ficus-indica cladode hydrolysate presents a technical constraint for commercial exploitation. PMID:25248867

Kuloyo, Olukayode O; du Preez, James C; García-Aparicio, Maria Del Prado; Kilian, Stephanus G; Steyn, Laurinda; Görgens, Johann

2014-12-01

185

Identification of genes required for growth under ethanol stress using transposon mutagenesis in Saccharomyces cerevisiae.  

PubMed

The yeast Saccharomyces cerevisiae exhibits high ethanol tolerance compared with other microorganisms. The mechanism of ethanol tolerance in yeast is thought to be regulated by many genes. To identify some of these genes, we screened for ethanol-sensitive S. cerevisiae strains among a collection of mutants obtained using transposon mutagenesis. Five ethanol-sensitive (ets) mutants were isolated from approximately 7,000 mutants created by transforming yeast cells with a transposon (mTn-lacZ/LEU2)-mutagenized genomic library. Although these mutants grew normally in a rich medium, they could not grow in the same medium containing 6% ethanol. Sequence analysis of the ets mutants revealed that the transposon was inserted in the coding regions of BEM2, PAT1, ROM2, VPS34 and ADA2. We constructed deletion mutants for these genes by a PCR-directed disruption method and confirmed that the disruptants, like the ets mutants, were ethanol sensitive. Thus, these five genes are indeed required for growth under ethanol stress. These mutants were also more sensitive than normal cells to Calcofluor white, a drug that affects cell wall architecture, and Zymolyase, a yeast lytic enzyme containing mainly beta-1,3- glucanase, indicating that the integrity of the cell wall plays an important role in ethanol tolerance in S. cerevisiae. PMID:11523784

Takahashi, T; Shimoi, H; Ito, K

2001-08-01

186

V-ATPase dysfunction suppresses polyphosphate synthesis in Saccharomyces cerevisiae.  

PubMed

The yeast Saccharomyces cerevisiae accumulates the high levels of inorganic polyphosphates (polyPs) performing in the cells numerous functions, including phosphate and energy storage. The effects of vacuolar membrane ATPase (V-ATPase) dysfunction were studied on polyP accumulation under short-term cultivation in the Pi-excess media after Pi starvation. The addition of bafilomycin A1, a specific inhibitor of V-ATPase, to the medium with glucose resulted in strong inhibition of the synthesis of long-chain polyP and in substantial suppression of short-chain polyP. The addition of bafilomycin to the medium with ethanol resulted in decreased accumulation of high-molecular polyP, while the accumulation of low-molecular polyP was not affected. The levels of polyP synthesis in the mutant strain with a deletion in the vma2 gene encoding a V-ATPase subunit were significantly lower than in the parent strain in the media with glucose and with ethanol. The synthesis of the longest chain polyP was not observed in the mutant cells. The synthesis of only the low-polymer acid-soluble polyP fraction occurred in the cells of the mutant strain. However, the level of polyP1 was nearly tenfold lower than compared to the cells of the parent strain. Both bafilomycin A1 and the mutation in vacuolar ATPase subunit vma2 lead to a considerable decrease of cellular polyP accumulation. Thus, the defects in ??H(+) formation on the vacuolar membrane resulted in the decrease of polyP biosynthesis in S. cerevisiae. PMID:23371743

Trilisenko, Ludmila; Tomashevsky, Alexander; Kulakovskaya, Tatiana; Kulaev, Igor

2013-11-01

187

Introducing a New Breed of Wine Yeast: Interspecific Hybridisation between a Commercial Saccharomyces cerevisiae Wine Yeast and Saccharomyces mikatae  

PubMed Central

Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment. PMID:23614011

Bellon, Jennifer R.; Schmid, Frank; Capone, Dimitra L.; Dunn, Barbara L.; Chambers, Paul J.

2013-01-01

188

Regulation of xylose metabolism in recombinant Saccharomyces cerevisiae  

PubMed Central

Background Considerable interest in the bioconversion of lignocellulosic biomass into ethanol has led to metabolic engineering of Saccharomyces cerevisiae for fermentation of xylose. In the present study, the transcriptome and proteome of recombinant, xylose-utilising S. cerevisiae grown in aerobic batch cultures on xylose were compared with those of glucose-grown cells both in glucose repressed and derepressed states. The aim was to study at the genome-wide level how signalling and carbon catabolite repression differ in cells grown on either glucose or xylose. The more detailed knowledge whether xylose is sensed as a fermentable carbon source, capable of catabolite repression like glucose, or is rather recognised as a non-fermentable carbon source is important for further engineering this yeast for more efficient anaerobic fermentation of xylose. Results Genes encoding respiratory proteins, proteins of the tricarboxylic acid and glyoxylate cycles, and gluconeogenesis were only partially repressed by xylose, similar to the genes encoding their transcriptional regulators HAP4, CAT8 and SIP1-2 and 4. Several genes that are repressed via the Snf1p/Mig1p-pathway during growth on glucose had higher expression in the cells grown on xylose than in the glucose repressed cells but lower than in the glucose derepressed cells. The observed expression profiles of the transcription repressor RGT1 and its target genes HXT2-3, encoding hexose transporters suggested that extracellular xylose was sensed by the glucose sensors Rgt2p and Snf3p. Proteome analyses revealed distinct patterns in phosphorylation of hexokinase 2, glucokinase and enolase isoenzymes in the xylose- and glucose-grown cells. Conclusion The results indicate that the metabolism of yeast growing on xylose corresponds neither to that of fully glucose repressed cells nor that of derepressed cells. This may be one of the major reasons for the suboptimal fermentation of xylose by recombinant S. cerevisiae strains. Phosphorylation of different isoforms of glycolytic enzymes suggests that regulation of glycolysis also occurred at a post-translational level, supporting prior findings. PMID:18533012

Salusjarvi, Laura; Kankainen, Matti; Soliymani, Rabah; Pitkanen, Juha-Pekka; Penttila, Merja; Ruohonen, Laura

2008-01-01

189

Starmerella bombicola influences the metabolism of Saccharomyces cerevisiae at pyruvate decarboxylase and alcohol dehydrogenase level during mixed wine fermentation  

PubMed Central

Background The use of a multistarter fermentation process with Saccharomyces cerevisiae and non-Saccharomyces wine yeasts has been proposed to simulate natural must fermentation and to confer greater complexity and specificity to wine. In this context, the combined use of S. cerevisiae and immobilized Starmerella bombicola cells (formerly Candida stellata) was assayed to enhance glycerol concentration, reduce ethanol content and to improve the analytical composition of wine. In order to investigate yeast metabolic interaction during controlled mixed fermentation and to evaluate the influence of S. bombicola on S. cerevisiae, the gene expression and enzymatic activity of two key enzymes of the alcoholic fermentation pathway such as pyruvate decarboxylase (Pdc1) and alcohol dehydrogenase (Adh1) were studied. Results The presence of S. bombicola immobilized cells in a mixed fermentation trial confirmed an increase in fermentation rate, a combined consumption of glucose and fructose, an increase in glycerol and a reduction in the production of ethanol as well as a modification in the fermentation of by products. The alcoholic fermentation of S. cerevisiae was also influenced by S. bombicola immobilized cells. Indeed, Pdc1 activity in mixed fermentation was lower than that exhibited in pure culture while Adh1 activity showed an opposite behavior. The expression of both PDC1 and ADH1 genes was highly induced at the initial phase of fermentation. The expression level of PDC1 at the end of fermentation was much higher in pure culture while ADH1 level was similar in both pure and mixed fermentations. Conclusion In mixed fermentation, S. bombicola immobilized cells greatly affected the fermentation behavior of S. cerevisiae and the analytical composition of wine. The influence of S. bombicola on S. cerevisiae was not limited to a simple additive contribution. Indeed, its presence caused metabolic modifications during S. cerevisiae fermentation causing variation in the gene expression and enzymatic activity of alcohol deydrogenase and pyruvate decarboxilase. PMID:22305374

2012-01-01

190

Analysis of Meiotic Recombination Pathways in the Yeast Saccharomyces Cerevisiae  

PubMed Central

In the yeast, Saccharomyces cerevisiae, several genes appear to act early in meiotic recombination. HOP1 and RED1 have been classified as such early genes. The data in this paper demonstrate that neither a red1 nor a hop1 mutation can rescue the inviable spores produced by a rad52 spo13 strain; this phenotype helps to distinguish these two genes from other early meiotic recombination genes such as SPO11, REC104, or MEI4. In contrast, either a red1 or a hop1 mutation can rescue a rad50S spo13 strain; this phenotype is similar to that conferred by mutations in the other early recombination genes (e.g., REC104). These two different results can be explained because the data presented here indicate that a rad50S mutation does not diminish meiotic intrachromosomal recombination, similar to the mutant phenotypes conferred by red1 or hop1. Of course, RED1 and HOP1 do act in the normal meiotic interchromosomal recombination pathway; they reduce interchromosomal recombination to ~10% of normal levels. We demonstrate that a mutation in a gene (REC104) required for initiation of exchange is completely epistatic to a mutation in RED1. Finally, mutations in either HOP1 or RED1 reduce the number of double-strand breaks observed at the HIS2 meiotic recombination hotspot. PMID:8878674

Mao-Draayer, Y.; Galbraith, A. M.; Pittman, D. L.; Cool, M.; Malone, R. E.

1996-01-01

191

Effect of Polygodial on the Mitochondrial ATPase of Saccharomyces cerevisiae  

PubMed Central

The fungicidal mechanism of a naturally occurring sesquiterpene dialdehyde, polygodial, was investigated in Saccharomyces cerevisiae. In an acidification assay, polygodial completely suppressed the glucose-induced decrease in external pH at 3.13 ?g/ml, the same as the fungicidal concentration. Acidification occurs primarily through the proton-pumping action of the plasma membrane ATPase, Pma1p. Surprisingly, this ATPase was not directly inhibited by polygodial. In contrast, the two other membrane-bound ATPases in yeast were found to be susceptible to the compound. The mitochondrial ATPase was inhibited by polygodial in a dose-dependent manner at concentrations similar to the fungicidal concentration, whereas the vacuolar ATPase was only slightly inhibited. Cytoplasmic petite mutants, which lack mitochondrial DNA and are respiration deficient, were significantly less susceptible to polygodial than the wild type, as was shown in time-kill curves. A pet9 mutant which lacks a functional ADP-ATP translocator and is therefore respiration dependent was rapidly inhibited by polygodial. The results of these susceptibility assays link enzyme inhibition to physiological effect. Previous studies have reported that plasma membrane disruption is the mechanism of polygodial-induced cell death; however, these results support a more complex picture of its effect. A major target of polygodial in yeast is mitochondrial ATP synthase. Reduction of the ATP supply leads to a suppression of Pma1 ATPase activity and impairs adaptive responses to other facets of polygodial's cellular inhibition. PMID:10858359

Lunde, Christopher S.; Kubo, Isao

2000-01-01

192

MAP Kinase Pathways in the Yeast Saccharomyces cerevisiae  

PubMed Central

A cascade of three protein kinases known as a mitogen-activated protein kinase (MAPK) cascade is commonly found as part of the signaling pathways in eukaryotic cells. Almost two decades of genetic and biochemical experimentation plus the recently completed DNA sequence of the Saccharomyces cerevisiae genome have revealed just five functionally distinct MAPK cascades in this yeast. Sexual conjugation, cell growth, and adaptation to stress, for example, all require MAPK-mediated cellular responses. A primary function of these cascades appears to be the regulation of gene expression in response to extracellular signals or as part of specific developmental processes. In addition, the MAPK cascades often appear to regulate the cell cycle and vice versa. Despite the success of the gene hunter era in revealing these pathways, there are still many significant gaps in our knowledge of the molecular mechanisms for activation of these cascades and how the cascades regulate cell function. For example, comparison of different yeast signaling pathways reveals a surprising variety of different types of upstream signaling proteins that function to activate a MAPK cascade, yet how the upstream proteins actually activate the cascade remains unclear. We also know that the yeast MAPK pathways regulate each other and interact with other signaling pathways to produce a coordinated pattern of gene expression, but the molecular mechanisms of this cross talk are poorly understood. This review is therefore an attempt to present the current knowledge of MAPK pathways in yeast and some directions for future research in this area. PMID:9841672

Gustin, Michael C.; Albertyn, Jacobus; Alexander, Matthew; Davenport, Kenneth

1998-01-01

193

Coexpression of ?-l-arabinofuranosidase and ?-glucosidase in Saccharomyces cerevisiae.  

PubMed

Monoterpenes are important aroma compounds in grape varieties such as Muscat, Gewürztraminer and Riesling, and are present as either odourless, glycosidically bound complexes or free aromatic monoterpenes. Commercial enzymes can be used to release the monoterpenes, but they commonly consist of crude extracts that often have unwanted and unpredictable side-effects on wine aroma. This project aims to address these problems by the expression and secretion of the Aspergillus awamori?-l-arabinofuranosidase in combination with either the ?-glucosidases from Saccharomycopsis fibuligera or from Aspergillus kawachii in the industrial yeast Saccharomyces cerevisiae VIN13. The concentration of five monoterpenes was monitored throughout alcoholic fermentation of Gewürztraminer grapes. The recombinant yeast strains that caused an early boost in the geraniol concentration led to a reduction in the final geraniol levels due to the downregulation of the sterol biosynthetic pathway. Monoterpene concentrations were also analysed 9 and 38 days after racking and the performance of the VB2 and VAB2 recombinant strains was similar, and in many cases, better than that of a commercial enzyme used in the same experiment. The results were backed by sensorial analysis, with the panel preferring the aroma of the wines produced by the VAB2 strain. PMID:21062416

Zietsman, Anscha J J; de Klerk, Daniel; van Rensburg, Pierre

2011-02-01

194

Pathway correcting DNA replication errors in Saccharomyces cerevisiae.  

PubMed Central

Mutation of predicted 3'-->5' exonuclease active site residues of Saccharomyces cerevisiae POL3 DNA polymerase (delta) or deletion of the PMS1 mismatch repair gene lead to relative (to wild type) spontaneous mutation rates of approximately 130 and 41, respectively, measured at a URA3 reporter gene inserted near to a defined replication origin. The POL3 exonuclease-deficient mutant pol3-01 generated most classes of single base mutation in URA3, indicating a broad specificity that generally corresponds to that of the PMS1 system. pol3-01 pms1 haploid cells ceased growth after a few divisions with no unique terminal cell morphology. A pol3-01/pol3-01 pms1/pms1 diploid was viable and displayed an estimated URA3 relative mutation rate of 2 x 10(4), which we calculate to be catastrophically high in a haploid. The relationship between the relative mutation rates of pol3-01 and pms1 was multiplicative, indicating action in series. The PMS1 transcript showed the same cell cycle periodicity as those of a set of DNA replication genes that includes POL3, suggesting PMS1 is co-regulated with these genes. We propose that the POL3 3'-->5' exonuclease and the PMS1 mismatch repair system act on a common pathway analogous to the dnaQ-->mutHLS pathway of DNA replication error correction in Escherichia coli. Images PMID:8385605

Morrison, A; Johnson, A L; Johnston, L H; Sugino, A

1993-01-01

195

Oxalurate induction of multiple URA3 transcripts in Saccharomyces cerevisiae.  

PubMed Central

The URA3 gene from Saccharomyces cerevisiae is localized on a 1.1-kilobase (kb) DNA fragment. By using this fragment as a hybridization probe, we found that oxalurate, a gratuitous inducer of the allantoin degradative system, also serves to induce URA3 specific RNA. This response is restricted to oxalurate; other conditions which bring about high-level synthesis of the allantoin degradative enzymes did not produce the effect. Two classes of RNA (1.0 and 1.5 kb) were found to be oxalurate induced. Both classes are encoded by the URA3 gene, overlap, and probably do not significantly differ at their 5' termini. Northern blot mapping of the transcripts indicated that the 1.5-kb transcript was likely encoded by sequences extending up to 0.5 kb downstream from the 3' terminus of the 1.0-kb transcript. Analysis of the endpoints of the major 1.0-kb URA3 transcript by S1 nuclease mapping revealed the existence of two 5' termini, separated by 5 to 10 nucleotides, and seven 3' termini, separated by 5 to 20 nucleotides each, over a range of about 70 bases. Images PMID:6140626

Buckholz, R G; Cooper, T G

1983-01-01

196

Fitness Effects of Ty Transposition in Saccharomyces Cerevisiae  

PubMed Central

It has been suggested that the primary evolutionary role of transposable elements is negative and parasitic. Alternatively, the target specificity and gene regulatory capabilities of many transposable elements raise the possibility that transposable element-induced mutations are more likely to be adaptively favorable than other types of mutations. Populations of Saccharomyces cerevisiae containing large amounts of variation for Ty1 genomic insertions were constructed, and the effects of Ty1 copy number on two components of fitness, yield and growth rate were determined. Although mean stationary phase density decreased with increased Ty1 copy number, the variance and range increased. The distributions of stationary phase densities indicate that many Ty1 insertions have negative effects on fitness, but also that some may have positive effects. To test directly for adaptively favorable Ty1 insertions, populations containing large amounts of variability for Ty1 copy number were grown in continuous culture. After 98-112 generations the frequency of clones containing zero Ty1 elements had decreased to ~0.0, and specific Ty1-containing clone families had predominated. Considering that most of the genetic variation in the populations was due to Ty1 transposition, and that Ty1 insertions had, on average, a negative effect on fitness, we conclude that Ty1 transposition events were directly responsible for the production of adaptive mutations in the clones that predominated in the populations. PMID:1317316

Wilke, C. M.; Adams, J.

1992-01-01

197

Global optimization of the Saccharomyces cerevisiae: fermentation process.  

PubMed

In this article, steady-state optimization of the Saccharomyces cerevisiae fermentation process problem is performed revealing the existence of multiple optimum solutions. The globally optimum solution was determined using the NEOS global optimization solver LINDO. A branch and bound strategy (bnb20.m) and the global search and multistart algorithms in the MATLAB global optimization toolbox were successful in determining locally optimum solutions and these results are validated by plotting the objective function against the decision variables. While in some cases all the strategies were successful in obtaining the globally optimum solutions, an example is presented where the most beneficial product value, which is not a stationary point and lies on the feasible boundary, is obtained by the LINDO global optimization solver (but not the other routines) as the globally optimum solution. The Jones-Kompala model was used to model the steady-state of the fermentation process. While several articles have been published demonstrating the existence of nonlinearities and bifurcations in this model, the challenges posed by this model to optimization has never been investigated so far and this work attempts to do so. Both dilution rate and the oxygen mass transfer coefficient were used as the decision variables individually and together. PMID:23780907

Sridhar, Lakshmi N

2013-01-01

198

Global optimization of the saccharomyces cerevisiae. Fermentation process.  

PubMed

In this paper steady-state optimization of the Saccharomyces cerevisiae fermentation process problem is performed revealing the existence of multiple optimum solutions. The globally optimum solution was determined using the NEOS global optimization solver LINDO. A branch and bound strategy (bnb20.m) and the global search and multistart algorithms in the MATLAB global optimization toolbox were successful in determining locally optimum solutions and these results are validated by plotting the objective function against the decision variables. While in some cases all the strategies were successful in obtaining the globally optimum solutions, an example is presented where the most beneficial product value, which is not a stationary point and lies on the feasible boundary, is obtained by the LINDO global optimization solver (but not the other routines) as the globally optimum solution. The Jones-Kompala model was used to model the steady-state of the fermentation process. While several articles have been published demonstrating the existence of nonlinearities and bifurcations in this model, the challenges posed by this model to optimization has never been investigated so far and this work attempts to do so. Both dilution rate and the oxygen mass transfer coefficient were used as the decision variables individually and together. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 2013. PMID:23737357

Sridhar, Lakshmi N

2013-06-01

199

Assembly of evolved ligninolytic genes in Saccharomyces cerevisiae.  

PubMed

The ligninolytic enzymatic consortium produced by white-rot fungi is one of the most efficient oxidative systems found in nature, with many potential applications that range from the production of 2nd generation biofuels to chemicals synthesis. In the current study, two high redox potential oxidoreductase fusion genes (laccase -Lac- and versatile peroxidase -Vp-) that had been evolved in the laboratory were re-assembled in Saccharomyces cerevisiae. First, cell viability and secretion were assessed after co-transforming the Lac and Vp genes into yeast. Several expression cassettes were inserted in vivo into episomal bi-directional vectors in order to evaluate inducible promoter and/or terminator pairs of different strengths in an individual and combined manner. The synthetic white-rot yeast model harboring Vp(GAL1/CYC1)-Lac(GAL10/ADH1) displayed up to 1000 and 100 Units per L of peroxidase and laccase activity, respectively, representing a suitable point of departure for future synthetic biology studies. PMID:24830983

Gonzalez-Perez, David; Alcalde, Miguel

2014-01-01

200

Transcriptional regulatory network shapes the genome structure of Saccharomyces cerevisiae.  

PubMed

Among cellular processes gene transcription is central. More and more evidence is mounting that transcription is tightly connected with the spatial organization of the chromosomes. Spatial proximity of genes sharing transcriptional machinery is one of the consequences of this organization. Motivated by information on the physical relationship among genes identified via chromosomal conformation capture methods, we complement the spatial organization with the idea that genes under similar transcription factor control, but possible scattered throughout the genome, might be in physically proximity to facilitate the access of their commonly used transcription factors. Unlike the transcription factory model, "interacting" genes in our "Gene Proximity Model" are not necessarily immediate physical neighbors but are in spatial proximity. Considering the stochastic nature of TF-promoter binding, this local condensation mechanism could serve as a tie to recruit co-regulated genes to guarantee the swiftness of biological reactions. We tested this idea with a simple eukaryotic organism, Saccharomyces cerevisiae. Chromosomal interaction patterns and folding behavior generated by our model re-construct those obtained from experiments. We show that the transcriptional regulatory network has a close linkage with the genome organization in budding yeast, which is fundamental and instrumental to later studies on other more complex eukaryotes. PMID:23674068

Li, Songling; Heermann, Dieter W

2013-01-01

201

Scanning electron microscope study of Saccharomyces cerevisiae spheroplast formation.  

PubMed Central

A suspension of Saccharomyces cerevisiae NCY366 in buffered 1.2 M sorbitol containing Zymolyase-5000 (a beta-glucanase-containing preparation/showed maximum osmotic sensitivity after 30 min of incubation at 30 degrees C. A scanning electron microscope study of spheroplast formation, using a very high resolution (4-nm) machine, revealed several new morphological features. The surface of the plug in bud scars on intact cells appeared warty. The wall, which assumed a beady appearance as digestion proceded, ultimately sloughed off to reveal the furrowed surface of the plasma membrane. Bud scars were resistant to digestion and. as incubation proceeded, they became surrounded by an outer annulus, which may be the seconary septum. Wall material was completely removed from the majority of cells only after 60 min of digestion. The surface of spheroplasts was studded with particles, about 25 to 30 nm in diameter. Many spheroplasts had a single large indentation, which may be in that part of the plasma membrane originally underlying the birth scar. Images PMID:387725

Pringle, A T; Forsdyke, J; Rose, A H

1979-01-01

202

Engineering chimeric thermostable GH7 cellobiohydrolases in Saccharomyces cerevisiae.  

PubMed

We report here the effect of adding different types of carbohydrate-binding modules (CBM) to a single-module GH7 family cellobiohydrolase Cel7A from a thermophilic fungus Talaromyces emersonii (TeCel7A). Both bacterial and fungal CBMs derived from families 1, 2 and 3, all reported to bind to crystalline cellulose, were used. Chimeric cellobiohydrolases with an additional S-S bridge in the catalytic module of TeCel7A were also made. All the fusion proteins were secreted in active form and in good yields by Saccharomyces cerevisiae. The purified chimeric enzymes bound to cellulose clearly better than the catalytic module alone and demonstrated high thermal stability, having unfolding temperatures (T m) ranging from 72 °C to 77 °C. The highest activity enhancement on microcrystalline cellulose could be gained by a fusion with a bacterial CBM3 derived from Clostridium thermocellum cellulosomal-scaffolding protein CipA. The two CBM3 fusion enzymes tested were more active than the reference enzyme Trichoderma reesei Cel7A both at moderate (45 °C and 55 °C) and at high temperatures (60 °C and 65 °C), the hydrolysis yields being two- to three-fold better at 60 °C, and six- to seven-fold better at 65 °C. The best enzyme variant was also tested on a lignocellulosic feedstock hydrolysis, which demonstrated its potency in biomass hydrolysis even at 70 °C. PMID:23974371

Voutilainen, Sanni P; Nurmi-Rantala, Susanna; Penttilä, Merja; Koivula, Anu

2014-04-01

203

Architecture and Biosynthesis of the Saccharomyces cerevisiae Cell Wall  

PubMed Central

The wall gives a Saccharomyces cerevisiae cell its osmotic integrity; defines cell shape during budding growth, mating, sporulation, and pseudohypha formation; and presents adhesive glycoproteins to other yeast cells. The wall consists of ?1,3- and ?1,6-glucans, a small amount of chitin, and many different proteins that may bear N- and O-linked glycans and a glycolipid anchor. These components become cross-linked in various ways to form higher-order complexes. Wall composition and degree of cross-linking vary during growth and development and change in response to cell wall stress. This article reviews wall biogenesis in vegetative cells, covering the structure of wall components and how they are cross-linked; the biosynthesis of N- and O-linked glycans, glycosylphosphatidylinositol membrane anchors, ?1,3- and ?1,6-linked glucans, and chitin; the reactions that cross-link wall components; and the possible functions of enzymatic and nonenzymatic cell wall proteins. PMID:23135325

Orlean, Peter

2012-01-01

204

TOR and RAS pathways regulate desiccation tolerance in Saccharomyces cerevisiae  

PubMed Central

Tolerance to desiccation in cultures of Saccharomyces cerevisiae is inducible; only one in a million cells from an exponential culture survive desiccation compared with one in five cells in stationary phase. Here we exploit the desiccation sensitivity of exponentially dividing cells to understand the stresses imposed by desiccation and their stress response pathways. We found that induction of desiccation tolerance is cell autonomous and that there is an inverse correlation between desiccation tolerance and growth rate in glucose-, ammonia-, or phosphate-limited continuous cultures. A transient heat shock induces a 5000–fold increase in desiccation tolerance, whereas hyper-ionic, -reductive, -oxidative, or -osmotic stress induced much less. Furthermore, we provide evidence that the Sch9p-regulated branch of the TOR and Ras-cAMP pathway inhibits desiccation tolerance by inhibiting the stress response transcription factors Gis1p, Msn2p, and Msn4p and by activating Sfp1p, a ribosome biogenesis transcription factor. Among 41 mutants defective in ribosome biogenesis, a subset defective in 60S showed a dramatic increase in desiccation tolerance independent of growth rate. We suggest that reduction of a specific intermediate in 60S biogenesis, resulting from conditions such as heat shock and nutrient deprivation, increases desiccation tolerance. PMID:23171550

Welch, Aaron Z.; Gibney, Patrick A.; Botstein, David; Koshland, Douglas E.

2013-01-01

205

Characterization of Saccharomyces cerevisiae mutants supersensitive to aminoglycoside antibiotics.  

PubMed Central

We describe mutants of Saccharomyces cerevisiae that are more sensitive than the wild type to the aminoglycoside antibiotics G418, hygromycin B, destomycin A, and gentamicin X2. In addition, the mutants are sensitive to apramycin, kanamycin B, lividomycin A, neamine, neomycin, paromomycin, and tobramycin--antibiotics which do not inhibit wild-type strains. Mapping studies suggest that supersensitivity is caused by mutations in at least three genes, denoted AGS1, AGS2, and AGS3 (for aminoglycoside antibiotic sensitivity). Mutations in all three genes are required for highest antibiotic sensitivity; ags1 ags2 double mutants have intermediate antibiotic sensitivity. AGS1 was mapped 8 centimorgans distal from LEU2 on chromosome III. Analyses of yeast strains transformed with vectors carrying antibiotic resistance genes revealed that G418, gentamicin X2, kanamycin B, lividomycin A, neamine, and paromomycin are inactivated by the Tn903 phosphotransferase and that destomycin A is inactivated by the hygromycin B phosphotransferase. ags strains are improved host strains for vectors carrying the phosphotransferase genes because a wide spectrum of aminoglycoside antibiotics can be used to select for plasmid maintenance. PMID:2989254

Ernst, J F; Chan, R K

1985-01-01

206

Transcriptional Response of Saccharomyces cerevisiae to Desiccation and Rehydration†  

PubMed Central

A transcriptional analysis of the response of Saccharomyces cerevisiae strain BY4743 to controlled air-drying (desiccation) and subsequent rehydration under minimal glucose conditions was performed. Expression of genes involved in fatty acid oxidation and the glyoxylate cycle was observed to increase during drying and remained in this state during the rehydration phase. When the BY4743 expression profile for the dried sample was compared to that of a commercially prepared dry active yeast, strikingly similar expression changes were observed. The fact that these two samples, dried by different means, possessed very similar transcriptional profiles supports the hypothesis that the response to desiccation is a coordinated event independent of the particular conditions involved in water removal. Similarities between “stationary-phase-essential genes” and those upregulated during desiccation were also noted, suggesting commonalities in different routes to reduced metabolic states. Trends in extracellular and intracellular glucose and trehalose levels suggested that the cells were in a “holding pattern” during the rehydration phase, a concept that was reinforced by cell cycle analyses. Application of a “redescription mining” algorithm suggested that sulfur metabolism is important for cell survival during desiccation and rehydration. PMID:16332871

Singh, Jatinder; Kumar, Deept; Ramakrishnan, Naren; Singhal, Vibha; Jervis, Jody; Garst, James F.; Slaughter, Stephen M.; DeSantis, Andrea M.; Potts, Malcolm; Helm, Richard F.

2005-01-01

207

Genetic Analysis of Default Mating Behavior in Saccharomyces Cerevisiae  

PubMed Central

Haploid Saccharomyces cerevisiae cells find each other during conjugation by orienting their growth toward each other along pheromone gradients (chemotropism). However, when their receptors are saturated for pheromone binding, yeast cells must select a mate by executing a default pathway in which they choose a mating partner at random. We previously demonstrated that this default pathway requires the SPA2 gene. In this report we show that the default mating pathway also requires the AXL1, FUS1, FUS2, FUS3, PEA2, RVS161, and BNI1 genes. These genes, including SPA2, are also important for efficient cell fusion during chemotropic mating. Cells containing null mutations in these genes display defects in cell fusion that subtly affect mating efficiency. In addition, we found that the defect in default mating caused by mutations in SPA2 is partially suppressed by multiple copies of two genes, FUS2 and MFA2. These findings uncover a molecular relationship between default mating and cell fusion. Moreover, because axl1 mutants secrete reduced levels of a-factor and are defective at both cell fusion and default mating, these results reveal an important role for a-factor in cell fusion and default mating. We suggest that default mating places a more stringent requirement on some aspects of cell fusion than does chemotropic mating. PMID:9135999

Dorer, R.; Boone, C.; Kimbrough, T.; Kim, J.; Hartwell, L. H.

1997-01-01

208

Nutrient sensing and signaling in the yeast Saccharomyces cerevisiae  

PubMed Central

The yeast Saccharomyces cerevisiae has been a favorite organism for pioneering studies on nutrient-sensing and signaling mechanisms. Many specific nutrient responses have been elucidated in great detail. This has led to important new concepts and insight into nutrient-controlled cellular regulation. Major highlights include the central role of the Snf1 protein kinase in the glucose repression pathway, galactose induction, the discovery of a G-protein-coupled receptor system, and role of Ras in glucose-induced cAMP signaling, the role of the protein synthesis initiation machinery in general control of nitrogen metabolism, the cyclin-controlled protein kinase Pho85 in phosphate regulation, nitrogen catabolite repression and the nitrogen-sensing target of rapamycin pathway, and the discovery of transporter-like proteins acting as nutrient sensors. In addition, a number of cellular targets, like carbohydrate stores, stress tolerance, and ribosomal gene expression, are controlled by the presence of multiple nutrients. The protein kinase A signaling pathway plays a major role in this general nutrient response. It has led to the discovery of nutrient transceptors (transporter receptors) as nutrient sensors. Major shortcomings in our knowledge are the relationship between rapid and steady-state nutrient signaling, the role of metabolic intermediates in intracellular nutrient sensing, and the identity of the nutrient sensors controlling cellular growth. PMID:24483210

Conrad, Michaela; Schothorst, Joep; Kankipati, Harish Nag; Van Zeebroeck, Griet; Rubio-Texeira, Marta; Thevelein, Johan M

2014-01-01

209

Multiple pathways for homologous recombination in Saccharomyces cerevisiae.  

PubMed

The genes in the RAD52 epistasis group of Saccharomyces cerevisiae are necessary for most mitotic and meiotic recombination events. Using an intrachromosomal inverted-repeat assay, we previously demonstrated that mitotic recombination of this substrate is dependent upon the RAD52 gene. In the present study the requirement for other genes in this epistasis group for recombination of inverted repeats has been analyzed, and double and triple mutant strains were examined for their epistatic relationships. The majority of recombination events are mediated by a RAD51-dependent pathway, where the RAD54, RAD55 and RAD57 genes function downstream of RAD51. Cells mutated in RAD55 or RAD57 as well as double mutants are cold-sensitive for inverted-repeat recombination, whereas a rad51 rad55 rad57 triple mutant is not. The RAD1 gene is not required for inverted-repeat recombination but is able to process spontaneous DNA lesions to produce recombinant products in the absence of RAD51. Furthermore, there is still considerably more recombination in rad1 rad51 mutants than in rad52 mutants, indicating the presence of another, as yet unidentified, recombination pathway. PMID:7705645

Rattray, A J; Symington, L S

1995-01-01

210

The Network Architecture of the Saccharomyces cerevisiae Genome  

PubMed Central

We propose a network-based approach for surmising the spatial organization of genomes from high-throughput interaction data. Our strategy is based on methods for inferring architectural features of networks. Specifically, we employ a community detection algorithm to partition networks of genomic interactions. These community partitions represent an intuitive interpretation of genomic organization from interaction data. Furthermore, they are able to recapitulate known aspects of the spatial organization of the Saccharomyces cerevisiae genome, such as the rosette conformation of the genome, the clustering of centromeres, as well as tRNAs, and telomeres. We also demonstrate that simple architectural features of genomic interaction networks, such as cliques, can give meaningful insight into the functional role of the spatial organization of the genome. We show that there is a correlation between inter-chromosomal clique size and replication timing, as well as cohesin enrichment. Together, our network-based approach represents an effective and intuitive framework for interpreting high-throughput genomic interaction data. Importantly, there is a great potential for this strategy, given the rich literature and extensive set of existing tools in the field of network analysis. PMID:24349163

Hoang, Stephen A.; Bekiranov, Stefan

2013-01-01

211

Regulation of the Saccharomyces cerevisiae DNA repair gene RAD16.  

PubMed Central

The RAD16 gene product has been shown to be essential for the repair of the silenced mating type loci [Bang et al. (1992) Nucleic Acids Res. 20, 3925-3931]. More recently we demonstrated that the RAD16 and RAD7 proteins are also required for repair of non-transcribed strands of active genes in Saccharomyces cerevisiae [Waters et al. (1993) Mol. Gen. Genet. 239, 28-32]. We have studied the regulation of the RAD16 gene and found that the RAD16 transcript levels increased up to 7-fold upon UV irradiation. Heat shock at 42 degrees C also results in elevated levels of RAD16 mRNA. In sporulating MAT alpha/MATa diploid cells RAD16 mRNA is also induced. The basal level of the RAD16 transcript is constant during the mitotic cell cycle. G1-arrested cells show normal induction of RAD16 mRNA upon UV irradiation demonstrating that the induction is not a secondary consequence of G2 cell cycle arrest following UV irradiation. However, in cells arrested in G1 the induction of RAD16 mRNA after UV irradiation is not followed by a rapid decline as occurs in normal growing cells suggesting that the down regulation of RAD16 transcription is dependent on progression into the cell cycle. Images PMID:7784171

Bang, D D; Timmermans, V; Verhage, R; Zeeman, A M; van de Putte, P; Brouwer, J

1995-01-01

212

Comparative Genomics of Saccharomyces cerevisiae Natural Isolates for Bioenergy Production.  

PubMed

Lignocellulosic plant material is a viable source of biomass to produce alternative energy including ethanol and other biofuels. However, several factors-including toxic byproducts from biomass pretreatment and poor fermentation of xylose and other pentose sugars-currently limit the efficiency of microbial biofuel production. To begin to understand the genetic basis of desirable traits, we characterized three strains of Saccharomyces cerevisiae with robust growth in a pretreated lignocellulosic hydrolysate or tolerance to stress conditions relevant to industrial biofuel production, through genome and transcriptome sequencing analysis. All stress resistant strains were highly mosaic, suggesting that genetic admixture may contribute to novel allele combinations underlying these phenotypes. Strain-specific gene sets not found in the lab strain were functionally linked to the tolerances of particular strains. Furthermore, genes with signatures of evolutionary selection were enriched for functional categories important for stress resistance and included stress-responsive signaling factors. Comparison of the strains' transcriptomic responses to heat and ethanol treatment-two stresses relevant to industrial bioethanol production-pointed to physiological processes that were related to particular stress resistance profiles. Many of the genotype-by-environment expression responses occurred at targets of transcription factors with signatures of positive selection, suggesting that these strains have undergone positive selection for stress tolerance. Our results generate new insights into potential mechanisms of tolerance to stresses relevant to biofuel production, including ethanol and heat, present a backdrop for further engineering, and provide glimpses into the natural variation of stress tolerance in wild yeast strains. PMID:25193303

Wohlbach, Dana J; Rovinskiy, Nikolay; Lewis, Jeffrey A; Sardi, Maria; Schackwitz, Wendy S; Martin, Joel A; Deshpande, Shweta; Daum, Christopher G; Lipzen, Anna; Sato, Trey K; Gasch, Audrey P

2014-01-01

213

Dual effects of plant steroidal alkaloids on Saccharomyces cerevisiae.  

PubMed

Many plant species accumulate sterols and triterpenes as antimicrobial glycosides. These secondary metabolites (saponins) provide built-in chemical protection against pest and pathogen attack and can also influence induced defense responses. In addition, they have a variety of important pharmacological properties, including anticancer activity. The biological mechanisms underpinning the varied and diverse effects of saponins on microbes, plants, and animals are only poorly understood despite the ecological and pharmaceutical importance of this major class of plant secondary metabolites. Here we have exploited budding yeast (Saccharomyces cerevisiae) to investigate the effects of saponins on eukaryotic cells. The tomato steroidal glycoalkaloid alpha-tomatine has antifungal activity towards yeast, and this activity is associated with membrane permeabilization. Removal of a single sugar from the tetrasaccharide chain of alpha-tomatine results in a substantial reduction in antimicrobial activity. Surprisingly, the complete loss of sugars leads to enhanced antifungal activity. Experiments with alpha-tomatine and its aglycone tomatidine indicate that the mode of action of tomatidine towards yeast is distinct from that of alpha-tomatine and does not involve membrane permeabilization. Investigation of the effects of tomatidine on yeast by gene expression and sterol analysis indicate that tomatidine inhibits ergosterol biosynthesis. Tomatidine-treated cells accumulate zymosterol rather than ergosterol, which is consistent with inhibition of the sterol C(24) methyltransferase Erg6p. However, erg6 and erg3 mutants (but not erg2 mutants) have enhanced resistance to tomatidine, suggesting a complex interaction of erg mutations, sterol content, and tomatidine resistance. PMID:16870766

Simons, Veronika; Morrissey, John P; Latijnhouwers, Maita; Csukai, Michael; Cleaver, Adam; Yarrow, Carol; Osbourn, Anne

2006-08-01

214

Comparative Genomics of Saccharomyces cerevisiae Natural Isolates for Bioenergy Production  

PubMed Central

Lignocellulosic plant material is a viable source of biomass to produce alternative energy including ethanol and other biofuels. However, several factors—including toxic byproducts from biomass pretreatment and poor fermentation of xylose and other pentose sugars—currently limit the efficiency of microbial biofuel production. To begin to understand the genetic basis of desirable traits, we characterized three strains of Saccharomyces cerevisiae with robust growth in a pretreated lignocellulosic hydrolysate or tolerance to stress conditions relevant to industrial biofuel production, through genome and transcriptome sequencing analysis. All stress resistant strains were highly mosaic, suggesting that genetic admixture may contribute to novel allele combinations underlying these phenotypes. Strain-specific gene sets not found in the lab strain were functionally linked to the tolerances of particular strains. Furthermore, genes with signatures of evolutionary selection were enriched for functional categories important for stress resistance and included stress-responsive signaling factors. Comparison of the strains’ transcriptomic responses to heat and ethanol treatment—two stresses relevant to industrial bioethanol production—pointed to physiological processes that were related to particular stress resistance profiles. Many of the genotype-by-environment expression responses occurred at targets of transcription factors with signatures of positive selection, suggesting that these strains have undergone positive selection for stress tolerance. Our results generate new insights into potential mechanisms of tolerance to stresses relevant to biofuel production, including ethanol and heat, present a backdrop for further engineering, and provide glimpses into the natural variation of stress tolerance in wild yeast strains. PMID:25193303

Wohlbach, Dana J.; Rovinskiy, Nikolay; Lewis, Jeffrey A.; Sardi, Maria; Schackwitz, Wendy S.; Martin, Joel A.; Deshpande, Shweta; Daum, Christopher G.; Lipzen, Anna; Sato, Trey K.; Gasch, Audrey P.

2014-01-01

215

Tor1 regulates protein solubility in Saccharomyces cerevisiae  

PubMed Central

Accumulation of insoluble protein in cells is associated with aging and aging-related diseases; however, the roles of insoluble protein in these processes are uncertain. The nature and impact of changes to protein solubility during normal aging are less well understood. Using quantitative mass spectrometry, we identify 480 proteins that become insoluble during postmitotic aging in Saccharomyces cerevisiae and show that this ensemble of insoluble proteins is similar to those that accumulate in aging nematodes. SDS-insoluble protein is present exclusively in a nonquiescent subpopulation of postmitotic cells, indicating an asymmetrical distribution of this protein. In addition, we show that nitrogen starvation of young cells is sufficient to cause accumulation of a similar group of insoluble proteins. Although many of the insoluble proteins identified are known to be autophagic substrates, induction of macroautophagy is not required for insoluble protein formation. However, genetic or chemical inhibition of the Tor1 kinase is sufficient to promote accumulation of insoluble protein. We conclude that target of rapamycin complex 1 regulates accumulation of insoluble proteins via mechanisms acting upstream of macroautophagy. Our data indicate that the accumulation of proteins in an SDS-insoluble state in postmitotic cells represents a novel autophagic cargo preparation process that is regulated by the Tor1 kinase. PMID:23097491

Peters, Theodore W.; Rardin, Matthew J.; Czerwieniec, Gregg; Evani, Uday S.; Reis-Rodrigues, Pedro; Lithgow, Gordon J.; Mooney, Sean D.; Gibson, Bradford W.; Hughes, Robert E.

2012-01-01

216

Mating-Type Genes and MAT Switching in Saccharomyces cerevisiae  

PubMed Central

Mating type in Saccharomyces cerevisiae is determined by two nonhomologous alleles, MATa and MAT?. These sequences encode regulators of the two different haploid mating types and of the diploids formed by their conjugation. Analysis of the MATa1, MAT?1, and MAT?2 alleles provided one of the earliest models of cell-type specification by transcriptional activators and repressors. Remarkably, homothallic yeast cells can switch their mating type as often as every generation by a highly choreographed, site-specific homologous recombination event that replaces one MAT allele with different DNA sequences encoding the opposite MAT allele. This replacement process involves the participation of two intact but unexpressed copies of mating-type information at the heterochromatic loci, HML? and HMRa, which are located at opposite ends of the same chromosome-encoding MAT. The study of MAT switching has yielded important insights into the control of cell lineage, the silencing of gene expression, the formation of heterochromatin, and the regulation of accessibility of the donor sequences. Real-time analysis of MAT switching has provided the most detailed description of the molecular events that occur during the homologous recombinational repair of a programmed double-strand chromosome break. PMID:22555442

Haber, James E.

2012-01-01

217

Genome engineering in Saccharomyces cerevisiae using CRISPR-Cas systems  

PubMed Central

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated (Cas) systems in bacteria and archaea use RNA-guided nuclease activity to provide adaptive immunity against invading foreign nucleic acids. Here, we report the use of type II bacterial CRISPR-Cas system in Saccharomyces cerevisiae for genome engineering. The CRISPR-Cas components, Cas9 gene and a designer genome targeting CRISPR guide RNA (gRNA), show robust and specific RNA-guided endonuclease activity at targeted endogenous genomic loci in yeast. Using constitutive Cas9 expression and a transient gRNA cassette, we show that targeted double-strand breaks can increase homologous recombination rates of single- and double-stranded oligonucleotide donors by 5-fold and 130-fold, respectively. In addition, co-transformation of a gRNA plasmid and a donor DNA in cells constitutively expressing Cas9 resulted in near 100% donor DNA recombination frequency. Our approach provides foundations for a simple and powerful genome engineering tool for site-specific mutagenesis and allelic replacement in yeast. PMID:23460208

DiCarlo, James E.; Norville, Julie E.; Mali, Prashant; Rios, Xavier; Aach, John; Church, George M.

2013-01-01

218

Recombinogenic activity of fresh cigarette smoke in Saccharomyces cerevisiae.  

PubMed

A procedure for determining the effect of fresh cigarette smoke on gene conversion in yeast. Saccharomyces cerevisiae D7, is described. Cigarette smoke, generated by a 2-sec, 40-ml puff, once per minute, was puffed into an open-end tube. The smoke was drawn through an exposure vessel containing a continuously stirred, stationary-phase yeast cell suspension, 1-58 sec after generation. Frequency of gene conversion was estimated in samples taken at intervals after the start of exposure. Under these conditions, a five-fold increase in mitotic gene conversion in yeast strain D7 was obtained from exposure to 20 puffs of fresh whole smoke from University of Kentucky Reference Cigarettes (2R1), to 75 puffs from the gas phase of these cigarettes, and to 45 puffs from an acetate filter version (2R1F). Selective removal of genetically active components by acetate filters is suggested since the reduction in recombinogenic activity (55%) is greater than the reduction in total particulate matter yield (25%) of the cigarette. The results indicate that 1) the procedure provides a practical bioassay for determining the effects of fresh smoke on gene conversion in yeast, without external metabolic activation; 2) the gas phase of smoke has recombinogenic activity; and 3) standard acetate filters may selectively remove genetically active components of cigarette smoke. PMID:6762250

Gairola, C C; Griffith, R B

1981-01-01

219

Structural and Functional Analysis of Saccharomyces Cerevisiae Mob1  

SciTech Connect

The Mob proteins function as activator subunits for the Dbf2/Dbf20 family of protein kinases. Human and Xenopus Mob1 protein structures corresponding to the most conserved C-terminal core, but lacking the variable N-terminal region, have been reported and provide a framework for understanding the mechanism of Dbf2/Dbf20 regulation. Here, we report the 2.0 {angstrom} X-ray crystal structure of Saccharomyces cerevisiae Mob1 containing both the conserved C-terminal core and the variable N-terminal region. Within the N-terminal region, three novel structural elements are observed; namely, an {alpha}-helix denoted H0, a strand-like element denoted S0 and a short {beta} strand denoted S-1. Helix H0 associates in an intermolecular manner with a second Mob1 molecule to form a Mob1 homodimer. Strand S0 binds to the core domain in an intramolecular manner across a putative Dbf2 binding site mapped by Mob1 temperature-sensitive alleles and NMR binding experiments. In vivo functional analysis demonstrates that Mob1 mutants that target helix H0 or its reciprocal binding site are biologically compromised. The N-terminal region of Mob1 thus contains structural elements that are functionally important.

Mrkobrada,S.; Boucher, L.; Tyers, D.; Sicheri, F.

2006-01-01

220

Polyphosphates as an energy source for growth of Saccharomyces cerevisiae.  

PubMed

Cells of the yeast Saccharomyces cerevisiae with a low content of polyphosphates (polyP) are characterized by disturbance of growth in medium with 0.5% glucose. The parent strain with polyP level reduced by phosphate starvation had a longer lag phase. The growth rate of strains with genetically determined low content of polyP due to their enhanced hydrolysis (CRN/pMB1_PPN1 Sc is a superproducer of exopolyphosphatase PPN1) or reduced synthesis (the BY4741 vma2? mutant with impaired vacuolar membrane energization) was lower in the exponential phase. The growth of cells with high content of polyP was accompanied by polyP consumption. In cells of strains with low content of polyP, CRN/pMB1_PPN1 Sc and BY4741 vma2?, their consumption was insignificant. These findings provide more evidence indicating the use of polyP as an extra energy source for maintaining high growth rate. PMID:24954599

Trilisenko, L V; Kulakovskaya, T V

2014-05-01

221

Respiratory Development in Saccharomyces cerevisiae Grown at Controlled Oxygen Tension  

PubMed Central

Saccharomyces cerevisiae was grown in batch culture over a wide range of oxygen concentrations, varying from the anaerobic condition to a maximal dissolved oxygen concentration of 3.5 ?M. The development of cells was assayed by measuring amounts of the aerobic cytochromes aa3, b, c, and c1, the cellular content of unsaturated fatty acids and ergosterol, and the activity of respiratory enzyme complexes. The half-maximal levels of membrane-bound cytochromes aa3, b, and c1, were reached in cells grown in O2 concentrations around 0.1 ?M; this was similar to the oxygen concentration required for half-maximal levels of unsaturated fatty acid and sterol. However, the synthesis of ubiquinone and cytochrome c and the increase in fumarase activity were essentially linear functions of the dissolved oxygen concentration up to 3.5 ?M oxygen. The synthesis of the succinate dehydrogenase, succinate cytochrome c reductase, and cytochrome c oxidase complexes showed different responses to changes in O2 concentration in the growth medium. Cyanide-insensitive respiration and P450 cytochrome content were maximal at 0.25 ?M oxygen and declined in both more anaerobic and aerobic conditions. Cytochrome c peroxidase and catalase activities in cell-free homogenates were high in all but the most strictly anaerobic cells. PMID:4352179

Rogers, P. J.; Stewart, P. R.

1973-01-01

222

d-Xylulose Fermentation to Ethanol by Saccharomyces cerevisiae  

PubMed Central

We used commercial bakers' yeast (Saccharomyces cerevisiae) to study the conversion of d-xylulose to ethanol in the presence of d-xylose. The rate of ethanol production increased with an increase in yeast cell density. The optimal temperature for d-xylulose fermentation was 35°C, and the optimal pH range was 4 to 6. The fermentation of d-xylulose by yeast resulted in the production of ethanol as the major product; small amounts of xylitol and glycerol were also produced. The production of xylitol was influenced by pH as well as temperature. High pH values and low temperatures enhanced xylitol production. The rate of d-xylulose fermentation decreased when the production of ethanol yielded concentrations of 4% or more. The slow conversion rate of d-xylulose to ethanol was increased by increasing the yeast cell density. The overall production of ethanol from d-xylulose by yeast cells under optimal conditions was 90% of the theoretical yield. PMID:16345828

Chiang, Lin-Chang; Gong, Cheng-Shung; Chen, Li-Fu; Tsao, George T.

1981-01-01

223

The gcr (glycolysis regulation) mutation of Saccharomyces cerevisiae.  

PubMed

gcr is a mutation considerably decreasing the assayed amounts of most glycolysis enzymes in Saccharomyces cerevisiae (Clifton, D., Weinstock, S. B., and Fraenkel, D. G. (1978) Genetics 88, 1-11). We show here that although in the wild type strain the amounts of these enzymes do not greatly differ between cells from different media, in the gcr mutant strain most of the enzyme amounts are 5% or less, relative to wild type, from cells grown without sugars, but 20-50% from cells grown with sugars. Lower relative values were found for phosphoglycerate mutase and enolase. A corresponding alteration in the mutant in the intensities of several major protein bands could even be seen in stained gels after electrophoresis of crude extracts: the profiles were otherwise normal. Results of titration of phosphoglycerate kinase with antibody accorded with activity. Transfer of cells between the two types of media did not lead to a more rapid adjustment of enzyme amounts than expected from the steady state levels. gcr is not allelic to GPM (the gene for phosphoglycerate mutase) or to RNA1 (which affects transport of RNA from the nucleus). Translation of total RNA in a rabbit reticulocyte lysate gave a pattern of polypeptides similar to the in vivo one. Thus, gcr is likely to affect somehow mRNA synthesis or lifetime for a discrete number of proteins. PMID:7031056

Clifton, D; Fraenkel, D G

1981-12-25

224

Growth and metabolism of inositol-starved Saccharomyces cerevisiae.  

PubMed Central

Upon starvation for inositol, a phospholipid precursor, an inositol-requiring mutant of Saccharomyces cerevisiae has been shown to die if all other conditions are growth supporting. The growth and metabolism of inositol-starved cells has been investigated in order to determine the physiological state leading to "inositolless death". The synthesis of the major inositol-containing phospholipid ceases within 30 min after the removal of inositol from the growth medium. The cells, however, continue in an apparently normal fashion for one generation (2 h under the growth conditions used in this study). The cessation of cell division is not preceded or accompanied by any detectable change in the rate of macromolecular synthesis. When cell division ceases, the cells remain constant in volume, whereas macromolecular synthesis continues at first at an unchanged rate and eventually at a decreasing rate. Macromolecular synthesis terminates after about 4 h of inositol starvation, at approximately the time when the cells begin to die. Cell death is also accompanied by a decline in cellular potassium and adenosine triphosphate levels. The cells can be protected from inositolless death by several treatments that block cellular metabolism. It is concluded that inositol starvation results in a imbalance between the expansion of cell volume and the accumulation of cytoplasmic constituents. This imbalance is very likely the cause of inositolless death. Images PMID:323239

Henry, S A; Atkinson, K D; Kolat, A I; Culbertson, M R

1977-01-01

225

Transcriptional regulatory network shapes the genome structure of Saccharomyces cerevisiae  

PubMed Central

Among cellular processes gene transcription is central. More and more evidence is mounting that transcription is tightly connected with the spatial organization of the chromosomes. Spatial proximity of genes sharing transcriptional machinery is one of the consequences of this organization. Motivated by information on the physical relationship among genes identified via chromosomal conformation capture methods, we complement the spatial organization with the idea that genes under similar transcription factor control, but possible scattered throughout the genome, might be in physically proximity to facilitate the access of their commonly used transcription factors. Unlike the transcription factory model, “interacting” genes in our “Gene Proximity Model” are not necessarily immediate physical neighbors but are in spatial proximity. Considering the stochastic nature of TF-promoter binding, this local condensation mechanism could serve as a tie to recruit co-regulated genes to guarantee the swiftness of biological reactions. We tested this idea with a simple eukaryotic organism, Saccharomyces cerevisiae. Chromosomal interaction patterns and folding behavior generated by our model re-construct those obtained from experiments. We show that the transcriptional regulatory network has a close linkage with the genome organization in budding yeast, which is fundamental and instrumental to later studies on other more complex eukaryotes. PMID:23674068

Li, Songling; Heermann, Dieter W.

2013-01-01

226

Pre-Steady-State Analysis of ATP Hydrolysis by Saccharomyces cereVisiae DNA Topoisomerase II. 2. Kinetic Mechanism for the Sequential Hydrolysis of Two  

E-print Network

Pre-Steady-State Analysis of ATP Hydrolysis by Saccharomyces cereVisiae DNA Topoisomerase II. 2 ABSTRACT: In the preceding paper, we showed that DNA topoisomerase II from Saccharomyces cereVisiae binds orthovanadate, Sigma. The Saccharomyces cereVisiae to- poisomerase II and the sheared salmon sperm DNA were

Lewis, Timothy

227

University of Aberdeen PhD Studentship A novel stress signaling pathway in the yeast Saccharomyces cerevisiae  

E-print Network

. The related yeast Saccharomyces cerevisiae (baker's yeast) represents a very useful model for studyingUniversity of Aberdeen PhD Studentship A novel stress signaling pathway in the yeast Saccharomyces cerevisiae Supervisor; Dr Ian Stansfield, School of Medical Sciences Background Figure 1; Candida albicans

Swain, Peter

228

The acyl dihydroxyacetone phosphate pathway enzymes for glycerolipid biosynthesis are present in the yeast Saccharomyces cerevisiae.  

PubMed Central

The presence of the acyl dihydroxyacetone phosphate (acyl DHAP) pathway in yeasts was investigated by examining three key enzyme activities of this pathway in Saccharomyces cerevisiae. In the total membrane fraction of S. cerevisiae, we confirmed the presence of both DHAP acyltransferase (DHAPAT; Km = 1.27 mM; Vmax = 5.9 nmol/min/mg of protein) and sn-glycerol 3-phosphate acyltransferase (GPAT; Km = 0.28 mM; Vmax = 12.6 nmol/min/mg of protein). The properties of these two acyltransferases are similar with respect to thermal stability and optimum temperature of activity but differ with respect to pH optimum (6.5 for GPAT and 7.4 for DHAPAT) and sensitivity toward the sulfhydryl blocking agent N-ethylmaleimide. Total membrane fraction of S. cerevisiae also exhibited acyl/alkyl DHAP reductase (EC 1.1.1.101) activity, which has not been reported previously. The reductase has a Vmax of 3.8 nmol/min/mg of protein for the reduction of hexadecyl DHAP (Km = 15 microM) by NADPH (Km = 20 microM). Both acyl DHAP and alkyl DHAP acted as substrates. NADPH was the specific cofactor. Divalent cations and N-ethylmaleimide inhibited the enzymatic reaction. Reductase activity in the total membrane fraction from aerobically grown yeast cells was twice that from anaerobically grown cells. Similarly, DHAPAT and GPAT activities were also greater in aerobically grown yeast cells. The presence of these enzymes, together with the absence of both ether glycerolipids and the ether lipid-synthesizing enzyme (alkyl DHAP synthase) in S. cerevisiae, indicates that non-ether glycerolipids are synthesized in this organism via the acyl DHAP pathway. Images PMID:1512203

Racenis, P V; Lai, J L; Das, A K; Mullick, P C; Hajra, A K; Greenberg, M L

1992-01-01

229

Transporter engineering for improved tolerance against alkane biofuels in Saccharomyces cerevisiae  

PubMed Central

Background Hydrocarbon alkanes, components of major fossil fuels, are considered as next-generation biofuels because their biological production has recently been shown to be possible. However, high-yield alkane production requires robust host cells that are tolerant against alkanes, which exhibit cytotoxicity. In this study, we aimed to improve alkane tolerance in Saccharomyces cerevisiae, a key industrial microbial host, by harnessing heterologous transporters that potentially pump out alkanes. Results To this end, we attempted to exploit ABC transporters in Yarrowia lipolytica based on the observation that it utilizes alkanes as a carbon source. We confirmed the increased transcription of ABC2 and ABC3 transporters upon exposure to a range of alkanes in Y. lipolytica. We then showed that the heterologous expression of ABC2 and ABC3 transporters significantly increased tolerance against decane and undecane in S. cerevisiae through maintaining lower intracellular alkane level. In particular, ABC2 transporter increased the tolerance limit of S. cerevisiae about 80-fold against decane. Furthermore, through site-directed mutagenesis for glutamate (E988 for ABC2, and E989 for ABC3) and histidine (H1020 for ABC2, and H1021 for ABC3), we provided the evidence that glutamate was essential for the activity of ABC2 and ABC3 transporters, with ATP most likely to be hydrolyzed by a catalytic carboxylate mechanism. Conclusions Here, we demonstrated that transporter engineering through expression of heterologous efflux pumps led to significantly improved tolerance against alkane biofuels in S. cerevisiae. We believe that our results laid the groundwork for developing robust alkane-producing yeast cells through transporter engineering, which will greatly aid in next-generation alkane biofuel production and recovery. PMID:23402697

2013-01-01

230

Metabolic responses of pyruvate decarboxylase-negative Saccharomyces cerevisiae to glucose excess.  

PubMed Central

In Saccharomyces cerevisiae, oxidation of pyruvate to acetyl coenzyme A can occur via two routes. In pyruvate decarboxylase-negative (Pdc-) mutants, the pyruvate dehydrogenase complex is the sole functional link between glycolysis and the tricarboxylic acid (TCA) cycle. Such mutants therefore provide a useful experimental system with which to study regulation of the pyruvate dehydrogenase complex. In this study, a possible in vivo inactivation of the pyruvate dehydrogenase complex was investigated. When respiring, carbon-limited chemostat cultures of wild-type S. cerevisiae were pulsed with excess glucose, an immediate onset of respiro-fermentative metabolism occurred, accompanied by a strong increase of the glycolytic flux. When the same experiment was performed with an isogenic Pdc- mutant, only a small increase of the glycolytic flux was observed and pyruvate was the only major metabolite excreted. This finding supports the hypothesis that reoxidation of cytosolic NADH via pyruvate decarboxylase and alcohol dehydrogenase is a prerequisite for high glycolytic fluxes in S. cerevisiae. In Pdc- cultures, the specific rate of oxygen consumption increased by ca. 40% after a glucose pulse. Calculations showed that pyruvate excretion by the mutant was not due to a decrease of the pyruvate flux into the TCA cycle. We therefore conclude that rapid inactivation of the pyruvate dehydrogenase complex (e.g., by phosphorylation of its E1 alpha subunit, a mechanism demonstrated in many higher organisms) is not a relevant mechanism in the response of respiring S. cerevisiae cells to excess glucose. Consistently, pyruvate dehydrogenase activities in cell extracts did not exhibit a strong decrease after a glucose pulse. PMID:9292991

Flikweert, M T; van Dijken, J P; Pronk, J T

1997-01-01

231

Saccharomyces cerevisiae and non-Saccharomyces yeasts in grape varieties of the S?o Francisco Valley  

PubMed Central

The aims of this work was to characterise indigenous Saccharomyces cerevisiae strains in the naturally fermented juice of grape varieties Cabernet Sauvignon, Grenache, Tempranillo, Sauvignon Blanc and Verdejo used in the São Francisco River Valley, northeastern Brazil. In this study, 155 S. cerevisiae and 60 non-Saccharomyces yeasts were isolated and identified using physiological tests and sequencing of the D1/D2 domains of the large subunit of the rRNA gene. Among the non-Saccharomyces species, Rhodotorula mucilaginosa was the most common species, followed by Pichia kudriavzevii, Candida parapsilosis, Meyerozyma guilliermondii, Wickerhamomyces anomalus, Kloeckera apis, P. manshurica, C. orthopsilosis and C. zemplinina. The population counts of these yeasts ranged among 1.0 to 19 × 105 cfu/mL. A total of 155 isolates of S. cerevisiae were compared by mitochondrial DNA restriction analysis, and five molecular mitochondrial DNA restriction profiles were detected. Indigenous strains of S. cerevisiae isolated from grapes of the São Francisco Valley can be further tested as potential starters for wine production. PMID:25242923

de Ponzzes-Gomes, Camila M.P.B.S.; de Melo, Dangelly L.F.M.; Santana, Caroline A.; Pereira, Giuliano E.; Mendonca, Michelle O.C.; Gomes, Fatima C.O.; Oliveira, Evelyn S.; Barbosa, Antonio M.; Trindade, Rita C.; Rosa, Carlos A.

2014-01-01

232

Biogenesis of the Saccharomyces cerevisiae Mating Pheromone a-Factor  

PubMed Central

The Saccharomyces cerevisiae mating pheromone a-factor is a prenylated and carboxyl methylated extracellular peptide signaling molecule. Biogenesis of the a-factor precursor proceeds via a distinctive multistep pathway that involves COOH-terminal modification, NH2-terminal proteolysis, and a nonclassical export mechanism. In this study, we examine the formation and fate of a-factor biosynthetic intermediates to more precisely define the events that occur during a-factor biogenesis. We have identified four distinct a-factor biosynthetic intermediates (P0, P1, P2, and M) by metabolic labeling, immunoprecipitation, and SDSPAGE. We determined the biochemical composition of each by defining their NH2-terminal amino acid and COOH-terminal modification status. Unexpectedly, we discovered that not one, but two NH2-terminal cleavage steps occur during the biogenesis of a-factor. In addition, we have shown that COOH-terminal prenylation is required for the NH2-terminal processing of a-factor and that all the prenylated a-factor intermediates (P1, P2, and M) are membrane bound, suggesting that many steps of a-factor biogenesis occur in association with membranes. We also observed that although the biogenesis of a-factor is a rapid process, it is inherently inefficient, perhaps reflecting the potential for regulation. Previous studies have identified gene products that participate in the COOH-terminal modification (Ram1p, Ram2p, Ste14p), NH2-terminal processing (Ste24p, Axl1p), and export (Ste6p) of a-factor. The intermediates defined in the present study are discussed in the context of these biogenesis components to formulate an overall model for the pathway of a-factor biogenesis. PMID:9015298

Chen, Peng; Sapperstein, Stephanie K.; Choi, Jonathan D.; Michaelis, Susan

1997-01-01

233

Characterization of Glycogen-Deficient Glc Mutants of Saccharomyces Cerevisiae  

PubMed Central

Forty-eight mutants of Saccharomyces cerevisiae with defects in glycogen metabolism were isolated. The mutations defined eight GLC genes, the functions of which were determined. Mutations in three of these genes activate the RAS/cAMP pathway either by impairment of a RAS GTPase-activating protein (GLC1/IRA1 and GLC4/IRA2) or by activating Ras2p (GLC5/RAS2). SNF1 protein kinase (GLC2) was found to be required for normal glycogen levels. Glycogen branching enzyme (GLC3) was found to be required for significant glycogen synthesis. GLC6 was shown to be allelic to CIF1 (and probably FDP1, BYP1 and GGS1), mutations in which were previously found to prevent growth on glucose; this gene is also the same as TPS1, which encodes a subunit of the trehalose-phosphate synthase. Mutations in GLC6 were capable of increasing or decreasing glycogen levels, at least in part via effects on the regulation of glycogen synthase. GLC7 encodes a type 1 protein phosphatase that contributes to the dephosphorylation (and hence activation) of glycogen synthase. GLC8 encodes a homologue of type 1 protein phosphatase inhibitor-2. The genetic map positions of GLC1/IRA1, GLC3, GLC4/IRA2, GLC6/CIF1/TPS1 (and the adjacent VAT2/VMA2), and GLC7 were clarified. From the data on GLC3, there may be a suppression of recombination near the chromosome V centromere, at least in some strains. PMID:8150278

Cannon, J. F.; Pringle, J. R.; Fiechter, A.; Khalil, M.

1994-01-01

234

Metabolism and Regulation of Glycerolipids in the Yeast Saccharomyces cerevisiae  

PubMed Central

Due to its genetic tractability and increasing wealth of accessible data, the yeast Saccharomyces cerevisiae is a model system of choice for the study of the genetics, biochemistry, and cell biology of eukaryotic lipid metabolism. Glycerolipids (e.g., phospholipids and triacylglycerol) and their precursors are synthesized and metabolized by enzymes associated with the cytosol and membranous organelles, including endoplasmic reticulum, mitochondria, and lipid droplets. Genetic and biochemical analyses have revealed that glycerolipids play important roles in cell signaling, membrane trafficking, and anchoring of membrane proteins in addition to membrane structure. The expression of glycerolipid enzymes is controlled by a variety of conditions including growth stage and nutrient availability. Much of this regulation occurs at the transcriptional level and involves the Ino2–Ino4 activation complex and the Opi1 repressor, which interacts with Ino2 to attenuate transcriptional activation of UASINO-containing glycerolipid biosynthetic genes. Cellular levels of phosphatidic acid, precursor to all membrane phospholipids and the storage lipid triacylglycerol, regulates transcription of UASINO-containing genes by tethering Opi1 to the nuclear/endoplasmic reticulum membrane and controlling its translocation into the nucleus, a mechanism largely controlled by inositol availability. The transcriptional activator Zap1 controls the expression of some phospholipid synthesis genes in response to zinc availability. Regulatory mechanisms also include control of catalytic activity of glycerolipid enzymes by water-soluble precursors, products and lipids, and covalent modification of phosphorylation, while in vivo function of some enzymes is governed by their subcellular location. Genome-wide genetic analysis indicates coordinate regulation between glycerolipid metabolism and a broad spectrum of metabolic pathways. PMID:22345606

Henry, Susan A.; Kohlwein, Sepp D.; Carman, George M.

2012-01-01

235

Experimental bioenergetics of Saccharomyces cerevisiae in respiration and fermentation  

SciTech Connect

Aerobic growth of Saccharomyces cerevisiae on glucose was investigated, focusing on the heat evolution as it relates to biomass and EtOH synthesis. Aerobic fermentation and aerobic respiration were established respectively in the experimental system by performing batch and fed-batch experiments. Balanced growth batch cultivations were carried out with initial sugar concentrations of 10-70 g/L, resulting in different degrees of catabolite repression. The fermentative heat generation was continuously monitored in addition to the key culture parameters such as EtOH production rate, CO/sub 2/ evolution rate, O/sub 2/ uptake rate, sp. growth rate, and sugar consumption rate. The respective variations of the above quantities reflecting the variations in the catabolic activity of the culture were studied. This was done in order to evaluate the microbial regulatory system, the energetics of microbial growth including the rate of heat evolution, and the distribution of organic substrate between respiration and fermentation. This study was supported by closing C, energy, and electron balances on the system. The comparison of the fractions of substrate energy evolved as heat (delta h) with the fraction of available electrons transferred to O/sub 2/ (epsilon O/sub 2/) indicated equal values of the 2 (0.46) in the aerobic respiration (fed-batch cultivation). However, the glucose effect in batch cultivations resulted in smaller epsilon O/sub 2/ than delta h, while both values decreased in their absolute values. The evaluation of the heat energetic yield coefficient, together with the fraction of the available electrons transferred to O/sub 2/, contributed to the estimation of the extent of heat production through oxidative phosphorylation.

Yerushalmi, L.; Volesky, B.

1981-01-01

236

Experimental bioenergetics of Saccharomyces cerevisiae in respiration and fermentation  

SciTech Connect

Aerobic growth of Saccharomyces cerevisiae on glucose was investigated, focusing on the heat evolution as it relates to biomass and ethanol synthesis. ''Aerobic fermentation'' and ''aerobic respiration'' were established respectively in the experimental system by performing batch and fed-batch experiments. ''Balanced growth'' batch cultivations were carried out with initial sugar concentrations ranging from 10 to 70 g/L, resulting in different degrees of catabolite repression. The fermentative heat generation was continuously monitored in addition to the key culture parameters such as ethanol production rate, CO2 evolution rate, O2 uptake rate, specific growth rate, and sugar consumption rate. The respective variations of the above quantities reflecting the variations in the catabolic activity of the culture were studied. This was done in order to evaluate the microbial regulatory system, the energetics of microbial growth including the rate of heat evolution and the distribution of organic substrate between respiration and fermentation. This study was supported by closing c, energy, and electron balances on the system. The comparison of the fractions of substrate energy evolved as heat (delta h) with the fraction of available electrons transferred to oxygen (epsilon O2) indicated equal values of the two (0.46) in the aerobic respiration (fed-batch cultivation). However, the glucose effect in batch cultivations resulted in smaller epsilon O2 than delta h, while both values decreased in their absolute values. The evaluation of the heat energetic yield coefficient, together with the fraction of the available electrons transferred to O, contributed to the estimation of the extent of heat production through oxidative phosphorylation. (Refs. 19).

Yerushalmi, L.; Volesky, B.

1981-10-01

237

Diaminotoluenes induce intrachromosomal recombination and free radicals in Saccharomyces cerevisiae.  

PubMed

The carcinogenicity of aniline-based aromatic amines is poorly reflected by their activity in short-term mutagenicity assays such as the Salmonella typhimurium reverse mutation (Ames) assay. More information about the mechanism of action of such carcinogens is needed. Here we report the effects on DEL recombination in Saccharomyces cerevisiae of the carcinogen 2,4-diaminotoluene and its structural isomer 2,6-diaminotoluene, which is reported to be non-carcinogenic. Both compounds are detected as equally mutagenic in the Salmonella assay. In the absence of any external metabolizing system both compounds were recombinagenic in the DEL assay with the carcinogen being a more potent inducer of deletions than the non-carcinogen. In the presence of Aroclor-induced rat liver S9, however, the carcinogen 2,4-diaminotoluene became a 2-fold more potent inducer of deletions, and the non-carcinogen 2,6-diaminotoluene was rendered less toxic and no induced recombination was observed. 2,4-Diaminotoluene is distinguished from its non-carcinogen analog in the DEL assay, therefore, on the basis of a preferential activation of the carcinogen in the presence of a rat liver microsomal metabolizing system. Free radical species are produced by several carcinogens and have been implicated in carcinogenesis. We further investigated whether exposure of yeast to either 2,4-diaminotoluene or 2,6-diaminotoluene resulted in a rise in intracellular free radical species. The effects of the free radical scavenger N-acetylcysteine on toxicity and recombination induced by the two compounds and intracellular oxidation of the free radical-sensitive reporter compound dichlorofluorescin diacetate were studied. Both 2,4- and 2,6-diaminotoluene produced tree radical species in yeast, indicating that the reason for the differential activity of the compounds for induced deletions is not reflected in any difference in the production of free radical species. PMID:9434881

Brennan, R J; Schiestl, R H

1997-11-28

238

A vector set for systematic metabolic engineering in Saccharomyces cerevisiae  

PubMed Central

A set of shuttle vectors was constructed to facilitate expression of genes for metabolic engineering in Saccharomyces cerevisiae. Selectable markers include the URA3, TRP1, MET15, LEU2-d8, HIS3 and CAN1 genes. Differential expression of genes can be achieved as each marker is available on both CEN/ARS- and 2 ?-containing plasmids. Unique restriction sites downstream of TEF1, PGK1 or HXT7-391 promoters and upstream of the CYC1 terminator allow insertion of open-reading frame cassettes for expression. Furthermore, a fragment appropriate for integration into the genome via homologous recombination can be readily generated in a polymerase chain reaction. Vector marker genes are flanked by loxP recognition sites for the CreA recombinase to allow efficient site-specific marker deletion and recycling. Expression and copy number were characterized for representative high- and low-copy vectors carrying the different marker and promoter sequences. Metabolic engineering typically requires the stable introduction of multiple genes and genomic integration is often preferred. This requires an expanded number of stable expression sites relative to standard gene expression studies. This study demonstrated the practicality of polymerase chain reaction amplification of an expression cassette and genetic marker, and subsequent replacement of endogenous retrotransposons by homologous recombination with flanking sequences. Such reporters were expressed comparably to those inserted at standard integration loci. This expands the number of available characterized integration sites and demonstrates that such sites provide a virtually inexhaustible pool of integration targets for stable expression of multiple genes. Together these vectors and expression loci will facilitate combinatorial gene expression for metabolic engineering. PMID:20936606

Fang, Fang; Salmon, Kirsty; Shen, Michael W. Y.; Aeling, Kimberly A.; Ito, Elaine; Irwin, Becky; Tran, Uyen Phuong C.; Hatfield, G. Wesley; Da Silva, Nancy A.; Sandmeyer, Suzanne

2011-01-01

239

A vector set for systematic metabolic engineering in Saccharomyces cerevisiae.  

PubMed

A set of shuttle vectors was constructed to facilitate expression of genes for metabolic engineering in Saccharomyces cerevisiae. Selectable markers include the URA3, TRP1, MET15, LEU2-d8, HIS3 and CAN1 genes. Differential expression of genes can be achieved as each marker is available on both CEN/ARS- and 2 µ-containing plasmids. Unique restriction sites downstream of TEF1, PGK1 or HXT7-391 promoters and upstream of the CYC1 terminator allow insertion of open-reading frame cassettes for expression. Furthermore, a fragment appropriate for integration into the genome via homologous recombination can be readily generated in a polymerase chain reaction. Vector marker genes are flanked by loxP recognition sites for the CreA recombinase to allow efficient site-specific marker deletion and recycling. Expression and copy number were characterized for representative high- and low-copy vectors carrying the different marker and promoter sequences. Metabolic engineering typically requires the stable introduction of multiple genes and genomic integration is often preferred. This requires an expanded number of stable expression sites relative to standard gene expression studies. This study demonstrated the practicality of polymerase chain reaction amplification of an expression cassette and genetic marker, and subsequent replacement of endogenous retrotransposons by homologous recombination with flanking sequences. Such reporters were expressed comparably to those inserted at standard integration loci. This expands the number of available characterized integration sites and demonstrates that such sites provide a virtually inexhaustible pool of integration targets for stable expression of multiple genes. Together these vectors and expression loci will facilitate combinatorial gene expression for metabolic engineering. PMID:20936606

Fang, Fang; Salmon, Kirsty; Shen, Michael W Y; Aeling, Kimberly A; Ito, Elaine; Irwin, Becky; Tran, Uyen Phuong C; Hatfield, G Wesley; Da Silva, Nancy A; Sandmeyer, Suzanne

2011-02-01

240

Genetic effects of fresh cigarette smoke in Saccharomyces cerevisiae.  

PubMed

Ability of fresh cigarette smoke from University of Kentucky reference cigarette 2R1 to induce gene conversion, reverse mutation and mitotic crossing-over in strain D7 of Saccharomyces cerevisiae was examined. A closed cell suspension-recycle system using 2 peristaltic pumps interconnected to a single-port reverse-phase smoking machine was developed to provide complete exposure of cells to smoke within 0.2--10 sec of its generation. The exposed cells showed a dose-dependent increase in the frequency of all the 3 genetic endpoints examined. Cell age was an important factor with younger cells being more sensitive than older. Filtration studies showed that the gas phase possessed as much as 25% of the total whole-smoke activity. Activated charcoal reduced the activity of smoke in direct proportion to its amount in the filter. Acetate filter did not appreciably alter the activity. A comparison of whole smoke from various cigarettes showed that: (1) the nicotine content of a cigarette does not affect the genetic activity of smoke; (2) burley and flue-cured tobaccos have differential activity in gene conversion and reverse mutation systems; and (3) the genetic effects of whole smoke are not peculiar to tobacco pyrolysis because similar effects are produced by smokes from lettuce and other non-tobacco cigarettes. It is concluded that the yeast D7 system can be used effectively for the quantitative evaluation of genetic effects of smoke from different cigarettes, and both whole cigarette smoke and its gas phase possess mutagenic as well as recombinogenic activity that can be modified by the use of filters. PMID:6755230

Gairola, C

1982-09-01

241

Genetic Basis for Saccharomyces cerevisiae Biofilm in Liquid Medium  

PubMed Central

Biofilm-forming microorganisms switch between two forms: free-living planktonic and sessile multicellular. Sessile communities of yeast biofilms in liquid medium provide a primitive example of multicellularity and are clinically important because biofilms tend to have other growth characteristics than free-living cells. We investigated the genetic basis for yeast, Saccharomyces cerevisiae, biofilm on solid surfaces in liquid medium by screening a comprehensive deletion mutant collection in the ?1278b background and found 71 genes that were essential for biofilm development. Quantitative northern blots further revealed that AIM1, ASG1, AVT1, DRN1, ELP4, FLO8, FMP10, HMT1, KAR5, MIT1, MRPL32, MSS11, NCP1, NPR1, PEP5, PEX25, RIM8, RIM101, RGT1, SNF8, SPC2, STB6, STP22, TEC1, VID24, VPS20, VTC3, YBL029W, YBL029C-A, YFL054C, YGR161W-C, YIL014C-A, YIR024C, YKL151C, YNL200C, YOR034C-A, and YOR223W controlled biofilm through FLO11 induction. Almost all deletion mutants that were unable to form biofilms in liquid medium also lost the ability to form surface-spreading biofilm colonies (mats) on agar and 69% also lost the ability to grow invasively. The protein kinase A isoform Tpk3p functioned specifically in biofilm and mat formation. In a tpk3 mutant, transcription of FLO11 was induced three-fold compared with wild-type, but biofilm development and cell–cell adhesion was absent, suggesting that Tpk3p regulates FLO11 positive posttranscriptionally and negative transcriptionally. The study provides a resource of biofilm-influencing genes for additional research on biofilm development and suggests that the regulation of FLO11 is more complex than previously anticipated. PMID:25009170

Andersen, Kaj Scherz; Bojsen, Rasmus; S?rensen, Laura Gro Rejkjaer; Nielsen, Martin Weiss; Lisby, Michael; Folkesson, Anders; Regenberg, Birgitte

2014-01-01

242

[Construction and fermentation control of reductive TCA pathway for malic acid production in Saccharomyces cerevisiae].  

PubMed

Malic acid is widely used in food, and chemical industries. Through overexpressing pyruvate carboxylase and malate dehydrogenase in pdc1-deficient Saccharomyces cerevisiae, malic acid was successfully produced through the reductive TCA pathway. No malic acid was detected in wild type Saccharomyces cerevisiae, however, 45 mmol/L malic acid was produced in engineered strain, and the concentration of byproduct ethanol also reduced by 18%. The production of malic acid enhanced 6% by increasing the concentration of Ca2+. In addition, the final concentration reached 52.5 mmol/L malic acid by addition of biotin. The increasing is almost 16% higher than that of the original strain. PMID:24432663

Yan, Daojiang; Wang, Caixia; Zhou, Jiemin; Liu, Yilan; Yang, Maohua; Xing, Jianmin

2013-10-01

243

Idebenone treatment mediates the effect of menadione oxidative stress damage in Saccharomyces cerevisiae.  

PubMed

We investigated the damage caused by oxidative stress using the yeast Saccharomyces cerevisiae as a model biological system. After inducing oxidative stress with menadione, we were able to evaluate the extent of cellular oxidative stress by utilizing 2',7'-dichlorofluorescein diacetate (DCFH-DA) as a marker of the presence of reactive oxygen species. Cells were grown on different carbon sources in order to compare fermentative and oxidative metabolism. Under these conditions we evaluated the effectiveness of idebenone (2,3-dimethoxy-5-methyl-6-(10- hydroxydecyl)-1,4-benzoquinone) as a molecule that could relieve menadione-induced growth inhibition in Saccharomyces cerevisiae. PMID:22974201

Gamondi, Oliver; Chapela, Sebastián; Nievas, Inés; Burgos, Isabel; Alonso, Manuel; Stella, Carlos

2012-06-01

244

Rapid Identification and Enumeration of Saccharomyces cerevisiae Cells in Wine by Real-Time PCR  

PubMed Central

Despite the beneficial role of Saccharomyces cerevisiae in the food industry for food and beverage production, it is able to cause spoilage in wines. We have developed a real-time PCR method to directly detect and quantify this yeast species in wine samples to provide winemakers with a rapid and sensitive method to detect and prevent wine spoilage. Specific primers were designed for S. cerevisiae using the sequence information obtained from a cloned random amplified polymorphic DNA band that differentiated S. cerevisiae from its sibling species Saccharomyces bayanus, Saccharomyces pastorianus, and Saccharomyces paradoxus. The specificity of the primers was demonstrated for typical wine spoilage yeast species. The method was useful for estimating the level of S.?cerevisiae directly in sweet wines and red wines without preenrichment when yeast is present in concentrations as low as 3.8 and 5 CFU per ml. This detection limit is in the same order as that obtained from glucose-peptone-yeast growth medium (GPY). Moreover, it was possible to quantify S. cerevisiae in artificially contaminated samples accurately. Limits for accurate quantification in wine were established, from 3.8 × 105 to 3.8 CFU/ml in sweet wine and from 5 × 106 to 50?CFU/ml in red wine. PMID:16269715

Martorell, P.; Querol, A.; Fernandez-Espinar, M. T.

2005-01-01

245

Removal of Cr(VI) from ground water by Saccharomyces cerevisiae  

Microsoft Academic Search

Chromium can be removed from ground water by the unicellular yeast, Saccharomyces cerevisiae. Local ground water maintains chromium as CrO42- because of bicarbonate buffering and pH and Eh conditions (8.2 and +343 mV, respectively). In laboratory studies, we used commercially available, nonpathogenic S. cerevisiae to remove hexavalent chromium [Cr(VI)] from ground water. The influence of parameters such as temperature, pH,

P. Krauter; R. Martinelli; K. Williams; S. Martins

1996-01-01

246

Elimination of glycerol and replacement with alternative products in ethanol fermentation by Saccharomyces cerevisiae  

Microsoft Academic Search

Glycerol is a major by-product of ethanol fermentation by Saccharomyces cerevisiae and typically 2–3% of the sugar fermented is converted to glycerol. Replacing the NAD+-regenerating glycerol pathway in S. cerevisiae with alternative NADH reoxidation pathways may be useful to produce metabolites of biotechnological relevance. Under fermentative\\u000a conditions yeast reoxidizes excess NADH through glycerol production which involves NADH-dependent glycerol-3-phosphate dehydrogenases\\u000a (Gpd1p

Vishist K. Jain; Benoit Divol; Bernard A. Prior; Florian F. Bauer

247

Effects of cyclohexane, an industrial solvent, on the yeast Saccharomyces cerevisiae and on isolated yeast mitochondria  

SciTech Connect

Little information on the effects of cyclohexane at the cellular or subcellular level is available. In Saccharomyces cerevisiae, cyclohexane inhibited respiration and diverse energy-dependent processes. In mitochondria isolated from S. cerevisiae, oxygen uptake and ATP synthesis were inhibited, although ATPase activity was not affected. Cyclohexane effects were similar to those reported for beta-pinene and limonene, suggesting that the cyclohexane ring in these monoterpenes may be a determinant for their biological activities.

Uribe, S.; Rangel, P.; Espinola, G.; Aguirre, G. (Universidad Nacional Autonoma de Mexico, Mexico City (Mexico))

1990-07-01

248

Arrangement of genes TRP1 and TRP3 of Saccharomyces cerevisiae strains  

Microsoft Academic Search

The tryptophan biosynthetic genes TRP1 and TRP3 and partly also TRP2 and TRP4 have been compared by the technique of Southern hybridization and enzyme measurements in twelve wild isolates of Saccharomyces cerevisiae from natural sources of different continents, in the commonly used laboratory strain S. cerevisiae X2180-1A and in a Kluyveromyces marxianus strain. We could classify these strains into four

Gerhard Braus; Rolf Furter; Fransziska Prantl; Peter Niederberger; Ralf Hütter

1985-01-01

249

Alcoholic fermentation of carbon sources in biomass hydrolysates by Saccharomyces cerevisiae : current status  

Microsoft Academic Search

Fuel ethanol production from plant biomass hydrolysates by Saccharomyces cerevisiae is of great economic and environmental significance. This paper reviews the current status with respect to alcoholic fermentation of the main plant biomass-derived monosaccharides by this yeast. Wild-type S. cerevisiae strains readily ferment glucose, mannose and fructose via the Embden–Meyerhof pathway of glycolysis, while galactose is fermented via the Leloir

Antonius J. A. van Maris; Derek A. Abbott; Eleonora Bellissimi; Joost van den Brink; Marko Kuyper; Marijke A. H. Luttik; H. Wouter Wisselink; W. Alexander Scheffers; Johannes P. van Dijken; Jack T. Pronk

2006-01-01

250

The Reacquisition of Biotin Prototrophy in Saccharomyces cerevisiae Involved Horizontal Gene Transfer, Gene Duplication and Gene Clustering  

Microsoft Academic Search

The synthesis of biotin, a vitamin required for many carboxylation reactions, is a variable trait in Saccharomyces cerevisiae. Many S. cerevisiae strains, including common laboratory strains, contain only a partial biotin synthesis pathway. We here report the identification of the first step necessary for the biotin synthesis pathway in S. cerevisiae. The biotin auxotroph strain S288c was able to grow

Charles Hall; Fred S. Dietrich

2007-01-01

251

Construction of a controllable ?-carotene biosynthetic pathway by decentralized assembly strategy in Saccharomyces cerevisiae.  

PubMed

Saccharomyces cerevisiae is an important platform organism for the synthesis of a great number of natural products. However, the assembly of controllable and genetically stable heterogeneous biosynthetic pathways in S. cerevisiae still remains a significant challenge. Here, we present a strategy for reconstructing controllable multi-gene pathways by employing the GAL regulatory system. A set of marker recyclable integrative plasmids (pMRI) was designed for decentralized assembly of pathways. As proof-of-principle, a controllable ?-carotene biosynthesis pathway (?16?kb) was reconstructed and optimized by repeatedly using GAL10-GAL1 bidirectional promoters with high efficiency (80-100%). By controling the switch time of the pathway, production of 11?mg/g DCW of total carotenoids (72.57?mg/L) and 7.41?mg/g DCW of ?-carotene was achieved in shake-flask culture. In addition, the engineered yeast strain exhibited high genetic stability after 20 generations of subculture. The results demonstrated a controllable and genetically stable biosynthetic pathway capable of increasing the yield of target products. Furthermore, the strategy presented in this study could be extended to construct other pathways in S. cerevisisae. PMID:23860829

Xie, Wenping; Liu, Min; Lv, Xiaomei; Lu, Wenqiang; Gu, Jiali; Yu, Hongwei

2014-01-01

252

Direct Conversion of Xylan to Ethanol by Recombinant Saccharomyces cerevisiae Strains Displaying an Engineered Minihemicellulosome  

PubMed Central

Arabinoxylan is a heteropolymeric chain of a ?-1,4-linked xylose backbone substituted with arabinose residues, representing a principal component of plant cell walls. Here we developed recombinant Saccharomyces cerevisiae strains as whole-cell biocatalysts capable of combining hemicellulase production, xylan hydrolysis, and hydrolysate fermentation into a single step. These strains displayed a series of uni-, bi-, and trifunctional minihemicellulosomes that consisted of a miniscaffoldin (CipA3/CipA1) and up to three chimeric enzymes. The miniscaffoldin derived from Clostridium thermocellum contained one or three cohesin modules and was tethered to the cell surface through the S. cerevisiae a-agglutinin adhesion receptor. Up to three types of hemicellulases, an endoxylanase (XynII), an arabinofuranosidase (AbfB), and a ?-xylosidase (XlnD), each bearing a C-terminal dockerin, were assembled onto the miniscaffoldin by high-affinity cohesin-dockerin interactions. Compared to uni- and bifunctional minihemicellulosomes, the resulting quaternary trifunctional complexes exhibited an enhanced rate of hydrolysis of arabinoxylan. Furthermore, with an integrated d-xylose-utilizing pathway, the recombinant yeast displaying the bifunctional minihemicellulosome CipA3-XynII-XlnD could simultaneously hydrolyze and ferment birchwood xylan to ethanol with a yield of 0.31 g per g of sugar consumed. PMID:22447594

Sun, Jie; Wen, Fei; Si, Tong; Xu, Jian-He

2012-01-01

253

Saccharomyces cerevisiae Is Permissive for Replication of Bovine Papillomavirus Type 1  

PubMed Central

We recently demonstrated that Saccharomyces cerevisiae protoplasts can take up bovine papillomavirus type 1 (BPV1) virions and that viral episomal DNA is replicated after uptake. Here we demonstrate that BPV virus-like particles are assembled in infected S. cerevisiae cultures from newly synthesized capsid proteins and also package newly synthesized DNA, including full-length and truncated viral DNA and S. cerevisiae-derived DNA. Virus particles prepared in S. cerevisiae are able to convey packaged DNA to Cos1 cells and to transform C127 cells. Infectivity was blocked by antisera to BPV1 L1 but not antisera to BPV1 E4. We conclude that S. cerevisiae is permissive for the replication of BPV1 virus. PMID:12414966

Zhao, Kong-Nan; Frazer, Ian H.

2002-01-01

254

Elucidating TOR Signaling and Rapamycin Action: Lessons from Saccharomyces cerevisiae  

PubMed Central

TOR (target of rapamycin) is a phosphatidylinositol kinase-related protein kinase that controls cell growth in response to nutrients. Rapamycin is an immunosuppressive and anticancer drug that acts by inhibiting TOR. The modes of action of TOR and rapamycin are remarkably conserved from S. cerevisiae to humans. The current understanding of TOR and rapamycin is derived largely from studies with S. cerevisiae. In this review, we discuss the contributions made by S. cerevisiae to understanding rapamycin action and TOR function. PMID:12456783

Crespo, Jose L.; Hall, Michael N.

2002-01-01

255

Crystal structure of Saccharomyces cerevisiae 6-phosphogluconate dehydrogenase Gnd1  

PubMed Central

Background As the third enzyme of the pentose phosphate pathway, 6-phosphogluconate dehydrogenase (6PGDH) is the main generator of cellular NADPH. Both thioredoxin reductase and glutathione reductase require NADPH as the electron donor to reduce oxidized thioredoxin or glutathione (GSSG). Since thioredoxin and GSH are important antioxidants, it is not surprising that 6PGDH plays a critical role in protecting cells from oxidative stress. Furthermore the activity of 6PGDH is associated with several human disorders including cancer and Alzheimer's disease. The 3D structural investigation would be very valuable in designing small molecules that target this enzyme for potential therapeutic applications. Results The crystal structure of 6-phosphogluconate dehydrogenase (6PGDH/Gnd1) from Saccharomyces cerevisiae has been determined at 2.37 Å resolution by molecular replacement. The overall structure of Gnd1 is a homodimer with three domains for each monomer, a Rossmann fold NADP+ binding domain, an all-? helical domain contributing the majority to hydrophobic interaction between the two subunits and a small C-terminal domain penetrating the other subunit. In addition, two citrate molecules occupied the 6PG binding pocket of each monomer. The intact Gnd1 had a Km of 50 ± 9 ?M for 6-phosphogluconate and of 35 ± 6 ?M for NADP+ at pH 7.5. But the truncated mutants without the C-terminal 35, 39 or 53 residues of Gnd1 completely lost their 6PGDH activity, despite remaining the homodimer in solution. Conclusion The overall tertiary structure of Gnd1 is similar to those of 6PGDH from other species. The substrate and coenzyme binding sites are well conserved, either from the primary sequence alignment, or from the 3D structural superposition. Enzymatic activity assays suggest a sequential mechanism of catalysis, which is in agreement with previous studies. The C-terminal domain of Gnd1 functions as a hook to further tighten the dimer, but it is not necessary for the dimerization. This domain also works as a lid on the substrate binding pocket to control the binding of substrate and the release of product, so it is indispensable for the 6PGDH activity. Moreover, the co-crystallized citrate molecules, which mimic the binding mode of the substrate 6-phosphogluconate, provided us a novel strategy to design the 6PDGH inhibitors. PMID:17570834

He, Weiwei; Wang, Yi; Liu, Wei; Zhou, Cong-Zhao

2007-01-01

256

Defective Interference in the Killer System of Saccharomyces cerevisiae  

PubMed Central

The K1 killer virus (or plasmid) of Saccharomyces cerevisiae is a noninfectious double-stranded RNA genome found intracellularly packaged in an icosahedral capsid. This genome codes for a protein toxin and for resistance to that toxin. Defective interfering virus mutants are deletion derivatives of the killer virus double-stranded RNA genome; such mutants are called suppressive. Unlike strains carrying the wild-type genome, strains with these deletion derivatives are neither toxin producers nor toxin resistant. If both the suppressive and the wildtype virus are introduced into the same cell, most progeny become toxin-sensitive nonkillers (J. M. Somers, Genetics 74:571-579, 1973). Diploids formed by the mating of a killer with a suppressive strain were grown in liquid culture, and RNA was extracted from samples taken up to 41 generations after the mating. The ratio of killer RNA to suppressive RNA decreased with increasing generations; by 41 generations the killer RNA was barely detectable. The copy numbers of the suppressive genome and its parental killer were virtually the same in isogenic strains, as were the growth rates of diploid strains containing either virus alone. Therefore, suppressiveness, not being due to segregation or overgrowth by faster growing segregants, is likely due to preferential replication or maintenance of the suppressive genome. Three suppressive viruses, all derivatives of the same killer virus (T. K. Sweeney et al., Genetics 84:27-42, 1976), did not coexist stably. The evidence strongly indicates that the largest genome of the three slowly suppressed both of the smaller genomes, showing that larger genomes can suppress smaller ones and that suppression can occur between two suppressives. Of 48 isolates of strains carrying the suppressive viruses, 5 had newly detectable RNA species, all larger than the original suppressive genomes. At least seven genes necessary for maintenance of the wild-type killer virus (MAK genes) were needed by a suppressive mutant. No effect of ski mutations (affecting regulation of killer virus double-stranded RNA replication) on suppressiveness was observed. Images PMID:16789236

Ridley, Susan Porter; Wickner, Reed B.

1983-01-01

257

Glucose induces rapid changes in the secretome of Saccharomyces cerevisiae  

PubMed Central

Background Protein secretion is a fundamental process in all living cells. Proteins can either be secreted via the classical or non-classical pathways. In Saccharomyces cerevisiae, gluconeogenic enzymes are in the extracellular fraction/periplasm when cells are grown in media containing low glucose. Following a transfer of cells to high glucose media, their levels in the extracellular fraction are reduced rapidly. We hypothesized that changes in the secretome were not restricted to gluconeogenic enzymes. The goal of the current study was to use a proteomic approach to identify extracellular proteins whose levels changed when cells were transferred from low to high glucose media. Results We performed two iTRAQ experiments and identified 347 proteins that were present in the extracellular fraction including metabolic enzymes, proteins involved in oxidative stress, protein folding, and proteins with unknown functions. Most of these proteins did not contain typical ER-Golgi signal sequences. Moreover, levels of many of these proteins decreased upon a transfer of cells from media containing low to high glucose media. Using an extraction procedure and Western blotting, we confirmed that the metabolic enzymes (glyceraldehyde-3-phosphate dehydrogenase, 3-phosphoglycerate kinase, glucose-6-phosphate dehydrogenase, pyruvate decarboxylase), proteins involved in oxidative stress (superoxide dismutase and thioredoxin), and heat shock proteins (Ssa1p, Hsc82p, and Hsp104p) were in the extracellular fraction during growth in low glucose and that the levels of these extracellular proteins were reduced when cells were transferred to media containing high glucose. These proteins were associated with membranes in vesicle-enriched fraction. We also showed that small vesicles were present in the extracellular fraction in cells grown in low glucose. Following a transfer from low to high glucose media for 30 minutes, 98% of these vesicles disappeared from the extracellular fraction. Conclusions Our data indicate that transferring cells from low to high glucose media induces a rapid decline in levels of a large number of extracellular proteins and the disappearance of small vesicles from the extracellular fraction. Therefore, we conclude that the secretome undergoes dynamic changes during transition from glucose-deficient to glucose-rich media. Most of these extracellular proteins do not contain typical ER signal sequences, suggesting that they are secreted via the non-classical pathway. PMID:24520859

2014-01-01

258

The effect of supplementing cows with live yeast, Saccharomyces cerevisiae, on ciliate fauna and ruminal fermentation  

Microsoft Academic Search

The infl uence of a live culture of Saccharomyces cerevisiae on the number of ciliates, activity of carboxymethylcellulose- (CMC), xylan- and starch-degrading enzymes, as well as the concentration of VFA in the rumen of two cows was examined. The animals were fed either hay and concentrate alone or supplemented with live yeast given at the rate of 5 g\\/d. It

B. Kowalik; T. Micha?owski; J. J. Paj?k; M. Taciak; J. Rawa

259

Unconventional Genomic Architecture in the Budding Yeast Saccharomyces cerevisiae Masks the Nested Antisense Gene NAG1  

Microsoft Academic Search

The genomic architecture of the budding yeast Saccharomyces cerevisiae is typical of other eukaryotes in that genes are spatially organized into discrete and nonoverlapping units. Inherent in this organizational model is the assumption that protein-coding sequences do not overlap completely. Here, we present evidence to the contrary, defining a previously overlooked yeast gene, NAG1 (for nested antisense gene) nested entirely

Jun Ma; Craig J. Dobry; Damian J. Krysan; Anuj Kumar

2008-01-01

260

Two novel methyltransferases acting upon eukaryotic elongation factor 1A in Saccharomyces cerevisiae  

E-print Network

A (eEF1A) is an abundant cytosolic protein in Saccharomyces cerevisiae and is well conserved amongst of two genes coding for putative methyltransferases results in a loss in mass of eEF1A. Deletion lysine methyltransferases, results in an eEF1A mass loss corresponding to a single methyl group. Dele

Clarke, Steven

261

Dissociation of Import of the Rieske Iron-Sulfur Protein into Saccharomyces cerevisiae Mitochondria from Proteolytic  

E-print Network

Dissociation of Import of the Rieske Iron-Sulfur Protein into Saccharomyces cerevisiae Mitochondria into the matrix space of mitochondria by inhibiting a step other than proteolysis of the presequence. The Rieske. The iron-sulfur protein is then post-translationally imported into the mitochondria where it is inserted

Trumpower, Bernard L.

262

Comparison of the Small Molecule Metabolic Enzymes of Escherichia coli and Saccharomyces cerevisiae  

Microsoft Academic Search

The comparison of the small molecule metabolism pathways in Escherichia coli and Saccharomyces cerevisiae (yeast) shows that 271 enzymes are common to both organisms. These common enzymes involve 384 gene products in E. coli and 390 in yeast, which are between one half and two thirds of the gene products of small molecule metabolism in E. coli and yeast, respectively.

Oliver Jardine; Julian Gough; Cyrus Chothia; Sarah A. Teichmann

2002-01-01

263

Genes involved in the control of nuclear fusion during the sexual cycle of Saccharomyces cerevisiae  

Microsoft Academic Search

Mutants of Saccharomyces cerevisiae defective for nuclear fusion have been isolated. Their mutations have been characterized by meiotic analysis, dominance-recessivity and complementation. Twelve of the mutations are allelic to the previously described kar 1-1; five affect a second gene designated KAR 2 and three affect a third gene designated KAR 3. There is evidence suggesting that other two mutants are

Julio Polaina; Jaime Conde

1982-01-01

264

Saccharomyces cerevisiae in the stationary phase as a model organism — characterization at cellular and proteome level  

Microsoft Academic Search

The yeast Saccharomyces cerevisiae has been used as a model organism to investigate responses to different environmental stressors. The importance of their conclusions has been expanded to human cells. The experiments were done with exponentially growing cells, which do not resemble human cells. Human and other eukaryotic cells spend the greater part of their lives in a quiescent state, known

Teja Zakrajšek; Peter Raspor; Polona Jamnik

2011-01-01

265

HOCl-mediated cell death and metabolic dysfunction in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

The nature of oxidative damage to Saccharomyces cerevisiae caused by levels of HOCl that inhibit cell replication was explored with the intent of identifying the loci of lethal lesions. Functions of cytosolic enzymes and organelles that are highly sensitive to inactivation by HOCl, including aldolase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and the mitochondrion, were only marginally affected by exposure of the yeast

David A King; Diane M Hannum; Jian-Shen Qi; James K Hurst

2004-01-01

266

Arabinose and xylose fermentation by recombinant Saccharomyces cerevisiae expressing a fungal pentose utilization pathway  

Microsoft Academic Search

BACKGROUND: Sustainable and economically viable manufacturing of bioethanol from lignocellulose raw material is dependent on the availability of a robust ethanol producing microorganism, able to ferment all sugars present in the feedstock, including the pentose sugars L-arabinose and D-xylose. Saccharomyces cerevisiae is a robust ethanol producer, but needs to be engineered to achieve pentose sugar fermentation. RESULTS: A new recombinant

Maurizio Bettiga; Oskar Bengtsson; Bärbel Hahn-Hägerdal; Marie F Gorwa-Grauslund

2009-01-01

267

Identification of a gene conferring resistance to zinc and cadmium ions in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

A DNA fragment conferring resistance to zinc and cadmium ions in the yeast Saccharomyces cerevisiae was isolated from a library of yeast genomic DNA. Its nucleotide sequence revealed the presence of a single open reading frame (ORF; 1326 bp) having the potential to encode a protein of 442 amino acid residues (molecular mass of 48.3 kDa). A frameshift mutation introduced

Akihito Kamizono; Masafumi Nishizawa; Yutaka Teranishi; Kousaku Murata; Akira Kimura

1989-01-01

268

Lack of carbon catabolite inactivation in a mutant of Saccharomyces cerevisiae with reduced hexokinase activity  

Microsoft Academic Search

A mutant of Saccharomyces cerevisiae with reduced hexokinase activity and deficient in carbon catabolite inactivation is described. The reason for this lack of inactivation is not a lowered concentration of glycolysis metabolites or other low molecular effectors such as glucose, and ATP. The results point to the hexose phosphorylation step as initiator for carbon catabolite inactivation. It appears that one

K.-D. Entian

1977-01-01

269

A Saccharomyces cerevisiae Genome-Wide Mutant Screen for Altered Sensitivity to K1 Killer Toxin  

Microsoft Academic Search

Using the set of Saccharomyces cerevisiae mutants individually deleted for 5718 yeast genes, we screened for altered sensitivity to the antifungal protein, K1 killer toxin, that binds to a cell wall -glucan receptor and subsequently forms lethal pores in the plasma membrane. Mutations in 268 genes, including 42 in genes of unknown function, had a phenotype, often mild, with 186

Nicolas Page ´; Manon Gerard-Vincent; Patrice Menard; Maude Beaulieu; Masayuki Azuma; Gerrit J. P. Dijkgraaf; Thuy Nguyen; Tim Dowse; Anne-Marie Sdicu; Howard Bussey

270

Minear, S., et al Curcumin inhibits growth of Saccharomyces cerevisiae1  

E-print Network

Minear, S., et al 1 Curcumin inhibits growth of Saccharomyces cerevisiae1 through iron chelation2 3 of print on 9 September 2011 #12;Minear, S., et al 2 Abstract (limit 250 words)46 47 Curcumin, a polyphenol of ailments. Interest in curcumin has49 increased recently, with on-going clinical trials exploring curcumin

Stearns, Tim

271

The use of plasmid DNA to probe DNA repair functions in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

The survival of plasmid YRp12 treated in vitro with ultraviolet- or ?-radiation, or with restriction endonucleases, has been used to investigate in vivo RAD gene activity in Saccharomyces cerevisiae. Yields of pyrmidine dimers or single and double strand breaks in plasmid DNA were assayed by physical methods. The biological effects of these damages were assayed by transformation of wild-type cells

Charles I. White; Steven G. Sedgwick

1985-01-01

272

PCR on yeast colonies: an improved method for glyco-engineered Saccharomyces cerevisiae  

PubMed Central

Background Saccharomyces cerevisiae is extensively used in bio-industries. However, its genetic engineering to introduce new metabolism pathways can cause unexpected phenotypic alterations. For example, humanisation of the glycosylation pathways is a high priority pharmaceutical industry goal for production of therapeutic glycoproteins in yeast. Genomic modifications can lead to several described physiological changes: biomass yields decrease, temperature sensitivity or cell wall structure modifications. We have observed that deletion of several N-mannosyltransferases in Saccharomyces cerevisiae, results in strains that can no longer be analyzed by classical PCR on yeast colonies. Findings In order to validate our glyco-engineered Saccharomyces cerevisiae strains, we developed a new protocol to carry out PCR directly on genetically modified yeast colonies. A liquid culture phase, combined with the use of a Hot Start DNA polymerase, allows a 3-fold improvement of PCR efficiency. The results obtained are repeatable and independent of the targeted sequence; as such the protocol is well adapted for intensive screening applications. Conclusions The developed protocol enables by-passing of many of the difficulties associated with PCR caused by phenotypic modifications brought about by humanisation of the glycosylation in yeast and allows rapid validation of glyco-engineered Saccharomyces cerevisiae cells. It has the potential to be extended to other yeast strains presenting cell wall structure modifications. PMID:23688076

2013-01-01

273

The uptake of different iron salts by the yeast Saccharomyces cerevisiae  

PubMed Central

Yeasts can be enriched with microelements, including iron; however, special physicochemical conditions are required to formulate a culture media that promotes both yeast growth and iron uptake. Different iron sources do not affect biomass formation; however, considering efficacy, cost, stability, and compatibility with Saccharomyces cerevisiae metabolism, ferrous sulphate is recommended. PMID:25242932

Gaensly, Fernanda; Picheth, Geraldo; Brand, Debora; Bonfim, Tania M.B.

2014-01-01

274

Proof and evolutionary analysis of ancient genome duplication in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

Whole-genome duplication followed by massive gene loss and specialization has long been postulated as a powerful mechanism of evolutionary innovation. Recently, it has become possible to test this notion by searching complete genome sequence for signs of ancient duplication. Here, we show that the yeast Saccharomyces cerevisiae arose from ancient whole-genome duplication, by sequencing and analysing Kluyveromyces waltii, a related

Bruce W. Birren; Manolis Kellis; Eric S. Lander

2004-01-01

275

Trans-acting regulatory variation in Saccharomyces cerevisiae and the role of transcription factors  

Microsoft Academic Search

Natural genetic variation can cause significant differences in gene expression, but little is known about the polymorphisms that affect gene regulation. We analyzed regulatory variation in a cross between laboratory and wild strains of Saccharomyces cerevisiae. Clustering and linkage analysis defined groups of coregulated genes and the loci involved in their regulation. Most expression differences mapped to trans-acting loci. Positional

Gaël Yvert; Rachel B Brem; Jacqueline Whittle; Joshua M Akey; Eric Foss; Erin N Smith; Rachel Mackelprang; Leonid Kruglyak

2003-01-01

276

Quantitative Analysis of Ceramide III of Saccharomyces cerevisiae by Normal Phase HPLC  

Microsoft Academic Search

Ceramide III was prepared by the cultivation of Saccharomyces cerevisiae. Ceramide III was partitioned from the cell extracts by solvent extraction and analyzed by normal phased high performance liquid chromatography (NP?HPLC) using evaporative light scattering detector (ELSD) and mass spectrometer. The mobile phase was composed of chloroform and methanol. One linear gradient mode was applied to gain proper analysis of

D. H. Kang; S. P. Hong; K. H. Row

2003-01-01

277

Identification of Genes Required for Normal Pheromone-Induced Cell ~ Polarization in Saccharomyces cerevisiae  

Microsoft Academic Search

ABSTRACT In response to mating pheromones, cells of the yeast Saccharomyces cerevisiae adopt a polarized “shmoo” morphology, in which the cytoskeleton and proteins involved in mating are localized to a cell- surface projection. This polarization , yet to be determined. We discuss the possible roles of these gene products in establishing cell polarity during mating. M ANY cell types generate

Janet Chenevert; Nicole Val; Ira Herskowitz

278

A genome-wide deletion mutant screen identifies pathways affected by nickel sulfate in Saccharomyces cerevisiae  

Microsoft Academic Search

BACKGROUND: The understanding of the biological function, regulation, and cellular interactions of the yeast genome and proteome, along with the high conservation in gene function found between yeast genes and their human homologues, has allowed for Saccharomyces cerevisiae to be used as a model organism to deduce biological processes in human cells. Here, we have completed a systematic screen of

Adriana Arita; Xue Zhou; Thomas P Ellen; Xin Liu; Jingxiang Bai; John P Rooney; Adrienne Kurtz; Catherine B Klein; Wei Dai; Thomas J Begley; Max Costa

2009-01-01

279

Display of wasp venom allergens on the cell surface of Saccharomyces cerevisiae  

Microsoft Academic Search

BACKGROUND: Yeast surface display is a technique, where the proteins of interest are expressed as fusions with yeast surface proteins and thus remain attached to the yeast cell wall after expression. Our purpose was to study whether allergens expressed on the cell surface of baker's yeast Saccharomyces cerevisiae preserve their native allergenic properties and whether the yeast native surface glycoproteins

Irina Borodina; Bettina M Jensen; Ib Søndergaard; Lars K Poulsen

2010-01-01

280

Production of sorbitol and ethanol from Jerusalem artichokes by Saccharomyces cerevisiae ATCC 36859  

Microsoft Academic Search

This study shows the possibile use of Jerusalem artichokes for the production of sorbitol and ethanol by Saccharomyces cerevisiae ATCC 36859. Ethanol was produced from the beginning of the process, while sorbitol production started after glucose had been entirely consumed from Jerusalem artichoke (J.a.) juice. The importance of yeast extract and inoculum concentrations on the production of sorbitol from the

Z. Duvnjak; G. Turcotte; Z. D. Duan

1991-01-01

281

Discrete Targeting Signals Direct Pmp47 to Oleate-induced Peroxisomes in Saccharomyces cerevisiae*  

E-print Network

Discrete Targeting Signals Direct Pmp47 to Oleate-induced Peroxisomes in Saccharomyces cerevisiae 75390-9041 Pmp47 is a peroxisomal membrane protein consisting of six transmembrane domains (TMDs). We for peroxisomal tar- geting, and similar basic targeting motifs have been found in other peroxisomal membrane

Brand, Paul H.

282

Saccharomyces cerevisiae as a Model System To Define the Chromosomal Instability Phenotype  

Microsoft Academic Search

Translocations, deletions, and chromosome fusions are frequent events seen in cancers with genome insta- bility. Here we analyzed 358 genome rearrangements generated in Saccharomyces cerevisiae selected by the loss of the nonessential terminal segment of chromosome V. The rearrangements appeared to be generated by both nonhomologous end joining and homologous recombination and targeted all chromosomes. Fifteen percent of the rearrangements

Christopher D. Putnam; Vincent Pennaneach; Richard D. Kolodner

2005-01-01

283

Induction of Global Stress Response in Saccharomyces cerevisiae Cells Lacking Telomerase  

Microsoft Academic Search

Cellular senescence is a major intermediate step from healthy cells toward tumor cells. By using microarrays that simultaneously examine the transcription levels of 6,200 Saccharomyces cerevisiae genes, we show that 45 gene transcript levels are increased and 11 are decreased after exposure to telomere shortening and cellular senescence in a telomerase-deficient mutant. About half of the genes that showed increased

Shu-Chun Teng; Charles Epstein; Yun-Luen Tsai; Hui-Wen Cheng; Hung-Lin Chen; Jing-Jer Lin

2002-01-01

284

Note. Morphological Changes in Saccharomyces cerevisiae during the Second Fermentation of Sparkling Wines  

Microsoft Academic Search

This study shows the morphological changes of Saccharomyces cerevisiae EC1118 during the second fermentation of Spanish cava wines, in relation with progression of fermentation and aging. In the first stages of active fermentation, and associated with the increase in viable counts, budding cells and a relative homogeneity in cell size were observed. Close to the moment of sugar exhaustion cells

R. Gonzalez; A. Vian; A. V. Carrascosa

2008-01-01

285

A Recombinant Saccharomyces cerevisiae Strain Overproducing Mannoproteins Stabilizes Wine against Protein Haze  

Microsoft Academic Search

Stabilization against protein haze was one of the first positive properties attributed to yeast mannoproteins in winemaking. In previous work we demonstrated that deletion of KNR4 leads to increased mannoprotein release in laboratory Saccharomyces cerevisiae strains. We have now constructed strains with KNR4 deleted in two different industrial wine yeast backgrounds. This required replacement of two and three alleles of

Daniel Gonzalez-Ramos; Eduardo Cebollero; Ramon Gonzalez

2008-01-01

286

A FTIR microspectroscopy study of autolysis in cells of the wine yeast Saccharomyces cerevisiae  

Microsoft Academic Search

The present paper reports the first application of FTIR microspectroscopy in the mid-infrared range to study the major biochemical changes associated with autolysis in yeast cells. Measurements were done both in transmission and in attenuated total reflection (ATR) mode on cells of Saccharomyces cerevisiae strain EC1118 before and after induction of the autolytic process in a model wine medium and

E. Burattini; M. Cavagna; R. Dell’Anna; F. Malvezzi Campeggi; F. Monti; F. Rossi; S. Torriani

2008-01-01

287

Modeling growth and telomere dynamics in Saccharomyces cerevisiae Peter Olofsson a,, Alison A. Bertuch b  

E-print Network

Modeling growth and telomere dynamics in Saccharomyces cerevisiae Peter Olofsson a,Ã?, Alison A Accepted 2 December 2009 MSC: 60G99 60K99 62P10 92D25 Keywords: Telomere Branching process Yeast Fibonacci of slowing due to critical telomere shortening. The explanation for this phenomenon is that some cells engage

Olofsson, Peter

288

Ethanol-Independent Biofilm Formation by a Flor Wine Yeast Strain of Saccharomyces cerevisiae?  

PubMed Central

Flor strains of Saccharomyces cerevisiae form a biofilm on the surface of wine at the end of fermentation, when sugar is depleted and growth on ethanol becomes dependent on oxygen. Here, we report greater biofilm formation on glycerol and ethyl acetate and inconsistent formation on succinic, lactic, and acetic acids. PMID:20435772

Zara, Severino; Gross, Michael K.; Zara, Giacomo; Budroni, Marilena; Bakalinsky, Alan T.

2010-01-01

289

Catalase Overexpression Reduces Lactic Acid-Induced Oxidative Stress in Saccharomyces cerevisiae  

Microsoft Academic Search

Industrial production of lactic acid with the current pyruvate decarboxylase-negative Saccharomyces cerevisiae strains requires aeration to allow for respiratory generation of ATP to facilitate growth and, even under nongrowing conditions, cellular maintenance. In the current study, we observed an inhibition of aerobic growth in the presence of lactic acid. Unexpectedly, the cyb2{Delta} reference strain, used to avoid aerobic consumption of

Derek A. Abbott; Erwin Suir; Giang-Huong Duong; Erik de Hulster; Jack T. Pronk; Antonius J. A. van Maris

2009-01-01

290

The Role of Interelement Selection in Saccharomyces cerevisiae Ty Element Evolution  

E-print Network

The Role of Interelement Selection in Saccharomyces cerevisiae Ty Element Evolution I. King Jordan by their ability to replicate faster than the host genomes in which they reside. Elements with higher rates of genomic replication possess a selective advan- tage over less active elements. Retrotransposon popula

Jordan, King

291

Behaviour of Saccharomyces cerevisiae cells entrapped in a polyacrylamide gel and performing alcoholic fermentation  

Microsoft Academic Search

The behaviour of Saccharomyces cerevisiae cells entrapped in a polyacrylamide gel was studied during their continuous function in an ethanol-producing reactor. Polymerization destroys 40% to 80% of the cells, depending on their physiological state. A three day adaptation phase is required before ethanol production stabilizes and this phase corresponds to an increase in cell concentration in the gels and to

M. H. Siess; C. Divies

1981-01-01

292

A mathematical model of the mating signal transduction pathway in the yeast Saccharomyces cerevisiae. Final report  

SciTech Connect

Outline of two major goals in my proposal for this fellowship. First goal having no previous training in biology, was to become knowledgeable of the paradigms, experimental techniques, and current research interests of molecular biology. Second goal was to construct a mathematical model of the mating signal transduction pathway in the yeast Saccharomyces cerevisiae.

Thomas Ivan Milac

1998-09-14

293

Genetic studies of the pyrimidine permeases from Saccharomyces cerevisiae: lack of intragenic complementation.  

PubMed

A search for intragenic complementation of mutants of the cytosine and uracil permeases of Saccharomyces cerevisiae was made. Among numerous diploid pairs of mutants of the cytosine permease gene no complementation was found. Similarly negative results were obtained with pairs of mutants of the uracil permease. The significance of these results is discussed. PMID:331085

Parlebas, N; Chevallier, M R

1977-07-20

294

Kinetics studies on ethanol production from banana peel waste using mutant strain of Saccharomyces cerevisiae  

Microsoft Academic Search

Five different mutant strains were developed from the wild strain of Saccharomyces cerevisiae (MTCC No.287) using UV irradiation technique by varying the exposure timings. All the mutant cultures were used for ethanol production using banana peel as a substrate in a batch fermenter. The effect of temperature, pH and initial substrate concentration on ethanol production were studied and optimized. The

K Manikandan; V Saravanan; T Viruthagiri

295

High vanillin tolerance of an evolved Saccharomyces cerevisiae strain owing to its enhanced vanillin reduction and antioxidative capacity.  

PubMed

The phenolic compounds present in hydrolysates pose significant challenges for the sustainable lignocellulosic materials refining industry. Three Saccharomyces cerevisiae strains with high tolerance to lignocellulose hydrolysate were obtained through ethyl methanesulfonate mutation and adaptive evolution. Among them, strain EMV-8 exhibits specific tolerance to vanillin, a phenolic compound common in lignocellulose hydrolysate. The EMV-8 maintains a specific growth rate of 0.104 h(-1) in 2 g L(-1) vanillin, whereas the reference strain cannot grow. Physiological studies revealed that the vanillin reduction rate of EMV-8 is 1.92-fold higher than its parent strain, and the Trolox equivalent antioxidant capacity of EMV-8 is 15 % higher than its parent strain. Transcriptional analysis results confirmed an up-regulated oxidoreductase activity and antioxidant activity in this strain. Our results suggest that enhancing the antioxidant capacity and oxidoreductase activity could be a strategy to engineer S. cerevisiae for improved vanillin tolerance. PMID:25261986

Shen, Yu; Li, Hongxing; Wang, Xinning; Zhang, Xiaoran; Hou, Jin; Wang, Linfeng; Gao, Nan; Bao, Xiaoming

2014-11-01

296

Isolation, DNA sequence, and regulation of a Saccharomyces cerevisiae gene that encodes DNA strand transfer protein alpha.  

PubMed Central

DNA strand transfer protein alpha (STP alpha) from meiotic Saccharomyces cerevisiae cells promotes homologous pairing of DNA without any nucleotide cofactor in the presence of yeast single-stranded DNA binding protein. This gene (DNA strand transferase 1, DST1) encodes a 309-amino-acid protein with a predicted molecular mass of 34,800 Da. The STP alpha protein level is constant in both mitotic and meiotic cells, but during meiosis the polypeptide is activated by an unknown mechanism, resulting in a large increase in its specific activity. A dst1::URA3/dst1::URA3 mutant grows normally in mitotic media; however, meiotic cells exhibit a greatly reduced induction of both DNA strand transfer activity and intragenic recombination between his1 heteroalleles. Spore viability is normal. These results suggest that DST1 is required for much of the observed induction of homologous recombination in S. cerevisiae during meiosis but not for normal sporulation. Images PMID:1850099

Clark, A B; Dykstra, C C; Sugino, A

1991-01-01

297

Genomic Screen for Vacuolar Protein Sorting Genes in Saccharomyces cerevisiaeD?  

PubMed Central

The biosynthetic sorting of hydrolases to the yeast vacuole involves transport along two distinct routes referred to as the carboxypeptidase Y and alkaline phosphatase pathways. To identify genes involved in sorting to the vacuole, we conducted a genome-wide screen of 4653 homozygous diploid gene deletion strains of Saccharomyces cerevisiae for missorting of carboxypeptidase Y. We identified 146 mutant strains that secreted strong-to-moderate levels of carboxypeptidase Y. Of these, only 53 of the corresponding genes had been previously implicated in vacuolar protein sorting, whereas the remaining 93 had either been identified in screens for other cellular processes or were only known as hypothetical open reading frames. Among these 93 were genes encoding: 1) the Ras-like GTP-binding proteins Arl1p and Arl3p, 2) actin-related proteins such as Arp5p and Arp6p, 3) the monensin and brefeldin A hypersensitivity proteins Mon1p and Mon2p, and 4) 15 novel proteins designated Vps61p-Vps75p. Most of the novel gene products were involved only in the carboxypeptidase Y pathway, whereas a few, including Mon1p, Mon2p, Vps61p, and Vps67p, appeared to be involved in both the carboxypeptidase Y and alkaline phosphatase pathways. Mutants lacking some of the novel gene products, including Arp5p, Arp6p, Vps64p, and Vps67p, were severely defective in secretion of mature ?-factor. Others, such as Vps61p, Vps64p, and Vps67p, displayed defects in the actin cytoskeleton at 30°C. The identification and phenotypic characterization of these novel mutants provide new insights into the mechanisms of vacuolar protein sorting, most notably the probable involvement of the actin cytoskeleton in this process. PMID:12134085

Bonangelino, Cecilia J.; Chavez, Edna M.; Bonifacino, Juan S.

2002-01-01

298

Interactions between Torulaspora delbrueckii and Saccharomyces cerevisiae in wine fermentation: influence of inoculation and nitrogen content.  

PubMed

Alcoholic fermentation by an oenological strain of Torulaspora delbrueckii in association with an oenological strain of Saccharomyces cerevisiae was studied in mixed and sequential cultures. Experiments were performed in a synthetic grape must medium in a membrane bioreactor, a special tool designed to study indirect interactions between microorganisms. Results showed that the S. cerevisiae strain had a negative impact on the T. delbrueckii strain, leading to a viability decrease as soon as S. cerevisiae was inoculated. Even for high inoculation of T. delbrueckii (more than 20× S. cerevisiae) in mixed cultures, T. delbrueckii growth was inhibited. Substrate competition and cell-to-cell contact mechanism could be eliminated as explanations of the observed interaction, which was probably an inhibition by a metabolite produced by S. cerevisiae. S. cerevisiae should be inoculated 48 h after T. delbrueckii in order to ensure the growth of T. delbrueckii and consequently a decrease of volatile acidity and a higher isoamyl acetate production. In this case, in a medium with a high concentration of assimilable nitrogen (324 mg L(-1)), S. cerevisiae growth was not affected by T. delbrueckii. But in a sequential fermentation in a medium containing 176 mg L(-1) initial assimilable nitrogen, S. cerevisiae was not able to develop because of nitrogen exhaustion by T. delbrueckii growth during the first 48 h, leading to sluggish fermentation. PMID:24500666

Taillandier, Patricia; Lai, Quoc Phong; Julien-Ortiz, Anne; Brandam, Cédric

2014-07-01

299

Toxicity of Nalidixic Acid on Candida albicans, Saccharomyces cerevisiae, and Kluyveromyces lactis  

PubMed Central

The antibacterial drug nalidixic acid (Nal) can suppress the growth of Candida albicans at levels of the drug normally found in urine. Growth suppression increases as drug levels are increased, and Nal also causes a similar proportional inhibition of the synthesis of all cellular macromolecules. However, growth temperature (25 versus 37 C) and the divalent cations Mg2+ and Mn2+ can increase C. albicans resistance to Nal. Also, nitrogen depletion of Candida shows that Nal-treated and untreated cells exhibit no difference in leucine uptake during readaptation to nitrogen. In Nal-treated, nitrogen-starved cells, ribonucleic acid and deoxyribonucleic acid (DNA) biosynthesis are less affected than in unstarved Nal-treated cells, but of the two nucleic acids DNA synthesis is the most affected. Nal-resistant strains of C. albicans exhibit a slight toxicity for macromolecular synthesis. Nal treatment of a synchronized population of Saccharomyces cerevisiae results in an increase in the culture mean doubling time of, at most, 20%, but Nal causes the loss of synchronous cell division. With a synchronized population of Kluyveromyces lactis, Nal causes an increase in the mean doubling time of upwards of 300%, with synchrony of cell division being maintained. It is known that S. cerevisiae asynchronously synthesizes mitochondrial DNA during the cell cycle, whereas with K. lactis it is synchronous. Thus, with C. albicans Nal toxicity is dependent both on the dose and the physiological state of the cell. Furthermore, Nal inhibits growth of yeast with synchronous mitochondrial DNA synthesis more adversely than yeast with asynchronous mitochondrial DNA synthesis. PMID:769680

Sobieski, Rodney J.; Brewer, Alan R.

1976-01-01

300

Copyright 2002 by the Genetics Society of America The tRNA-Tyr Gene Family of Saccharomyces cerevisiae: Agents of Phenotypic  

E-print Network

derived Saccharomyces cerevisiae strain involving a cox15 ochre mutation, which acts as a reporter ], Saccharomyces cerevisiae is a particularly useful phism, antigenic variation, and phase variation) playsCopyright 2002 by the Genetics Society of America The tRNA-Tyr Gene Family of Saccharomyces

Sinha, Himanshu

301

Modeling disease-related proteins in Saccharomyces cerevisiae : insights into alpha-synuclein and TorsinA biology  

E-print Network

The yeast Saccharomyces cerevisiae has long been used to model complex cellular processes. As a eukaryote, much of its fundamental biology is conserved with higher organisms. As a single-celled, genetically tractable ...

Valastyan, Julie S. (Julie Suzanne)

2013-01-01

302

The Enigmatic Conservation of a Rap1 Binding Site in the Saccharomyces cerevisiae HMR-E Silencer  

E-print Network

Silencing at the HMR and HML loci in Saccharomyces cerevisiae requires recruitment of Sir proteins to the HML and HMR silencers. The silencers are regulatory sites flanking both loci and consisting of binding sites for the ...

Teytelman, Leonid

303

An improved map of conserved regulatory sites for Saccharomyces cerevisiae  

E-print Network

Background: The regulatory map of a genome consists of the binding sites for proteins that determine the transcription of nearby genes. An initial regulatory map for S. cerevisiae was recently published using six motif ...

Wang, Ting

304

Microbial Cells as Biosorbents for Heavy Metals: Accumulation of Uranium by Saccharomyces cerevisiae and Pseudomonas aeruginosa  

PubMed Central

Uranium accumulated extracellularly on the surfaces of Saccharomyces cerevisiae cells. The rate and extent of accumulation were subject to environmental parameters, such as pH, temperature, and interference by certain anions and cations. Uranium accumulation by Pseudomonas aeruginosa occurred intracellularly and was extremely rapid (<10 s), and no response to environmental parameters could be detected. Metabolism was not required for metal uptake by either organism. Cell-bound uranium reached a concentration of 10 to 15% of the dry cell weight, but only 32% of the S. cerevisiae cells and 44% of the P. aeruginosa cells within a given population possessed visible uranium deposits when examined by electron microscopy. Rates of uranium uptake by S. cerevisiae were increased by chemical pretreatment of the cells. Uranium could be removed chemically from S. cerevisiae cells, and the cells could then be reused as a biosorbent. Images PMID:16345691

Strandberg, Gerald W.; Shumate, Starling E.; Parrott, John R.

1981-01-01

305

Metabolic engineering of Saccharomyces cerevisiae to improve succinic acid production based on metabolic profiling.  

PubMed

We performed metabolic engineering on the budding yeast Saccharomyces cerevisiae for enhanced production of succinic acid. Aerobic succinic acid production in S. cerevisiae was achieved by disrupting the SDH1 and SDH2 genes, which encode the catalytic subunits of succinic acid dehydrogenase. Increased succinic acid production was achieved by eliminating the ethanol biosynthesis pathways. Metabolic profiling analysis revealed that succinic acid accumulated intracellularly following disruption of the SDH1 and SDH2 genes, which suggests that enhancing the export of intracellular succinic acid outside of cells increases succinic acid production in S. cerevisiae. The mae1 gene encoding the Schizosaccharomyces pombe malic acid transporter was introduced into S. cerevisiae, and as a result, succinic acid production was successfully improved. Metabolic profiling analysis is useful in producing chemicals for metabolic engineering of microorganisms. PMID:25036498

Ito, Yuma; Hirasawa, Takashi; Shimizu, Hiroshi

2014-01-01

306

Identification of New Genes Required for Meiotic Recombination in Saccharomyces Cerevisiae  

PubMed Central

Mutants defective in meiotic recombination were isolated from a disomic haploid strain of Saccharomyces cerevisiae by examining recombination within the leu2 and his4 heteroalleles located on chromosome III. The mutants were classified into two new complementation groups (MRE2 and MRE11) and eight previously identified groups, which include SPO11, HOP1, REC114, MRE4/MEK1 and genes in the RAD52 epistasis group. All of the mutants, in which the mutations in the new complementation groups are homozygous and diploid, can undergo premeiotic DNA synthesis and produce spores. The spores are, however, not viable. The mre2 and mre11 mutants produce viable spores in a spo13 background, in which meiosis I is bypassed, suggesting that these mutants are blocked at an early step in meiotic recombination. The mre2 mutant does not exhibit any unusual phenotype during mitosis and it is, thus, considered to have a mutation in a meiosis-specific gene. By contrast, the mre11 mutant is sensitive to damage to DNA by methyl methanesulfonate and exhibits a hyperrecombination phenotype in mitosis. Among six alleles of HOP1 that were isolated, an unusual pattern of intragenic complementation was observed. PMID:8417989

Ajimura, M.; Leem, S. H.; Ogawa, H.

1993-01-01

307

dUTPase activity is critical to maintain genetic stability in Saccharomyces cerevisiae  

PubMed Central

We identified a viable allele (dut1-1) of the DUT1 gene that encodes the dUTPase activity in Saccharomyces cerevisiae. The Dut1-1 protein possesses a single amino acid substitution (Gly82Ser) in a conserved motif nearby the active site and exhibits a greatly reduced dUTPase activity. The dut1-1 single mutant exhibits growth delay and cell cycle abnormalities and shows a strong spontaneous mutator phenotype. All phenotypes of the dut1-1 mutant are suppressed by the simultaneous inactivation of the uracil DNA N-glycosylase, Ung1. However, the ung1 dut1-1 double mutant accumulates uracil in its genomic DNA. The viability of the dut1-1 mutant is greatly impaired by the simultaneous inactivation of AP endonucleases. These data strongly suggest that the phenotypes of the dut1-1 mutant result from the incorporation of dUMPs into DNA subsequently converted into AP sites. The analysis of the dut1-1 strain mutation spectrum showed that cytosines are preferentially incorporated in front of AP sites in a Rev3-dependent manner during translesion synthesis. These results point to a critical role of the Dut1 protein in the maintenance of the genetic stability. Therefore, the normal cellular metabolism, and not only its byproducts, is an important source of endogenous DNA damage and genetic instability in eukaryotic cells. PMID:16617146

Guillet, Marie; Van Der Kemp, Patricia Auffret; Boiteux, Serge

2006-01-01

308

Performance evaluation of Pichia kluyveri, Kluyveromyces marxianus and Saccharomyces cerevisiae in industrial tequila fermentation.  

PubMed

Traditionally, industrial tequila production has used spontaneous fermentation or Saccharomyces cerevisiae yeast strains. Despite the potential of non-Saccharomyces strains for alcoholic fermentation, few studies have been performed at industrial level with these yeasts. Therefore, in this work, Agave tequilana juice was fermented at an industrial level using two non-Saccharomyces yeasts (Pichia kluyveri and Kluyveromyces marxianus) with fermentation efficiency higher than 85 %. Pichia kluyveri (GRO3) was more efficient for alcohol and ethyl lactate production than S. cerevisiae (AR5), while Kluyveromyces marxianus (GRO6) produced more isobutanol and ethyl-acetate than S. cerevisiae (AR5). The level of volatile compounds at the end of fermentation was compared with the tequila standard regulation. All volatile compounds were within the allowed range except for methanol, which was higher for S. cerevisiae (AR5) and K. marxianus (GRO6). The variations in methanol may have been caused by the Agave tequilana used for the tests, since this compound is not synthesized by these yeasts. PMID:23329062

Amaya-Delgado, L; Herrera-López, E J; Arrizon, Javier; Arellano-Plaza, M; Gschaedler, A

2013-05-01

309

Genetic and molecular mapping of the pma1 mutation conferring vanadate resistance to the plasma membrane ATPase from Saccharomyces cerevisiae  

Microsoft Academic Search

In the yeast Saccharomyces cerevisiae, the pma1 mutations confers vanadate-resistance to H+-ATPase activity when measured in isolated plasma membranes. In vivo, the growth of pma1 mutants is resistant to Dio-9, ethidium bromide and guanidine derivatives. This phenotype was used to man the pma1 mutation adjacent to LEU1 gene on chromosome VII. From a cosmid library of a wild-type Saccharomyces cerevisiae

Stanislaw Ulaszewski; Elisabetta Balzi; André Goffeau

1987-01-01

310

The SUP35 Omnipotent Suppressor Gene Is Involved in the Maintenance of the Non-Mendelian Determinant (psi') in the Yeast Saccharomyces cerevisiae  

Microsoft Academic Search

The SUP35 gene of yeast Saccharomyces cerevisiae encodes a 76.5-kD ribosome-associated protein (Sup35p), the Gterminal part of which exhibits a high degree of similarity to EF-la elongation factor, while its N-terminal region is unique. Mutations in or overexpression of the SUP35 gene can generate an omnipotent suppressor effect. In the present study the SUP35wild-type gene was replaced with deletion alleles

Michael D. Ter-Avanesyan; Adilya R. Dagkesamanskaya; Vitaly V. Kushnirov; Vladimir N. Smirnov

1994-01-01

311

Interactions between Lactobacillus kefiranofaciens and Saccharomyces cerevisiae in mixed culture for kefiran production.  

PubMed

Since a positive effect on the growth and kefiran production of Lactobacillus kefiranofaciens was observed in a mixed culture with Saccharomyces cerevisiae, the elucidation of the interactions between L. kefiranofaciens and S. cerevisiae may lead to higher productivity. Hence, the microbial interaction of each strain was investigated. Apart from the positive effect of a reduction in the amount of lactic acid by S. cerevisiae, a positive effect of S. cerevisiae on the growth and kefiran production of L. kefiranofaciens in a mixed culture was observed. Various experiments were carried out to study this effect. In this study, the observed increase in capsular kefiran in a mixed culture with inactivated S. cerevisiae correlated well to that in an anaerobic mixed culture. Differences in capsular kefiran production were observed for different initial S. cerevisiae concentrations under anaerobic conditions. From these fermentation results, it was concluded that the physical contact with S. cerevisiae mainly enhanced the capsular kefiran production of L. kefiranofaciens in a mixed culture. Therefore, in an anaerobic mixed culture, this direct contact resulted in higher capsular kefiran production than that in pure culture. PMID:16233522

Cheirsilp, Benjamas; Shoji, Hirofumi; Shimizu, Hiroshi; Shioya, Suteaki

2003-01-01

312

Fumaric Acid Production in Saccharomyces cerevisiae by In Silico Aided Metabolic Engineering  

PubMed Central

Fumaric acid (FA) is a promising biomass-derived building-block chemical. Bio-based FA production from renewable feedstock is a promising and sustainable alternative to petroleum-based chemical synthesis. Here we report on FA production by direct fermentation using metabolically engineered Saccharomyces cerevisiae with the aid of in silico analysis of a genome-scale metabolic model. First, FUM1 was selected as the target gene on the basis of extensive literature mining. Flux balance analysis (FBA) revealed that FUM1 deletion can lead to FA production and slightly lower growth of S. cerevisiae. The engineered S. cerevisiae strain obtained by deleting FUM1 can produce FA up to a concentration of 610±31 mg L–1 without any apparent change in growth in fed-batch culture. FT-IR and 1H and 13C NMR spectra confirmed that FA was synthesized by the engineered S. cerevisiae strain. FBA identified pyruvate carboxylase as one of the factors limiting higher FA production. When the RoPYC gene was introduced, S. cerevisiae produced 1134±48 mg L–1 FA. Furthermore, the final engineered S. cerevisiae strain was able to produce 1675±52 mg L–1 FA in batch culture when the SFC1 gene encoding a succinate–fumarate transporter was introduced. These results demonstrate that the model shows great predictive capability for metabolic engineering. Moreover, FA production in S. cerevisiae can be efficiently developed with the aid of in silico metabolic engineering. PMID:23300594

Xu, Guoqiang; Zou, Wei; Chen, Xiulai; Xu, Nan; Liu, Liming; Chen, Jian

2012-01-01

313

Mathematical model for the aerobic growth of saccharomyces cerevisiae with a saturated respiratory capacity  

SciTech Connect

A mathematical model for the aerobic growth of Saccharomyces cerevisiae in both batch and continuous culture is described. It was based on the experimental observation that the respiratory capacity of this organism may become saturated and exhibit a maximum specific oxygen uptake rate after suitable adaptation. This experimental observation led to the possibility that transport into and out of the mitochondrion was of major importance in the overall metabolism of S. cerevisiae and was subject to long-term adaptation. Consistent with this observation a distributed model was proposed which, as its basis, assumed the control of respiration and fermentation to be the result of saturation of respiration without any specific repression or inhibition of the uptake rates of other substrates. No other regulation of fermentation and respiration was assumed. The model provided a suitable structure allowing precise quantification of the changes in rate and stoichiometry of energy production. The model clearly indicated that growth under the wide range of experimental conditions reported could not be predicted using constant values for the maximum specific respiratory rate or constant values of Yatp (g biomass/mol ATP) and PO ratio of (mol ATP/atom oxygen). The causes of the variation in the respiratory rate were not determined and it was concluded that a more detailed analysis (reported subsequently) was required. The variation of Y atp and PO ratio with specific growth rate implied that the efficiency of ATP generation or ATP utilization decreased with increasing specific growth rate. It was concluded that it was not possible to quantify the individual effect of Yatp and PO ratio until independent means for their reliable estimation is available. (Refs. 84).

Barford, J.P.; Hall, R.J.

1981-08-01

314

Growth Temperature Exerts Differential Physiological and Transcriptional Responses in Laboratory and Wine Strains of Saccharomyces cerevisiae? †  

PubMed Central

Laboratory strains of Saccharomyces cerevisiae have been widely used as a model for studying eukaryotic cells and mapping the molecular mechanisms of many different human diseases. Industrial wine yeasts, on the other hand, have been selected on the basis of their adaptation to stringent environmental conditions and the organoleptic properties that they confer to wine. Here, we used a two-factor design to study the responses of a standard laboratory strain, CEN.PK113-7D, and an industrial wine yeast strain, EC1118, to growth temperatures of 15°C and 30°C in nitrogen-limited, anaerobic, steady-state chemostat cultures. Physiological characterization revealed that the growth temperature strongly impacted the biomass yield of both strains. Moreover, we found that the wine yeast was better adapted to mobilizing resources for biomass production and that the laboratory yeast exhibited higher fermentation rates. To elucidate mechanistic differences controlling the growth temperature response and underlying adaptive mechanisms between the strains, DNA microarrays and targeted metabolome analysis were used. We identified 1,007 temperature-dependent genes and 473 strain-dependent genes. The transcriptional response was used to identify highly correlated gene expression subnetworks within yeast metabolism. We showed that temperature differences most strongly affect nitrogen metabolism and the heat shock response. A lack of stress response element-mediated gene induction, coupled with reduced trehalose levels, indicated that there was a decreased general stress response at 15°C compared to that at 30°C. Differential responses among strains were centered on sugar uptake, nitrogen metabolism, and expression of genes related to organoleptic properties. Our study provides global insight into how growth temperature affects differential physiological and transcriptional responses in laboratory and wine strains of S. cerevisiae. PMID:18723660

Pizarro, Francisco J.; Jewett, Michael C.; Nielsen, Jens; Agosin, Eduardo

2008-01-01

315

Growth temperature exerts differential physiological and transcriptional responses in laboratory and wine strains of Saccharomyces cerevisiae.  

PubMed

Laboratory strains of Saccharomyces cerevisiae have been widely used as a model for studying eukaryotic cells and mapping the molecular mechanisms of many different human diseases. Industrial wine yeasts, on the other hand, have been selected on the basis of their adaptation to stringent environmental conditions and the organoleptic properties that they confer to wine. Here, we used a two-factor design to study the responses of a standard laboratory strain, CEN.PK113-7D, and an industrial wine yeast strain, EC1118, to growth temperatures of 15 degrees C and 30 degrees C in nitrogen-limited, anaerobic, steady-state chemostat cultures. Physiological characterization revealed that the growth temperature strongly impacted the biomass yield of both strains. Moreover, we found that the wine yeast was better adapted to mobilizing resources for biomass production and that the laboratory yeast exhibited higher fermentation rates. To elucidate mechanistic differences controlling the growth temperature response and underlying adaptive mechanisms between the strains, DNA microarrays and targeted metabolome analysis were used. We identified 1,007 temperature-dependent genes and 473 strain-dependent genes. The transcriptional response was used to identify highly correlated gene expression subnetworks within yeast metabolism. We showed that temperature differences most strongly affect nitrogen metabolism and the heat shock response. A lack of stress response element-mediated gene induction, coupled with reduced trehalose levels, indicated that there was a decreased general stress response at 15 degrees C compared to that at 30 degrees C. Differential responses among strains were centered on sugar uptake, nitrogen metabolism, and expression of genes related to organoleptic properties. Our study provides global insight into how growth temperature affects differential physiological and transcriptional responses in laboratory and wine strains of S. cerevisiae. PMID:18723660

Pizarro, Francisco J; Jewett, Michael C; Nielsen, Jens; Agosin, Eduardo

2008-10-01

316

Development of a cellulolytic Saccharomyces cerevisiae strain with enhanced cellobiohydrolase activity.  

PubMed

Consolidated bioprocessing (CBP) is a promising technology for lignocellulosic ethanol production, and the key is the engineering of a microorganism that can efficiently utilize cellulose. Development of Saccharomyces cerevisiae for CBP requires high level expression of cellulases, particularly cellobiohydrolases (CBH). In this study, to construct a CBP-enabling yeast with enhanced CBH activity, three cassettes containing constitutively expressed CBH-encoding genes (cbh1 from Aspergillus aculeatus, cbh1 and cbh2 from Trichoderma reesei) were constructed. T. reesei eg2, A. aculeatus bgl1, and the three CBH-encoding genes were then sequentially integrated into the S. cerevisiae W303-1A chromosome via ?-sequence-mediated integration. The resultant strains W1, W2, and W3, expressing uni-, bi-, and trifunctional cellulases, respectively, exhibited corresponding cellulase activities. Furthermore, both the activities and glucose producing activity ascended. The growth test on cellulose containing plates indicated that CBH was a necessary component for successful utilization of crystalline cellulose. The three recombinant strains and the control strains W303-1A and AADY were evaluated in acid- and alkali-pretreated corncob containing media with 5 FPU exogenous cellulase/g biomass loading. The highest ethanol titer (g/l) within 7 days was 5.92 ± 0.51, 18.60 ± 0.81, 28.20 ± 0.84, 1.40 ± 0.12, and 2.12 ± 0.35, respectively. Compared with the control strains, W3 efficiently fermented pretreated corncob to ethanol. To our knowledge, this is the first study aimed at creating cellulolytic yeast with enhanced CBH activity by integrating three types of CBH-encoding gene with a strong constitutive promoter Ptpi. PMID:25164958

Hong, Jiefang; Yang, Huajun; Zhang, Kun; Liu, Cheng; Zou, Shaolan; Zhang, Minhua

2014-11-01

317

Production of Extracellular and Total Invertase by Candida utilis, Saccharomyces cerevisiae, and Other Yeasts  

PubMed Central

Some strains of Candida utilis produce exceptionally large amounts of extracellular and total invertase. Strain Y-900 of C. utilis produces high yields whether the carbon source is sucrose, glucose, maltose, or xylose and still higher yields with lactic acid, glycerol, and ethyl alcohol. Approximately 20 to 30% of the total invertase of C. utilis is extracellular. Strains of Saccharomyces cerevisiae and Saccharomyces carlsbergensis are generally inferior to C. utilis in production of extracellular and total invertase, the difference being accentuated in shaken cultures. The industrial yeasts are generally superior in invertase production to the other yeasts included in the survey. PMID:13725351

Dworschack, Robert G.; Wickerham, Lynferd J.

1961-01-01

318

A genetic analysis of glucoamylase activity in the diastatic yeast Saccharomyces cerevisiae NCYC 625.  

PubMed

The wild diastatic yeast Saccharomyces cerevisiae NCYC 625 has been shown to be homozygous for the glucoamylase-specifying gene STA2. spoII-1-mapping has positioned STA2 on chromosome II. Expression of STA2 is suppressed in some but not all diploids capable of sporulation, and is also inhibited by unlinked nuclear suppressor genes (SGL) found in some S. cerevisiae tester strains. EMS-induced glucoamylase-negative mutants often contain STA2-suppressor mutations. Depending on the allelic status of GEP1, a nuclear gene which also appears able to antagonise SGL-mediated suppression, STA2 expression can be blocked in petite mutants. PMID:2111230

Patel, D; Evans, I H; Bevan, E A

1990-04-01

319

Unequal division in Saccharomyces cerevisiae and its implications for the control of cell division  

Microsoft Academic Search

ABSTRACT The budding yeast, Saccharomyces cerevisiae, was grown exponentially at differ- ent,rates,in the,presence,of growth,rate-limiting concentrations,of a protein synthesis inhibitor, cycloheximide. The volumes of the parent cell and the bud were,determined,as were,the intervals of the cell cycle devoted,to the unbudded and,budded,periods. We,found,that S. cerevisiae cells divide,unequally.,The daughter,cell (the cell produced,at division,by the,bud,of the previous,cycle) is smaller,and,has a longer,subsequent,cell cycle than,the parent,cell

Leland H. Hartwell; Michael W. Unger

1977-01-01

320

Oxygen dependence of metabolic fluxes and energy generation of Saccharomyces cerevisiae CEN.PK113-1A  

Microsoft Academic Search

BACKGROUND: The yeast Saccharomyces cerevisiae is able to adjust to external oxygen availability by utilizing both respirative and fermentative metabolic modes. Adjusting the metabolic mode involves alteration of the intracellular metabolic fluxes that are determined by the cell's multilevel regulatory network. Oxygen is a major determinant of the physiology of S. cerevisiae but understanding of the oxygen dependence of intracellular

Paula Jouhten; Eija Rintala; Anne Huuskonen; Anu Tamminen; Mervi Toivari; Marilyn Wiebe; Laura Ruohonen; Merja Penttilä; Hannu Maaheimo

2008-01-01

321

Comparison of Pb2 accumulation characteristics between live and dead cells of Saccharomyces cerevisiae and Aureobasidium pullulans  

Microsoft Academic Search

Pb2+ accumulation processes between live and dead cells of Saccharomyces cerevisiae and Aureobasidium pullulans are different. In the case of S. cerevisiae, the Pb2+ accumulation capacity of the live cells was higher than that of the dead cells but they showed reversed initial Pb2+ accumulation rates. On the contrary, A. pullulans used a different process due to the existence of

Jung Ho Suh; Jong Won Yun; Dong Seog Kim

1998-01-01

322

Antibody to selected strains of Saccharomyces cerevisiae (baker's and brewer's yeast) and Candida albicans in Crohn's disease  

Microsoft Academic Search

IgG serum antibody was measured by ELISA in patients with Crohn's disease (15), ulcerative colitis (15), and in normal controls (15) to 12 strains of Saccharomyces cerevisiae (baker's and brewer's yeast) and to the two major serotypes of the commensal yeast Candida albicans. Antibody to 11 of the 12 strains of S cerevisiae was raised in patients with Crohn's disease

H McKenzie; J Main; C R Pennington; D Parratt

1990-01-01

323

Copyright 2002 by the Genetics Society of America Spt3 Plays Opposite Roles in Filamentous Growth in Saccharomyces cerevisiae  

E-print Network

in Saccharomyces cerevisiae and Candida albicans and Is Required for C. albicans Virulence Lisa Laprade,* Victor L's role in filamentous growth to the pathogenic yeast Candida albicans, we have identified the C growth in S. cerevisiae and Candida albicans. ment of TATA-binding protein (TBP) to particular pro- S

Winston, Fred

324

Biodegradation of crude oil by Saccharomyces cerevisiae isolated from fermented zobo (locally fermented beverage in Nigeria).  

PubMed

The increase in demand for crude oil as a source of energy and as a primary raw material for industries has resulted in an increase in its production, transportation and refining, which in turn has resulted in gross pollution of the environment. In this study, Saccharomyces cerevisiae isolated from a commercially prepared local fermented beverage 'zobo' (prepared from Hibiscus flower) was tested to determine its potential to degrade crude oil for a period of 28 days under aerobic condition. The percentage of oil biodegradation was determined using weight loss method and gas chromatography mass spectroscopy (GC/MS) of the residual crude oil after 28 days. At the end of 28 days 49.29% crude oil degradation was recorded. The result suggests the potential of Saccharomyces cerevisiae for bioremediation of oil polluted sites. PMID:24517030

Abioye, O P; Akinsola, R O; Aransiola, S A; Damisa, D

2013-12-15

325

Crystallization and Preliminary X-ray Diffraction Analysis of motif N from Saccharomyces cerevisiae Dbf4  

SciTech Connect

The Cdc7-Dbf4 complex plays an instrumental role in the initiation of DNA replication and is a target of replication-checkpoint responses in Saccharomyces cerevisiae. Cdc7 is a conserved serine/threonine kinase whose activity depends on association with its regulatory subunit, Dbf4. A conserved sequence near the N-terminus of Dbf4 (motif N) is necessary for the interaction of Cdc7-Dbf4 with the checkpoint kinase Rad53. To understand the role of the Cdc7-Dbf4 complex in checkpoint responses, a fragment of Saccharomyces cerevisiae Dbf4 encompassing motif N was isolated, overproduced and crystallized. A complete native data set was collected at 100 K from crystals that diffracted X-rays to 2.75 {angstrom} resolution and structure determination is currently under way.

Matthews, L.; Duong, A; Prasad, A; Duncker, B; Guarne, A

2009-01-01

326

Selection of optimum expression system for production of kringle fragment of human apolipoprotein(a) in Saccharomyces cerevisiae  

Microsoft Academic Search

RecombinantSaccharomyces cerevisiae expression systems were developed to produce a novel human anti-angiogenic protein called LK8, an 86 amino-acid kringle fragment\\u000a protein with three disulfide linkages. Galactose-inducible LK8 expression plasmid was constructed, and LK8 production levels\\u000a by fourS. cerevisiae strains were compared in order to select an optimal host strain.S. cerevisiae 2805 was the most efficient among the strains tested. Elevating

Kwang-Hyun Cha; Myoung-Dong Kim; Tae-Hee Lee; Hyung-Kweon Lim; Kyung-Hwan Jung; Jin-Ho Seo

2004-01-01

327

Tomato QM-Like Protein Protects Saccharomyces cerevisiae Cells against Oxidative Stress by Regulating Intracellular Proline Levels  

Microsoft Academic Search

Exogenous proline can protect cells of Saccharomyces cerevisiae from oxidative stress. We altered intracel- lular proline levels by overexpressing the proline dehydrogenase gene (PUT1 )o fS. cerevisiae. Put1p performs the first enzymatic step of proline degradation in S. cerevisiae. Overexpression of Put1p results in low proline levels and hypersensitivity to oxidants, such as hydrogen peroxide and paraquat. A put1-disrupted yeast

Changbin Chen; Srimevan Wanduragala; Donald F. Becker; Martin B. Dickman

2006-01-01

328

Design of a minimal silencer for the silent mating-type locus HML of Saccharomyces cerevisiae.  

PubMed

The silent mating-type loci HML and HMR of Saccharomyces cerevisiae contain mating-type information that is permanently repressed. This silencing is mediated by flanking sequence elements, the E- and I-silencers. They contain combinations of binding sites for the proteins Rap1, Abf1 and Sum1 as well as for the origin recognition complex (ORC). Together, they recruit other silencing factors, foremost the repressive Sir2/Sir3/Sir4 complex, to establish heterochromatin-like structures at the HM loci. However, the HM silencers exhibit considerable functional redundancy, which has hampered the identification of further silencing factors. In this study, we constructed a synthetic HML-E silencer (HML-SS ?I) that lacked this redundancy. It consisted solely of Rap1 and ORC-binding sites and the D2 element, a Sum1-binding site. All three elements were crucial for minimal HML silencing, and mutations in these elements led to a loss of Sir3 recruitment. The silencer was sensitive to a mutation in RAP1, rap1-12, but less sensitive to orc mutations or sum1?. Moreover, deletions of SIR1 and DOT1 lead to complete derepression of the HML-SS ?I silencer. This fully functional, minimal HML-E silencer will therefore be useful to identify novel factors involved in HML silencing. PMID:20699276

Weber, Jan M; Ehrenhofer-Murray, Ann E

2010-12-01

329

Replication protein A is required for meiotic recombination in Saccharomyces cerevisiae.  

PubMed Central

In Saccharomyces cerevisiae, meiotic recombination is initiated by transient DNA double-stranded breaks (DSBs). These DSBs undergo a 5' --> 3' resection to produce 3' single-stranded DNA ends that serve to channel DSBs into the RAD52 recombinational repair pathway. In vitro studies strongly suggest that several proteins of this pathway--Rad51, Rad52, Rad54, Rad55, Rad57, and replication protein A (RPA)--play a role in the strand exchange reaction. Here, we report a study of the meiotic phenotypes conferred by two missense mutations affecting the largest subunit of RPA, which are localized in the protein interaction domain (rfa1-t11) and in the DNA-binding domain (rfa1-t48). We find that both mutant diploids exhibit reduced sporulation efficiency, very poor spore viability, and a 10- to 100-fold decrease in meiotic recombination. Physical analyses indicate that both mutants form normal levels of meiosis-specific DSBs and that the broken ends are processed into 3'-OH single-stranded tails, indicating that the RPA complex present in these rfa1 mutants is functional in the initial steps of meiotic recombination. However, the 5' ends of the broken fragments undergo extensive resection, similar to what is observed in rad51, rad52, rad55, and rad57 mutants, indicating that these RPA mutants are defective in the repair of the Spo11-dependent DSBs that initiate homologous recombination during meiosis. PMID:12072452

Soustelle, Christine; Vedel, Michèle; Kolodner, Richard; Nicolas, Alain

2002-01-01

330

Cardiolipin and Mitochondrial Phosphatidylethanolamine Have Overlapping Functions in Mitochondrial Fusion in Saccharomyces cerevisiae*  

PubMed Central

The two non-bilayer forming mitochondrial phospholipids cardiolipin (CL) and phosphatidylethanolamine (PE) play crucial roles in maintaining mitochondrial morphology. We have shown previously that CL and PE have overlapping functions, and the loss of both is synthetically lethal. Because the lack of CL does not lead to defects in the mitochondrial network in Saccharomyces cerevisiae, we hypothesized that PE may compensate for CL in the maintenance of mitochondrial tubular morphology and fusion. To test this hypothesis, we constructed a conditional mutant crd1?psd1? containing null alleles of CRD1 (CL synthase) and PSD1 (mitochondrial phosphatidylserine decarboxylase), in which the wild type CRD1 gene is expressed on a plasmid under control of the TETOFF promoter. In the presence of tetracycline, the mutant exhibited highly fragmented mitochondria, loss of mitochondrial DNA, and reduced membrane potential, characteristic of fusion mutants. Deletion of DNM1, required for mitochondrial fission, restored the tubular mitochondrial morphology. Loss of CL and mitochondrial PE led to reduced levels of small and large isoforms of the fusion protein Mgm1p, possibly accounting for the fusion defect. Taken together, these data demonstrate for the first time in vivo that CL and mitochondrial PE are required to maintain tubular mitochondrial morphology and have overlapping functions in mitochondrial fusion. PMID:22433850

Joshi, Amit S.; Thompson, Morgan N.; Fei, Naomi; Huttemann, Maik; Greenberg, Miriam L.

2012-01-01

331

Strain-specific nuclear genetic background differentially affects mitochondria-related phenotypes in Saccharomyces cerevisiae.  

PubMed

In the course of our studies on mitochondrial defects, we have observed important phenotypic variations in Saccharomyces cerevisiae strains suggesting that a better characterization of the genetic variability will be essential to define the relationship between the mitochondrial efficiency and the presence of different nuclear backgrounds. In this manuscript, we have extended the study of such relations by comparing phenotypic assays related to mitochondrial functions of three wild-type laboratory strains. In addition to the phenotypic variability among the wild-type strains, important differences have been observed among strains bearing identical mitochondrial tRNA mutations that could be related only to the different nuclear background of the cells. Results showed that strains exhibited an intrinsic variability in the severity of the effects of the mitochondrial mutations and that specific strains might be used preferentially to evaluate the phenotypic effect of mitochondrial mutations on carbon metabolism, stress responses, and mitochondrial DNA stability. In particular, while W303-1B and MCC123 strains should be used to study the effect of severe mitochondrial tRNA mutations, D273-10B/A1 strain is rather suitable for studying the effects of milder mutations. PMID:24700775

Montanari, Arianna; Francisci, Silvia; Fazzi D'Orsi, Mario; Bianchi, Michele Maria

2014-06-01

332

Enhancement of ethanol fermentation in Saccharomyces cerevisiae sake yeast by disrupting mitophagy function.  

PubMed

Saccharomyces cerevisiae sake yeast strain Kyokai no. 7 has one of the highest fermentation rates among brewery yeasts used worldwide; therefore, it is assumed that it is not possible to enhance its fermentation rate. However, in this study, we found that fermentation by sake yeast can be enhanced by inhibiting mitophagy. We observed mitophagy in wild-type sake yeast during the brewing of Ginjo sake, but not when the mitophagy gene (ATG32) was disrupted. During sake brewing, the maximum rate of CO2 production and final ethanol concentration generated by the atg32? laboratory yeast mutant were 7.50% and 2.12% higher than those of the parent strain, respectively. This mutant exhibited an improved fermentation profile when cultured under limiting nutrient concentrations such as those used during Ginjo sake brewing as well as in minimal synthetic medium. The mutant produced ethanol at a concentration that was 2.76% higher than the parent strain, which has significant implications for industrial bioethanol production. The ethanol yield of the atg32? mutant was increased, and its biomass yield was decreased relative to the parent sake yeast strain, indicating that the atg32? mutant has acquired a high fermentation capability at the cost of decreasing biomass. Because natural biomass resources often lack sufficient nutrient levels for optimal fermentation, mitophagy may serve as an important target for improving the fermentative capacity of brewery yeasts. PMID:24271183

Shiroma, Shodai; Jayakody, Lahiru Niroshan; Horie, Kenta; Okamoto, Koji; Kitagaki, Hiroshi

2014-02-01

333

Quantitative study of interactions between Saccharomyces cerevisiae and Oenococcus oeni strains.  

PubMed

This study examines the interactions that occur between Saccharomyces cerevisiae and Oenococcus oeni strains during the process of winemaking. Various yeast/bacteria pairs were studied by applying a sequential fermentation strategy which simulated the natural winemaking process. First, four yeast strains were tested in the presence of one bacterial strain leading to the inhibition of the bacterial component. The extent of inhibition varied widely from one pair to another and closely depended on the specific yeast strain chosen. Inhibition was correlated to weak bacterial growth rather than a reduction in the bacterial malolactic activity. Three of the four yeast strains were then grown with another bacteria strain. Contrary to the first results, this led to the bacterial stimulation, thus highlighting the importance of the bacteria strain. The biochemical profile of the four yeast fermented media exhibited slight variations in ethanol, SO(2) and fatty acids produced as well as assimilable consumed nitrogen. These parameters were not the only factors responsible for the malolactic fermentation inhibition observed with the first bacteria strain. The stimulation of the second has not been reported before in such conditions and remains unexplained. PMID:18317828

Nehme, Nancy; Mathieu, Florence; Taillandier, Patricia

2008-07-01

334

Investigation of the Highly Active Manganese Superoxide Dismutase from Saccharomyces cerevisiae  

SciTech Connect

Manganese superoxide dismutase (MnSOD) from different species differs in its efficiency in removing high concentrations of superoxide (O{sub 2}{sup -}), due to different levels of product inhibition. Human MnSOD exhibits a substantially higher level of product inhibition than the MnSODs from bacteria. In order to investigate the mechanism of product inhibition and whether it is a feature common to eukaryotic MnSODs, we purified MnSOD from Saccharomyces cerevisiae (ScMnSOD). It was a tetramer with 0.6 equiv of Mn per monomer. The catalytic activity of ScMnSOD was investigated by pulse radiolysis and compared with human and two bacterial (Escherichia coli and Deinococcus radiodurans) MnSODs. To our surprise, ScMnSOD most efficiently facilitates removal of high concentrations of O{sub 2}{sup -} among these MnSODs. The gating value k{sub 2}/k{sub 3} that characterizes the level of product inhibition scales as ScMnSOD > D. radiodurans MnSOD > E. coli MnSOD > human MnSOD. While most MnSODs rest as the oxidized form, ScMnSOD was isolated in the Mn{sup 2+} oxidation state as revealed by its optical and electron paramagnetic resonance spectra. This finding poses the possibility of elucidating the origin of product inhibition by comparing human MnSOD with ScMnSOD.

Cabelli, D.E.; Barnese, K.; Sheng, Y.; Stich, T.A.; Gralla, E.B.; Britt, R.D.; Valentine, J.S.

2010-09-15

335

Pronounced and Extensive Microtubule Defects in a Saccharomyces cerevisiae DIS3 Mutant  

PubMed Central

Subunits of the RNA processing exosome assemble into structurally distinct protein complexes that function in disparate cellular compartments and RNA metabolic pathways. Here, in a genetic, cell biological, and transcriptomic analysis, we examine the role of Dis3 – an essential polypeptide with endo- and 3’ to 5’ exo-ribonuclease activity – in cell cycle progression. We present several lines of evidence that perturbation of DIS3 affects microtubule (MT) localization and structure in Saccharomyces cerevisiae. Cells with a DIS3 mutant: (i) accumulate anaphase and pre-anaphase mitotic spindles; (ii) exhibit spindles that are mis-oriented and displaced from the bud neck; (iii) harbor elongated spindle-associated astral MTs; (iv) have an increased G1 astral MT length and number; and (v) are hypersensitive to MT poisons. Mutations in the core exosome genes RRP4 and MTR3 and the exosome cofactor gene MTR4 – but not other exosome subunit gene mutants – also elicit MT phenotypes. RNA deep sequencing analysis (RNA-seq) shows broad changes in the levels of cell cycle- and MT-related transcripts in mutant strains. Collectively, the data presented in this study suggests an evolutionarily conserved role for Dis3 in linking RNA metabolism, MTs, and cell cycle progression. PMID:21919057

Smith, Sarah B.; Kiss, Daniel L.; Turk, Edward; Tartakoff, Alan M.; Andrulis, Erik D.

2012-01-01

336

Role of DNA Replication Proteins in Double-Strand Break-Induced Recombination in Saccharomyces cerevisiae  

Microsoft Academic Search

Mitotic double-strand break (DSB)-induced gene conversion involves new DNA synthesis. We have analyzed the requirement of several essential replication components, the Mcm proteins, Cdc45p, and DNA ligase I, in the DNA synthesis of Saccharomyces cerevisiae MAT switching. In an mcm7-td (temperature-inducible degron) mutant, MAT switching occurred normally when Mcm7p was degraded below the level of detection, suggesting the lack of

Xuan Wang; Grzegorz Ira; JoseAntonio Tercero; Allyson M. Holmes; John F. X. Diffley; James E. Haber

2004-01-01

337

Fractionation of phenolic compounds extracted from propolis and their activity in the yeast Saccharomyces cerevisiae.  

PubMed

We have here investigated the activities of Slovenian propolis extracts in the yeast Saccharomyces cerevisiae, and identified the phenolic compounds that appear to contribute to these activities. We correlated changes in intracellular oxidation and cellular metabolic energy in these yeasts with the individual fractions of the propolis extracts obtained following solid-phase extraction. The most effective fraction was further investigated according to its phenolic compounds. PMID:23409133

Petelinc, Tanja; Polak, Tomaž; Demšar, Lea; Jamnik, Polona

2013-01-01

338

Mechanism of the aromatic aminotransferase encoded by the Aro8 gene from Saccharomyces cerevisiae  

Microsoft Academic Search

The amino acid l-lysine is synthesized in Saccharomyces cerevisiae via the ?-aminoadipate pathway. An as yet unidentified PLP-containing aminotransferase is thought to catalyze the formation of ?-aminoadipate from ?-ketoadipate in the l-lysine biosynthetic pathway that could be the yeast Aro8 gene product. A screen of several different amino acids and keto-acids showed that the enzyme uses l-tyrosine, l-phenylalanine, ?-ketoadipate, and

William E. Karsten; Zoraya L. Reyes; Kostyantyn D. Bobyk; Paul F. Cook; Lilian Chooback

339

Cellular localization of human p53 expressed in the yeast Saccharomyces cerevisiae : effect of NLSI deletion  

Microsoft Academic Search

The tumor suppressor p53 plays a central role in the regulation of cellular growth and apoptosis. In Saccharomyces cerevisiae, over-expression of the human wtp53 leads to growth inhibition and cell death on minimal medium. In the present work, we\\u000a showed that deletion of the nuclear localization signal (NLSI) of p53 restores the yeast growth. In this heterologous context,\\u000a the level

Salma Abdelmoula-Souissi; Agnès Delahodde; Monique Bolotin-Fukuhara; Ali Gargouri; Raja Mokdad-Gargouri

2011-01-01

340

Chemosensitization of Fluconazole Resistance in Saccharomyces cerevisiae and Pathogenic Fungi by a D-Octapeptide Derivative  

Microsoft Academic Search

Hyperexpression of the Saccharomyces cerevisiae multidrug ATP-binding cassette (ABC) transporter Pdr5p was driven by the pdr1-3 mutation in the Pdr1p transcriptional regulator in a strain (AD\\/PDR5) with deletions of five other ABC-type multidrug efflux pumps. The strain had high-level fluconazole (FLC) resis- tance (MIC, 600 gm l1), and plasma membrane fractions showed oligomycin-sensitive ATPase activity up to fivefold higher than

K. Niimi; D. R. K. Harding; R. Parshot; A. King; D. J. Lun; A. Decottignies; M. Niimi; S. Lin; R. D. Cannon; A. Goffeau; B. C. Monk

2004-01-01

341

Specificity of mutations induced by carbon ions in budding yeast Saccharomyces cerevisiae  

Microsoft Academic Search

To investigate the nature of mutations induced by accelerated ions in eukaryotic cells, the effects of carbon-ion irradiation were compared with those of ?-ray irradiation in the budding yeast Saccharomyces cerevisiae.The mutational effect and specificity of carbon-ion beams were studied in the URA3 gene of the yeast. Our experiments showed that the carbon ions generated more than 10 times the

Youichirou Matuo; Shigehiro Nishijima; Yoshihiro Hase; Ayako Sakamoto; Atsushi Tanaka; Kikuo Shimizu

2006-01-01

342

Mutational spectrum induced in Saccharomyces cerevisiae by the carcinogen N -2-acetylaminofluorene  

Microsoft Academic Search

The spectrum of mutations induced by the carcinogen N-2-acetylaminofluorene (AAF) was analysed in Saccharomyces cerevisiae using a forward mutation assay, namely the inactivation of the URA3 gene. The URA3 gene, carried on a yeast\\/bacterial shuttle vector, was randomly modified in vitro using N-acetoxy-N-2-acetylaminofluorene (N-AcO-AAF) as a model reactive metabolite of the carcinogen AAF. The binding spectrum of AAF to the

Anne Roy; Robert P. P. Fuchs

1994-01-01

343

Suppressors of the temperature sensitivity of DNA polymerase ? mutations in Saccharomyces cerevisiae  

Microsoft Academic Search

We have isolated two high copy, allele-specific suppressors of the temperature sensitivity of mutations in POL1, the gene that encodes the catalytic subunit of DNA polymerase ? in the yeast Saccharomyces cerevisiae. Both genes, PSP1 and PSP2, also partially suppressed a mutation in POL3 which encodes DNA polymerase ?, and both also affected a mutation in CDC6, which acts in

T. Formosa; T. Nittis

1998-01-01

344

Mutagenic Inverted Repeats Assisted Genome Engineering (MIRAGE) in Saccharomyces cerevisiae: deletion of gal7.  

PubMed

MIRAGE is a unique in vivo genome editing technique that exploits the inherent instability of inverted repeats (palindromes) in the Saccharomyces cerevisiae chromosome. As a technique able to quickly create deletions as well as precise point mutations, it is valuable in applications that require creation of designer strains of this yeast. In particular, it has various potential applications in metabolic engineering, systems biology, synthetic biology, and molecular genetics. PMID:22144353

Nair, Nikhil U; Zhao, Huimin

2012-01-01

345

Positive and Negative Autoregulation of REB1 Transcription in Saccharomyces cerevisiae  

Microsoft Academic Search

Reb1p is a DNA binding protein of Saccharomyces cerevisiae that has been implicated in the activation of transcription by polymerase (Pol) II, in the termination of transcription by Pol I, and in the organization of nucleosomes. Studies of the transcriptional control of the REB1 gene have led us to identify three Reb1p binding sites in the 5* region of the

C. WANG; JONATHAN R. WARNER

1998-01-01

346

Complex transcriptional circuitry at the G1\\/S transition in Saccharomyces cerevisiae  

Microsoft Academic Search

In the yeast Saccharomyces cerevisiae, SBF (Swi4-Swi6 cell cycle box binding factor) and MBF (MluI binding factor) are the major transcription factors regulating the START of the cell cycle, a time just before DNA replication, bud growth initiation, and spindle pole body (SPB) duplication. These two factors bind to the promoters of 235 genes, but bind less than a quarter

Christine E. Horak; Nicholas M. Luscombe; Jiang Qian; Paul Bertone; Stacy Piccirrillo; Mark Gerstein; Michael Snyder

2002-01-01

347

Assembly of bacteriophage Q? virus-like particles in yeast Saccharomyces cerevisiae and Pichia pastoris  

Microsoft Academic Search

Recombinant bacteriophage Q? coat protein (CP), which has been proposed as a promising carrier of foreign epitopes via their incorporation either by gene engineering techniques or by chemical coupling, efficiently self-assembles into virus-like particles (VLPs) when expressed in Escherichia coli. Here, we demonstrate expression and self-assembly of Q? CP in yeast Saccharomyces cerevisiae and Pichia pastoris. Production reached 3–4mg\\/1g of

Janis Freivalds; Andris Dislers; Velta Ose; Dace Skrastina; Indulis Cielens; Paul Pumpens; Kestutis Sasnauskas; Andris Kazaks

2006-01-01

348

Manipulation of intracellular magnesium levels in Saccharomyces cerevisiae with deletion of magnesium transporters  

Microsoft Academic Search

Magnesium is an important divalent ion for organisms. There have been a number of studies in vitro suggesting that magnesium\\u000a affects enzyme activity. Surprisingly, there have been few studies to determine the cellular mechanism for magnesium regulation.\\u000a We wished to determine if magnesium levels could be regulated in vivo. It is known that Saccharomyces cerevisiae has two magnesium transporters (ALR1

Bernardo M. T. da Costa; Katrina Cornish; Jay D. Keasling

2007-01-01

349

New amylolytic yeast strains for starch and dextrin fermentation. [Schwanniomyces alluvius, Saccharomyces cerevisiae var. diastaticus  

SciTech Connect

Yeast strains capable of fermenting starch and dextrin to ethanol were isolated from samples collected from Brazilian factories in which cassava flour is produced. Considerable alcohol production was observed for all the strains selected. One strain (DI-10) fermented starch rapidly and secreted 5 times as much amylolytic enzyme than that observed for Schwanniomyces alluvius UCD 54-83. This strain and three other similar isolates were classified as Saccharomyces cerevisiae var. diastaticus by morphological and physiological characteristics and molecular taxonomy.

Laluce, C.; Bertolini, M.C.; Ernandes, J.R. (Universidade Estadual Paulista, Sao Paulo (Brazil)); Martini, A.V.; Martini, A. (Universita de Perugia (Italy))

1988-10-01

350

Physiological role of d -amino acid- N -acetyltransferase of Saccharomyces cerevisiae : detoxification of d -amino acids  

Microsoft Academic Search

Saccharomyces cerevisiae is sensitive to d-amino acids: those corresponding to almost all proteinous l-amino acids inhibit the growth of yeast even at low concentrations (e.g. 0.1 mM). We have determined that d-amino acid-N-acetyltransferase (DNT) of the yeast is involved in the detoxification of d-amino acids on the basis of the following findings. When the DNT gene was disrupted, the resulting mutant

Geok-Yong Yow; Takuma Uo; Tohru Yoshimura; Nobuyoshi Esaki

2006-01-01

351

Expression of an Aspergillus niger Phytase Gene (phyA )i n Saccharomyces cerevisiae  

Microsoft Academic Search

Phytase improves the bioavailability of phytate phosphorus in plant foods to humans and animals and reduces phosphorus pollution of animal waste. Our objectives were to express an Aspergillus niger phytase gene (phyA )i nSaccharomyces cerevisiae and to determine the effects of glycosylation on the phytase's activity and thermostability. A 1.4-kb DNA fragment containing the coding region of the phyA gene

YANMING HAN; DAVID B. WILSON; XIN GEN LEI

1999-01-01

352

A complete set of marked telomeres in Saccharomyces cerevisiae for physical mapping and cloning  

Microsoft Academic Search

Each telomere in a single strain (S288C) of Saccharomyces cerevisiae was marked with a URA3 containing integrating vector having telomeric TGâââ sequences. Efficiency of integrative transformation was enhanced by creating single random double-strand breaks in the integrating vector using DNAseI in the presence of Mn{sup 2+} ions. A total of 327 transformants were screened by CHEF gels of intact chromosomal

Edward J. Louis; Rhona H. Borts

1995-01-01

353

High activity of xylose reductase and xylitol dehydrogenase improves xylose fermentation by recombinant Saccharomyces cerevisiae  

Microsoft Academic Search

Xylose fermentation performance was studied of a previously developed Saccharomyces cerevisiae strain TMB 3057, carrying high xylose reductase (XR) and xylitol dehydrogenase (XDH) activity, overexpressed non-oxidative\\u000a pentose phosphate pathway (PPP) and deletion of the aldose reductase gene GRE3. The fermentation performance of TMB 3057 was significantly improved by increased ethanol production and reduced xylitol\\u000a formation compared with the reference strain

Kaisa Karhumaa; Romain Fromanger; Bärbel Hahn-Hägerdal; Marie-F. Gorwa-Grauslund

2007-01-01

354

Tolerance and stress response to ethanol in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

Eukaryotic cells have developed diverse strategies to combat the harmful effects of a variety of stress conditions. In the\\u000a model yeast Saccharomyces cerevisiae, the increased concentration of ethanol, as the primary fermentation product, will influence the membrane fluidity and be\\u000a toxic to membrane proteins, leading to cell growth inhibition and even death. Though little is known about the complex signal

Junmei Ding; Xiaowei Huang; Lemin Zhang; Na Zhao; Dongmei Yang; Keqin Zhang

2009-01-01

355

Analysis of factors responsible for the regeneration to intact cells from sphaeroplasts of Saccharomyces cerevisiae  

Microsoft Academic Search

The regeneration of Saccharomyces cerevisiae, NCIM 3288, cells from its sphaeroplasts were found to be influenced by a number of factors. The most suitable conditions of regeneration were also dependent on growth medium, that is, using malt-extractglucose-yeast extract-peptone (MGYP) medium: mannitol 0.7 M, pH 6.5, 30 °C and using yeast extract-peptone-glucose (YPG) medium: sucrose 0.7 M, pH 5.0 and 30

J. Anjani Kumari; T. Panda

1994-01-01

356

Transformation of intact cells of Saccharomyces cerevisiae by square wave pulses using castellated microelectrodes  

Microsoft Academic Search

vGenetic transformation of intact cells of Saccharomyces cerevisiae with an expression vector pYES 2, to efficiencies of 105 to 106 by high voltage electroporation is presented. Prototrophic transformants of yeast expressing resistance to ampicillin were obtained by subjecting the mixture of cells and DNA to a single square wave pulse at an amplitude of 2.5, 2.75 and 3.0 kV\\/cm in

G. L. Prasanna; T. Panda; P. Prabhakar Rao

1997-01-01

357

A Peroxisomal Glutathione Transferase of Saccharomyces cerevisiae Is Functionally Related to Sulfur Amino Acid Metabolism  

Microsoft Academic Search

Saccharomyces cerevisiae cells contain three omega-class glutathione transferases with glutaredoxin activity (Gto1, Gto2, and Gto3), in addition to two glutathione transferases (Gtt1 and Gtt2) not classifiable into standard classes. Gto1 is located at the peroxisomes, where it is targeted through a PTS1-type sequence, whereas Gto2 and Gto3 are in the cytosol. Among the GTO genes, GTO2 shows the strongest induction

Lina Barreto; Ana Garcera; Kristina Jansson; Per Sunnerhagen; Enrique Herrero

2006-01-01

358

Engineering of the metabolism of Saccharomyces cerevisiae for anaerobic production of mannitol  

Microsoft Academic Search

Under anaerobic conditions, Saccharomyces cerevisiae uses NADH-dependent glycerol-3-phosphate dehydrogenase (Gpd1p and Gpd2p) to re-oxidize excess NADH, yielding substantial amounts of glycerol. In a ?gpd1 ?gpd2 double-null mutant, the necessary NAD+ regeneration through glycerol production is no longer possible, and this mutant does not grow under anaerobic conditions. The excess NADH formed can potentially be used to drive other NADH-dependent reactions

Roeland Costenoble; Lennart Adler; Claes Niklasson; Gunnar Lidén

2003-01-01

359

Exchangeable zinc ions transiently accumulate in a vesicular compartment in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

The baker’s yeast Saccharomyces cerevisiae was used as a model to visualize intracellular labile zinc under conditions of nutritional zinc imbalance. Zinc-specific staining was performed in yeast cells using both Zinquin fluorescence and zinc–selenium autometallography. Both techniques resulted in specific labeling of an intracellular vesicular compartment that was present in wild type cells as well as in the vacuolar Zn

Chiara Devirgiliis; Chiara Murgia; Gorm Danscher; Giuditta Perozzi

2004-01-01

360

Interactions between mutations for sensitivity to psoralen photoaddition (PSO) and to radiation (rad) in Saccharomyces cerevisiae  

Microsoft Academic Search

The mode of interaction in haploid Saccharomyces cerevisiae of two PSO mutations with each other and with rad mutations affected in their excision resynthesis (rad3), error-prone (rad6), and deoxyribonucleic acid double-strand break (rad52) repair pathways was determined for various double mutant combinations. Survival data for 8-methoxypsoralen photoaddition, 254-nm ultraviolet light and gamma rays are presented. For 8-methoxypsoralen photoaddition, which induces

J. A. P. Henriques; E. Moustacchi

1981-01-01

361

The DNA repair gene PSO3 of Saccharomyces cerevisiae belongs to the RAD3 epistasis group  

Microsoft Academic Search

The mutant allele pso3-1 of Saccharomyces cerevisiae confers sensitivity to treatment with UV365nm (UVA) light-activated mono- and bi-functional psoralens. When pso3-1 is combined in double mutants with selected rad and pso mutant alleles and subjected to 8-MOP+UVA treatment, epistatic interaction with regard to survival is observed with pso1, pso2, and rad3. With the same treatment the combination of pso3-1 with

Mara S. Benfato; Martin Brendel; João A. P. Henriques

1992-01-01

362

Which yeast species shall I choose? Saccharomyces cerevisiae versus Pichia pastoris (review  

E-print Network

Having decided on yeast as a production host, the choice of species is often the first question any researcher new to the field will ask. With over 500 known species of yeast to date, this could pose a significant challenge. However, in reality, only very few species of yeast have been employed as host organisms for the production of recombinant proteins. The two most widely used, Saccharomyces cerevisiae and Pichia pastoris, are compared and contrasted here.

Richard Aj Darby; Stephanie P Cartwright; Marvin V. Dilworth; Roslyn M Bill

2012-01-01

363

Molecular characterization of CDC42, a Saccharomyces cerevisiae gene involved in the development of cell polarity  

Microsoft Academic Search

The Saccharomyces cerevisiae CDC42 gene product is involved in the morphogenetic events of the cell division cycle; temperature-sensitive cdc42 mu- tants are unable to form buds and display delocalized cell-surface deposition at the restrictive temperature (Adams, A. E. M., D. I. Johnson, R. M. Longnecker, B. E Sloat, and J. R. Pringle. 1990. J. Cell Biol. 111:131-142). To begin a

Douglas I. Johnson; John R. Pringle

1990-01-01

364

RAD9 gene controls the cell cycle response to DNA damage in Saccharomyces cerevisiae  

Microsoft Academic Search

Cell division is arrested in many organisms in response to DNA damage. Examinations of the genetic basis for this response in the yeast Saccharomyces cerevisiae indicate that the RAD9 gene product is essential for arrest of cell division induced by DNA damage. Wild-type haploid cells irradiated with x-rays either arrest or delay cell division in the G2 phase of the

T. A. Weinert; L. H. Hartwell

1988-01-01

365

Two Saccharomyces cerevisiae kinesin-related gene products required for mitotic spindle assembly  

Microsoft Academic Search

Two Saccharomyces cerevisiae genes, CIN8 and KIP1 (a.k.a. CIN9), were identified by their re- quirement for normal chromosome segregation. Both genes encode polypeptides related to the heavy chain of the microtubule-based force-generating enzyme kinesin. Cin8p was found to be required for pole separation during mitotic spindle assembly at 37~ although overproduced Kiplp could substitute. At lower temperatures, the activity of

M. Andrew Hoyt; Ling He; Kek Khee Loo; William S. Saunders

1992-01-01

366

Large-scale prediction of Saccharomyces cerevisiae gene function using overlapping transcriptional clusters  

Microsoft Academic Search

Genome sequencing has led to the discovery of tens of thousands of potential new genes. Six years after the sequencing of the well-studied yeast Saccharomyces cerevisiae and the discovery that its genome encodes ?6,000 predicted proteins, more than 2,000 have not yet been characterized experimentally, and determining their functions seems far from a trivial task. One crucial constraint is the

Lani F. Wu; Timothy R. Hughes; Armaity P. Davierwala; Mark D. Robinson; Roland Stoughton; Steven J. Altschuler

2002-01-01

367

High-level secretion of human ? 1-antitrypsin from Saccharomyces cerevisiae using inulinase signal sequence  

Microsoft Academic Search

The use of a proper signal sequence is one of the major determinants for the efficient secretion of heterologous proteins from yeast. The signal sequence derived from inulinase (INU1A) of Kluyveromyces marxianus was evaluated in directing the secretion of a human glycoprotein, ?1-antitrypsin (?1-AT), from Saccharomyces cerevisiae. A yeast expression vector for ?1-AT was constructed by placing the coding sequence

Hyun Ah Kang; Soo Wan Nam; Ki-sun Kwon; Bong Hyun Chung; Myeong-hee Yu

1996-01-01

368

Spermidine or Spermine is Essential for the Aerobic Growth of Saccharomyces cerevisiae  

Microsoft Academic Search

A null mutation in the SPE2 gene of Saccharomyces cerevisiae, encoding S-adenosylmethionine decarboxylase, results in cells with no detectable S-adenosylmethionine decarboxylase, spermidine, and spermine. This mutant has an absolute requirement for spermidine or spermine for growth; this requirement is not satisfied by putrescine. Polyamine-depleted cells show a number of microscopic abnormalities that are similar to those reported for several cell

David Balasundaram; Celia White Tabor; Herbert Tabor

1991-01-01

369

Localization and Cell Surface Anchoring of the Saccharomyces cerevisiae Flocculation Protein Flo1p  

Microsoft Academic Search

The Saccharomyces cerevisiae FLO1 gene encodes a large 1,536-amino-acid serine- and threonine-rich protein involved in flocculation. We have assessed the localization of Flo1p by immunoelectron microscopy, and in this study we show that this protein is located in the external mannoprotein layer of the cell wall, at the plasma membrane level and in the periplasm. The protein was also visualized

MURIEL BONY; DENISE THINES-SEMPOUX; PIERRE BARRE; BUNO BLONDIN

1997-01-01

370

Fractionation of Phenolic Compounds Extracted from Propolis and Their Activity in the Yeast Saccharomyces cerevisiae  

PubMed Central

We have here investigated the activities of Slovenian propolis extracts in the yeast Saccharomyces cerevisiae, and identified the phenolic compounds that appear to contribute to these activities. We correlated changes in intracellular oxidation and cellular metabolic energy in these yeasts with the individual fractions of the propolis extracts obtained following solid-phase extraction. The most effective fraction was further investigated according to its phenolic compounds. PMID:23409133

Petelinc, Tanja; Polak, Tomaz; Demsar, Lea; Jamnik, Polona

2013-01-01

371

Analysis of the Schwanniomyces occidentalis SWA2 gene promoter in Saccharomyces cerevisiae  

Microsoft Academic Search

The effect of different carbon sources on the expression in Saccharomyces cerevisiae of the SWA2 ?-amylase gene from Schwanniomyces occidentalis was studied from constructs containing its 5? region (?223 to +15), which were fused in-frame to the lacZ gene coding sequence. Maximal expression was achieved with the non-fermentable substrates ethanol and\\/or glycerol, whereas lower levels were found with maltose or

T. A Carmona; A Jiménez; M Fernández Lobato

2002-01-01

372

mRNAs Encoding Telomerase Components and Regulators Are Controlled by UPF Genes in Saccharomyces cerevisiae  

Microsoft Academic Search

Telomeres, the chromosome ends, are maintained by a balance of activities that erode and replace the terminal DNA sequences. Furthermore, telomere-proximal genes are often silenced in an epigenetic manner. In Saccharomyces cerevisiae, average telomere length and telomeric silencing are reduced by loss of function of UPF genes required in the nonsense-mediated mRNA decay (NMD) pathway. Because NMD controls the mRNA

Jeffrey N. Dahlseid; Jodi Lew-Smith; Michael J. Lelivelt; Shinichiro Enomoto; Amanda Ford; Michelle Desruisseaux; Mark McClellan; Neal Lue; Michael R. Culbertson; Judith Berman

2003-01-01

373

Inhibition of malolactic fermentation by a peptide produced by Saccharomyces cerevisiae during alcoholic fermentation  

Microsoft Academic Search

The ability of Saccharomyces to inhibit Oenococcus oeni during the alcoholic fermentation by mechanisms other than SO2 production was investigated. During fermentation in synthetic grape juice, S. cerevisiae strain RUBY.ferm inhibited the malolactic fermentation by O. oeni while strain EC1118 did not despite both strains producing similar amounts of SO2. The bacterial inhibition exerted by RUBY.ferm was diminished when the

James P. Osborne; Charles G. Edwards

2007-01-01

374

Quantitative transcription dynamic analysis reveals candidate genes and key regulators for ethanol tolerance in Saccharomyces cerevisiae  

Microsoft Academic Search

BACKGROUND: Derived from our lignocellulosic conversion inhibitor-tolerant yeast, we generated an ethanol-tolerant strain Saccharomyces cerevisiae NRRL Y-50316 by enforced evolutionary adaptation. Using a newly developed robust mRNA reference and a master equation unifying gene expression data analyses, we investigated comparative quantitative transcription dynamics of 175 genes selected from previous studies for an ethanol-tolerant yeast and its closely related parental strain.

Menggen Ma; Lewis Z Liu

2010-01-01

375

Vacuolar morphology of Saccharomyces cerevisiae during the process of wine making and Japanese sake brewing  

Microsoft Academic Search

Although ethanol and osmotic stress affect the vacuolar morphology of Saccharomyces cerevisiae, little information is available about changes in vacuolar morphology during the processes of wine making and Japanese sake (rice wine) brewing. Here, we elucidated changes in the morphology of yeast vacuoles using Zrc1p-GFP, a vacuolar membrane\\u000a protein, so as to better understand yeast physiology during the brewing process.

Shingo Izawa; Kayo Ikeda; Takeo Miki; Yoshinori Wakai; Yoshiharu Inoue

2010-01-01

376

Synergistic temperature and ethanol effect on Saccharomyces cerevisiae dynamic behaviour in ethanol bio-fuel production  

Microsoft Academic Search

The impact of ethanol and temperature on the dynamic behaviour of Saccharomyces cerevisiae in ethanol biofuel production was studied using an isothermal fed-batch process at five different temperatures. Fermentation parameters and kinetics were quantified. The best performances were found at 30 and 33°C around 120 g l -1 ethanol produced in 30 h with a slight benefit for growth at 30°C and for

A. S. Aldiguier; S. Alfenore; X. Cameleyre; G. Goma; J. L. Uribelarrea; S. E. Guillouet; C. Molina-Jouve

2004-01-01

377

Heterologous expression and secretion of sweet potato peroxidase isoenzyme A1 in recombinant Saccharomyces cerevisiae  

Microsoft Academic Search

A vector system has been developed to express isoenzyme A1 of sweet potato peroxidase (POD) and was introduced into Saccharomyces cerevisiae. The system contains the signal sequence of Aspergillus oryzae a-amylase to facilitate the extracellular secretion of peroxidase under the control of constitutive glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter. In a batch culture using YNBDCA medium (yeast nitrogen base without amino acids

Tae-Hyeo Kim; Joon-Ki Jung; Sang-Soo Kwak; Soo-Wan Nam; Moon-Jin Chun; Young-Hoon Park

2002-01-01

378

Decolourization of azo dye methyl red by Saccharomyces cerevisiae MTCC 463  

Microsoft Academic Search

Saccharomyces cerevisiae MTCC 463 decolourizes toxic azo dye, methyl red by degradation process. Methyl red (100mgl?1) is degraded completely within 16min in plain distilled water under static anoxic condition, at the room temperature. Effect of physicochemical parameters (pH of medium, composition of medium, concentration of cells, concentration of dye, temperature and agitation) on methyl red decolourization focused the optimal condition

J. P. Jadhav; G. K. Parshetti; S. D. Kalme; S. P. Govindwar

2007-01-01

379

Efficient expression and secretion of Aspergillus niger RH5344 polygalacturonase in Saccharomyces cerevisiae  

Microsoft Academic Search

An Aspergillus niger endopolygalacturonase (EC 3.2.1.15) cDNA was expressed in the yeast Saccharomyces cerevisiae. Secretion of the protein into the growth medium was efficiently directed by the fungal leader sequence, and processing occurred at the same site as in Aspergillus. The expression level was significantly enhanced by using a “short” version of the yeast ADHI promoter. An additional increase in

C. Lang; A. C. Looman

1995-01-01

380

Engineering of Saccharomyces cerevisiae for Efficient Anaerobic Alcoholic Fermentation of L-Arabinose  

Microsoft Academic Search

For cost-effective and efficient ethanol production from lignocellulosic fractions of plant biomass, the conversion of not only major constituents, such as glucose and xylose, but also less predominant sugars, such as L-arabinose, is required. Wild-type strains of Saccharomyces cerevisiae, the organism used in industrial ethanol production, cannot ferment xylose and arabinose. Although metabolic and evolutionary engineering has enabled the efficient

H. Wouter Wisselink; Maurice J. Toirkens; M. Del Rosario Franco Berriel; A. A. Winkler; J. P. Van Dijken; J. T. Pronk; A. J. A. Van Maris

2007-01-01

381

Use of Saccharomyces cerevisiae cells immobilized on orange peel as biocatalyst for alcoholic fermentation  

Microsoft Academic Search

A biocatalyst was prepared by immobilizing a commercial Saccharomyces cerevisiae strain (baker’s yeast) on orange peel pieces for use in alcoholic fermentation and for fermented food applications. Cell immobilization was shown by electron microscopy and by the efficiency of the immobilized biocatalyst for alcoholic fermentation of various carbohydrate substrates (glucose, molasses, raisin extracts) and at various temperatures (30–15°C). Fermentation times

S. Plessas; A. Bekatorou; A. A. Koutinas; M. Soupioni; I. M. Banat; R. Marchant

2007-01-01

382

Analysis of Plasmid Deletion Induced by Ionizing Radiation in Yeast Saccharomyces cerevisiae  

SciTech Connect

The article is dedicated to the research of plasmid system YCpL2 with help of quantitative analysis of deletion formation. The cells of yeast Saccharomyces cerevisiae were irradiated by {gamma}-ray with the flux of 0.7 Gy/min and energy of 1.3 MeV as well as heavy ion beam {sup 11}B with energy 32 MeV/n. The deletion of plasmid DNA has been analyzed by genetic and restriction analysis.

Yatsevich, E.; Stepanova, A.; Koltovaya, N. [Joint Institute for Nuclear Research, Dubna, Moscow Reg. (Russian Federation); Sprincova, A. [Joint Institute for Nuclear Research, Dubna, Moscow Reg. (Russian Federation); Institute of Experimental Physics Slovak Academy of Science, Kosice (Slovakia)

2007-11-26

383

The effect of millimeter waves at the yeast Saccharomyces cerevisiae during heliogeophysical disturbances  

NASA Astrophysics Data System (ADS)

The isolated and combined effect of heliogeophysical factors and low intensive electromagnetic radiation of millimeter diapason at the metachromasia reaction of the yeast Saccharomyces cerevisiae was studied. It was established that longterm influence of EMR 65 GHz induced changes in the response of cells towards heliogeomagnetic disturbance. On our opinion millimeter waves may reduce the effect of heliogeophysical factors on living organisms because of destabilization of the intracellular water structure.

Rogacheva, Svetlana M.; Babaeva, Milena I.

2013-02-01

384

Enantioselective reductions of ethyl 2-oxo-4-phenylbutyrate by Saccharomyces cerevisiae dehydrogenases  

Microsoft Academic Search

A set of fusion proteins consisting of glutathione S-transferase linked to the N-terminus of putative dehydrogenases produced by baker’s yeast (Saccharomyces cerevisiae) was screened for the reduction of ethyl 2-oxo-4-phenylbutyrate in the presence of NADH and NADPH. Two dehydrogenases—Ypr1p and Gre2p—rapidly reduced this ?-ketoester, providing the (R)- and (S)-alcohol, respectively, with high stereoselectivities. The same enzymes were over-expressed in their

Iwona Kaluzna; Amy A. Andrew; Mariana Bonilla; Mark R. Martzen; Jon D. Stewart

2002-01-01

385

RNA Polymerase II Elongation Factors of Saccharomyces cerevisiae: a Targeted Proteomics Approach  

Microsoft Academic Search

To physically characterize the web of interactions connecting the Saccharomyces cerevisiae proteins suspected to be RNA polymerase II (RNAPII) elongation factors, subunits of Spt4\\/Spt5 and Spt16\\/Pob3 (corresponding to human DSIF and FACT), Spt6, TFIIF (Tfg1, -2, and -3), TFIIS, Rtf1, and Elongator (Elp1, -2, -3, -4, -5, and -6) were affinity purified under conditions designed to minimize loss of associated

Nevan J. Krogan; Minkyu Kim; Seong Hoon Ahn; Guoqing Zhong; Michael S. Kobor; Gerard Cagney; Andrew Emili; Ali Shilatifard; Stephen Buratowski; Jack F. Greenblatt

2002-01-01

386

New Potential Cell Wall Glucanases of Saccharomyces cerevisiae and Their Involvement in Mating  

Microsoft Academic Search

Biotinylation of intact Saccharomyces cerevisiae cells with a nonpermeant reagent (Sulfo-NHS-LC-Biotin) al- lowed the identification of seven cell wall proteins that were released from intact cells by dithiothreitol (DTT). By N-terminal sequencing, three of these proteins were identified as the known proteins b-exoglucanase 1 (Exg1p), b-endoglucanase (Bgl2p), and chitinase (Cts1p). One protein was related to the PIR protein family, whereas

CORINNA CAPPELLARO; VLADIMIR MRSA; WIDMAR TANNER

1998-01-01

387

Helicase Hmi1 stimulates the synthesis of concatemeric mitochondrial DNA molecules in yeast Saccharomyces cerevisiae  

Microsoft Academic Search

Hmi1p is a helicase in the yeast Saccharomyces cerevisiae required for maintenance of the wild-type mitochondrial genome. Disruption of the HMI1 ORF generates ?- and ?0 cells. Here we demonstrate that, in ?- yeast strains, Hmi1p stimulates the synthesis of long concatemeric mitochondrial DNA molecules associated with a reduction in the number of nucleoids used for mitochondrial DNA packaging. Surprisingly,

Tiina Sedman; Priit Jõers; Silja Kuusk; Juhan Sedman

2005-01-01

388

Interactions between Kluyveromyces marxianus and Saccharomyces cerevisiae in tequila must type medium fermentation.  

PubMed

Traditional tequila fermentation is a complex microbial process performed by different indigenous yeast species. Usually, they are classified in two families: Saccharomyces and Non-Saccharomyces species. Using mixed starter cultures of several yeasts genera and species is nowadays considered to be beneficial to enhance the sensorial characteristics of the final products (taste, odor). However, microbial interactions occurring in such fermentations need to be better understood to improve the process. In this work, we focussed on a Saccharomyces cerevisiae/Kluyveromyces marxianus yeast couple. Indirect interactions due to excreted metabolites, thanks to the use of a specific membrane bioreactor, and direct interaction due to cell-to-cell contact have been explored. Comparison of pure and mixed cultures was done in each case. Mixed cultures in direct contact showed that both yeast were affected but Saccharomyces rapidly dominated the cultures whereas Kluyveromyces almost disappeared. In mixed cultures with indirect contact the growth of Kluyveromyces was decreased compared to its pure culture but its concentration could be maintained whereas the growth of Saccharomyces was enhanced. The loss of viability of Kluyveromyces could not be attributed only to ethanol. The sugar consumption and ethanol production in both cases were similar. Thus the interaction phenomena between the two yeasts are different in direct and indirect contact, Kluyveromyces being always much more affected than Saccharomyces. PMID:24677041

Lopez, Claudia Lorena Fernandez; Beaufort, Sandra; Brandam, Cédric; Taillandier, Patricia

2014-08-01

389

Candida zemplinina Can Reduce Acetic Acid Produced by Saccharomyces cerevisiae in Sweet Wine Fermentations  

PubMed Central

In this study we investigated the possibility of using Candida zemplinina, as a partner of Saccharomyces cerevisiae, in mixed fermentations of must with a high sugar content, in order to reduce its acetic acid production. Thirty-five C. zemplinina strains, which were isolated from different geographic regions, were molecularly characterized, and their fermentation performances were determined. Five genetically different strains were selected for mixed fermentations with S. cerevisiae. Two types of inoculation were carried out: coinoculation and sequential inoculation. A balance between the two species was generally observed for the first 6 days, after which the levels of C. zemplinina started to decrease. Relevant differences were observed concerning the consumption of sugars, the ethanol and glycerol content, and acetic acid production, depending on which strain was used and which type of inoculation was performed. Sequential inoculation led to the reduction of about half of the acetic acid content compared to the pure S. cerevisiae fermentation, but the ethanol and glycerol amounts were also low. A coinoculation with selected combinations of S. cerevisiae and C. zemplinina resulted in a decrease of ?0.3 g of acetic acid/liter, while maintaining high ethanol and glycerol levels. This study demonstrates that mixed S. cerevisiae and C. zemplinina fermentation could be applied in sweet wine fermentation to reduce the production of acetic acid, connected to the S. cerevisiae osmotic stress response. PMID:22247148

Rantsiou, Kalliopi; Dolci, Paola; Giacosa, Simone; Torchio, Fabrizio; Tofalo, Rosanna; Torriani, Sandra; Suzzi, Giovanna; Rolle, Luca

2012-01-01

390

The distribution of inverted repeat sequences in the Saccharomyces cerevisiae genome  

PubMed Central

Although a variety of possible functions have been proposed for inverted repeat sequences (IRs), it is not known which of them might occur in vivo. We investigate this question by assessing the distributions and properties of IRs in the Saccharomyces cerevisiae (SC) genome. Using the IRFinder algorithm we detect 100,514 IRs having copy length greater than 6 bp and spacer length less than 77 bp. To assess statistical significance we also determine the IR distributions in two types of randomization of the S. cerevisiae genome. We find that the S. cerevisiae genome is significantly enriched in IRs relative to random. The S. cerevisiae IRs are significantly longer and contain fewer imperfections than those from the randomized genomes, suggesting that processes to lengthen and/or correct errors in IRs may be operative in vivo. The S. cerevisiae IRs are highly clustered in intergenic regions, while their occurrence in coding sequences is consistent with random. Clustering is stronger in the 3? flanks of genes than in their 5? flanks. However, the S. cerevisiae genome is not enriched in those IRs that would extrude cruciforms, suggesting that this is not a common event. Various explanations for these results are considered. Electronic supplementary material The online version of this article (doi:10.1007/s00294-010-0302-6) contains supplementary material, which is available to authorized users. PMID:20446088

Benson, Gary; Gelfand, Yevgeniy; Benham, Craig J.

2010-01-01

391

Ethanol production by Saccharomyces cerevisiae using lignocellulosic hydrolysate from Chrysanthemum waste degradation.  

PubMed

Ethanol production derived from Saccharomyces cerevisiae fermentation of a hydrolysate from floriculture waste degradation was studied. The hydrolysate was produced from Chrysanthemum (Dendranthema grandiflora) waste degradation by Pleurotus ostreatus and characterized to determine the presence of compounds that may inhibit fermentation. The products of hydrolysis confirmed by HPLC were cellobiose, glucose, xylose and mannose. The hydrolysate was fermented by S. cerevisiae, and concentrations of biomass, ethanol, and glucose were determined as a function of time. Results were compared to YGC modified medium (yeast extract, glucose and chloramphenicol) fermentation. Ethanol yield was 0.45 g g(-1), 88 % of the maximal theoretical value. Crysanthemum waste hydrolysate was suitable for ethanol production, containing glucose and mannose with adequate nutrients for S. cerevisiae fermentation and low fermentation inhibitor levels. PMID:23117675

Quevedo-Hidalgo, Balkys; Monsalve-Marín, Felipe; Narváez-Rincón, Paulo César; Pedroza-Rodríguez, Aura Marina; Velásquez-Lozano, Mario Enrique

2013-03-01

392

A protocol for the subcellular fractionation of Saccharomyces cerevisiae using nitrogen cavitation and density gradient centrifugation.  

PubMed

Most protocols for yeast subcellular fractionation involve the use of mechanical shear forces to lyse the spheroplasts produced by the enzymatic digestion of the Saccharomyces cerevisiae cell wall. These mechanical homogenization procedures often involve the manual use of devices such as the Dounce homogenizer, and so are very operator-dependent and, in consequence, lack reproducibility. Here, we report a highly reproducible method of homogenizing yeast cells based on nitrogen cavitation. This has been optimized to allow efficient release of subcellular compartments that show a high degree of integrity. The protocol remains effective and reproducible across a range of sample volumes and buffer environments. The subsequent separation method, which employs both sucrose and iodixanol density gradients, has been developed to resolve the major membrane-bound compartments of S. cerevisiae. We present an integrated protocol that is fast, facile, robust and efficient and that will enable 'omics' studies of the subcellular compartments of S. cerevisiae and other yeasts. PMID:24510422

Wang, Yuchong; Lilley, Kathryn S; Oliver, Stephen G

2014-04-01

393

Parameter Optimization for Enhancement of Ethanol Yield by Atmospheric Pressure DBD-Treated Saccharomyces cerevisiae  

NASA Astrophysics Data System (ADS)

In this study, Saccharomyces cerevisiae (S. cerevisiae) was exposed to dielectric barrier discharge plasma (DBD) to improve its ethanol production capacity during fermentation. Response surface methodology (RSM) was used to optimize the discharge-associated parameters of DBD for the purpose of maximizing the ethanol yield achieved by DBD-treated S. cerevisiae. According to single factor experiments, a mathematical model was established using Box-Behnken central composite experiment design, with plasma exposure time, power supply voltage, and exposed-sample volume as impact factors and ethanol yield as the response. This was followed by response surface analysis. Optimal experimental parameters for plasma discharge-induced enhancement in ethanol yield were plasma exposure time of 1 min, power voltage of 26 V, and an exposed sample volume of 9 mL. Under these conditions, the resulting yield of ethanol was 0.48 g/g, representing an increase of 33% over control.

Dong, Xiaoyu; Yuan, Yulian; Tang, Qian; Dou, Shaohua; Di, Lanbo; Zhang, Xiuling

2014-01-01

394

amdSYM, a new dominant recyclable marker cassette for Saccharomyces cerevisiae  

PubMed Central

Despite the large collection of selectable marker genes available for Saccharomyces cerevisiae, marker availability can still present a hurdle when dozens of genetic manipulations are required. Recyclable markers, counterselectable cassettes that can be removed from the targeted genome after use, are therefore valuable assets in ambitious metabolic engineering programs. In the present work, the new recyclable dominant marker cassette amdSYM, formed by the Ashbya gossypii TEF2 promoter and terminator and a codon-optimized acetamidase gene (Aspergillus nidulans amdS), is presented. The amdSYM cassette confers S. cerevisiae the ability to use acetamide as sole nitrogen source. Direct repeats flanking the amdS gene allow for its efficient recombinative excision. As previously demonstrated in filamentous fungi, loss of the amdS marker cassette from S. cerevisiae can be rapidly selected for by growth in the presence of fluoroacetamide. The amdSYM cassette can be used in different genetic backgrounds and represents the first counterselectable dominant marker gene cassette for use in S. cerevisiae. Furthermore, using astute cassette design, amdSYM excision can be performed without leaving a scar or heterologous sequences in the targeted genome. The present work therefore demonstrates that amdSYM is a useful addition to the genetic engineering toolbox for Saccharomyces laboratory, wild, and industrial strains. PMID:23253382

Solis-Escalante, Daniel; Kuijpers, Niels GA; Bongaerts, Nadine; Bolat, Irina; Bosman, Lizanne; Pronk, Jack T; Daran, Jean-Marc; Daran-Lapujade, Pascale

2013-01-01

395

In vitro phosphorylation by cAMP-dependent protein kinase up-regulates recombinant Saccharomyces cerevisiae mannosylphosphodolichol synthase.  

PubMed

DPM1 is the structural gene for mannosylphosphodolichol synthase (i.e. Dol-P-Man synthase, DPMS) in Saccharomyces cerevisiae. Earlier studies with cDNA cloning and sequence analysis have established that 31-kDa DPMS of S. cerevisiae contains a consensus sequence (YRRVIS141) that can be phosphorylated by cAMP-dependent protein kinase (PKA). We have been studying the up-regulation of DPMS activity by protein kinase A-mediated phosphorylation in higher eukaryotes, and used the recombinant DPMS from S. cerevisiae in this study to advance our knowledge further. DPMS catalytic activity was indeed enhanced severalfold when the recombinant protein was phosphorylated in vitro. The rate as well as the magnitude of catalysis was higher with the phosphorylated enzyme. A similar increase in the catalytic activity was also observed when the in vitro phosphorylated recombinant DPMS was assayed as a function of increasing concentrations of exogenous dolichylmonophosphate (Dol-P). Kinetic studies indicated that there was no change in the Km for GDP-mannose between the in vitro phosphorylated and control recombinant DPMS, but the Vmax was increased by 6-fold with the phosphorylated enzyme. In vitro phosphorylated recombinant DPMS also exhibited higher enzyme turnover (kcat) and enzyme efficiency (kcat/Km). SDS-PAGE followed by autoradiography of the 32P-labeled DPMS detected a 31-kDa phosphoprotein, and immunoblotting with anti-phosphoserine antibody established the presence of a phosphoserine residue in in vitro phosphorylated recombinant DPMS. To confirm the phosphorylation activation of recombinant DPMS, serine 141 in the consensus sequence was replaced with alanine by PCR site-directed mutagenesis. The S141A DPMS mutant exhibited more than half-a-fold reduction in catalytic activity compared with the wild type when both were analyzed after in vitro phosphorylation. Thus, confirming that S. cerevisiae DPMS activity is indeed regulated by the cAMP-dependent protein phosphorylation signal, and the phosphorylation target is serine 141. PMID:15548536

Banerjee, Dipak K; Carrasquillo, Elena A; Hughey, Patsy; Schutzbach, John S; Martínez, Juan A; Baksi, Krishna

2005-02-11

396

Novel Q-intermediates in coq null yeast over-expressing Coq8 Over-expression of the Coq8 kinase in Saccharomyces cerevisiae coq null mutants allows for  

E-print Network

in Saccharomyces cerevisiae coq null mutants allows for accumulation of diagnostic intermediates of the Coenzyme Q6) biosynthesis are interdependent within a multi-protein complex in the yeast Saccharomyces cerevisiae. Lack

Paris-Sud XI, Université de

397

Abundant Gene-by-Environment Interactions in Gene Expression Reaction Norms to Copper within Saccharomyces cerevisiae  

PubMed Central

Genetic variation for plastic phenotypes potentially contributes phenotypic variation to populations that can be selected during adaptation to novel ecological contexts. However, the basis and extent of plastic variation that manifests in diverse environments remains elusive. Here, we characterize copper reaction norms for mRNA abundance among five Saccharomyces cerevisiae strains to 1) describe population variation across the full range of ecologically relevant copper concentrations, from starvation to toxicity, and 2) to test the hypothesis that plastic networks exhibit increased population variation for gene expression. We find that although the vast majority of the variation is small in magnitude (considerably <2-fold), not just some, but most genes demonstrate variable expression across environments, across genetic backgrounds, or both. Plastically expressed genes included both genes regulated directly by copper-binding transcription factors Mac1 and Ace1 and genes indirectly responding to the downstream metabolic consequences of the copper gradient, particularly genes involved in copper, iron, and sulfur homeostasis. Copper-regulated gene networks exhibited more similar behavior within the population in environments where those networks have a large impact on fitness. Nevertheless, expression variation in genes like Cup1, important to surviving copper stress, was linked with variation in mitotic fitness and in the breadth of differential expression across the genome. By revealing a broader and deeper range of population variation, our results provide further evidence for the interconnectedness of genome-wide mRNA levels, their dependence on environmental context and genetic background, and the abundance of variation in gene expression that can contribute to future evolution. PMID:23019066

Hodgins-Davis, Andrea; Adomas, Aleksandra B.; Warringer, Jonas; Townsend, Jeffrey P.

2012-01-01

398

Glycolysis in Saccharomyces cerevisiae: algorithmic exploration of robustness and origin of oscillations.  

PubMed

The glycolysis pathway in saccharomyces cerevisiae is considered, modeled by a dynamical system possessing a normally hyperbolic, exponentially attractive invariant manifold, where it exhibits limit cycle behavior. The fast dissipative action simplifies considerably the exploration of the system's robustness, since its dynamical properties are mainly determined by the slow dynamics characterizing the motion along the limit cycle on the slow manifold. This manifold expresses a number of equilibrations among components of the cellular mechanism that have a non-negligible projection in the fast subspace, while the motion along the slow manifold is due to components that have a non-negligible projection in the slow subspace. The characteristic time scale of the limit cycle can be directly altered by perturbing components whose projection in the slow subspace contributes to its generation. The same effect can be obtained indirectly by perturbing components whose projection in the fast subspace participates in the generated equilibrations, since the slow manifold will thus be displaced and the slow dynamics must adjust. Along the limit cycle, the characteristic time scale exhibits successively a dissipative and an explosive nature (leading towards or away from a fixed point, respectively). Depending on their individual contribution to the dissipative or explosive nature of the characteristic time scale, the components of the cellular mechanism can be classified as either dissipative or explosive ones. Since dissipative/explosive components tend to diminish/intensify the oscillatory behavior, one would expect that strengthening a dissipative/explosive component will diminish/intensify the oscillations. However, it is shown that strengthening dissipative (explosive) components might lead the system to amplified oscillations (fixed point). By employing the Computational Singular Perturbation method, it is demonstrated that such a behavior is due to the constraints imposed by the slow manifold. PMID:23517854

Kourdis, Panayotis D; Goussis, Dimitris A

2013-06-01

399

Screening for hydrolytic enzymes reveals Ayr1p as a novel triacylglycerol lipase in Saccharomyces cerevisiae.  

PubMed

Saccharomyces cerevisiae, as well as other eukaryotes, preserves fatty acids and sterols in a biologically inert form, as triacylglycerols and steryl esters. The major triacylglycerol lipases of the yeast S. cerevisiae identified so far are Tgl3p, Tgl4p, and Tgl5p (Athenstaedt, K., and Daum, G. (2003) YMR313c/TGL3 encodes a novel triacylglycerol lipase located in lipid particles of Saccharomyces cerevisiae. J. Biol. Chem. 278, 23317-23323; Athenstaedt, K., and Daum, G. (2005) Tgl4p and Tgl5p, two triacylglycerol lipases of the yeast Saccharomyces cerevisiae, are localized to lipid particles. J. Biol. Chem. 280, 37301-37309). We observed that upon cultivation on oleic acid, triacylglycerol mobilization did not come to a halt in a yeast strain deficient in all currently known triacylglycerol lipases, indicating the presence of additional not yet characterized lipases/esterases. Functional proteome analysis using lipase and esterase inhibitors revealed a subset of candidate genes for yet unknown hydrolytic enzymes on peroxisomes and lipid droplets. Based on the conserved GXSXG lipase motif, putative functions, and subcellular localizations, a selected number of candidates were characterized by enzyme assays in vitro, gene expression analysis, non-polar lipid analysis, and in vivo triacylglycerol mobilization assays. These investigations led to the identification of Ayr1p as a novel triacylglycerol lipase of yeast lipid droplets and confirmed the hydrolytic potential of the peroxisomal Lpx1p in vivo. Based on these results, we discuss a possible link between lipid storage, lipid mobilization, and peroxisomal utilization of fatty acids as a carbon source. PMID:24187129

Ploier, Birgit; Scharwey, Melanie; Koch, Barbara; Schmidt, Claudia; Schatte, Jessica; Rechberger, Gerald; Kollroser, Manfred; Hermetter, Albin; Daum, Günther

2013-12-13

400

Continuous co-fermentation of cellobiose and xylose by engineered Saccharomyces cerevisiae.  

PubMed

Simultaneous fermentation of cellobiose and xylose by an engineered Saccharomyces cerevisiae has been demonstrated in batch fermentation, suggesting the feasibility of continuous co-fermentation of cellulosic sugars. As industrial S. cerevisiae strains have known to possess higher ethanol productivity and robustness compared to laboratory S. cerevisiae strains, xylose and cellobiose metabolic pathways were introduced into a haploid strain derived from an industrial S. cerevisiae. The resulting strain (JX123-BTT) was able to ferment a mixture of cellobiose and xylose simultaneously in batch fermentation with a high ethanol yield (0.38 g/g) and productivity (2.00 g/L · h). Additionally, the JX123-BTT strain co-consumed glucose, cellobiose, and xylose under continuous culture conditions at a dilution rate of 0.05 h(-1) and produced ethanol resulting in 0.38 g/g of ethanol yield and 0.96 g/L · h of productivity. This is the first demonstration of co-fermentation of cellobiose and xylose by an engineered S. cerevisiae under continuous culture conditions. PMID:24140899

Ha, Suk-Jin; Kim, Soo Rin; Kim, Heejin; Du, Jing; Cate, Jamie H D; Jin, Yong-Su

2013-12-01

401

Efficient direct ethanol production from cellulose by cellulase- and cellodextrin transporter-co-expressing Saccharomyces cerevisiae  

PubMed Central

Efficient degradation of cellulosic biomass requires the synergistic action of the cellulolytic enzymes endoglucanase, cellobiohydrolase, and ?-glucosidase. Although there are many reports describing consolidation of hydrolysis and fermentation steps using recombinant Saccharomyces cerevisiae that express cellulolytic enzymes, the efficiency of cellulose degradation has not been sufficiently improved. Although the yeast S. cerevisiae cannot take up cellooligosaccharide, some fungi can take up and assimilate cellooligosaccharide through a cellodextrin transporter. In this study, a S. cerevisiae strain co-expressing genes for several cell surface display cellulases and the cellodextrin transporter was constructed for the purpose of improving the efficiency of direct ethanol fermentation from phosphoric acid swollen cellulose (PASC). The cellulase/cellodextrin transporter-coexpressing strain produced 1.7-fold more ethanol (4.3 g/L) from PASC during a 72-h fermentation than did a strain expressing cellulase only (2.5 g/L). Direct ethanol production from PASC by the recombinant S. cerevisiae strain was improved by co-expression of cellulase display and cellodextrin transporter genes. These results suggest that cellulase- and cellodextrin transporter-co-expressing S. cerevisiae could be a promising technology for efficient direct ethanol production from cellulose. PMID:23800294

2013-01-01

402

Molecular genetic study of introgression between Saccharomyces bayanus and S. cerevisiae.  

PubMed

The genomic constitution of different S. bayanus strains and natural interspecific Saccharomyces hybrids has been studied by genetic and molecular methods. Unlike S. bayanus var. uvarum, some S. bayanus var. bayanus strains (the type culture CBS 380, CBS 378, CBS 425, CBS 1548) harbour a number of S. cerevisiae subtelomeric sequences: Y', pEL50, SUC, RTM and MAL. The two varieties, having 86-100% nDNA-nDNA reassociation, are partly genetically isolated from one another but completely isolated from S. cerevisiae. Genetic and molecular data support the maintaining of var. bayanus and var. uvarum strains in the species S. bayanus. Using Southern hybridization with species-specific molecular markers, RFLP of the MET2 gene and flow cytometry analysis, we showed that the non-S. cerevisiae parents are different in lager brewing yeasts and in wine hybrid strains. Our results suggest that S. pastorianus is a hybrid between S. cerevisiae and S. bayanus var. bayanus, while S. bayanus var. uvarum contributed to the formation of the wine hybrids S6U and CID1. According to the partial sequence of ACT1 gene and flow cytometry analysis, strain CID1 is a triple hybrid between S. cerevisiae, S. kudriavzevii and S. bayanus var. uvarum. PMID:16240458

Naumova, Elena S; Naumov, Gennadi I; Masneuf-Pomarède, Isabelle; Aigle, Michel; Dubourdieu, Denis

2005-10-30

403

The genome sequence of the wine yeast VIN7 reveals an allotriploid hybrid genome with Saccharomyces cerevisiae and Saccharomyces kudriavzevii origins.  

PubMed

The vast majority of wine fermentations are performed principally by Saccharomyces cerevisiae. However, there are a growing number of instances in which other species of Saccharomyces play a predominant role. Interestingly, the presence of these other yeast species generally occurs via the formation of interspecific hybrids that contain genomic contributions from both S. cerevisiae and non-S. cerevisiae species. However, despite the large number of wine strains that are characterized at the genomic level, there remains limited information regarding the detailed genomic structure of hybrids used in winemaking. To address this, we describe the genome sequence of the thiol-releasing commercial wine yeast hybrid VIN7. VIN7 is shown to be an almost complete allotriploid interspecific hybrid that is comprised of a heterozygous diploid complement of S. cerevisiae chromosomes and a haploid Saccharomyces kudriavzevii genomic contribution. Both parental strains appear to be of European origin, with the S. cerevisiae parent being closely related to, but distinct from, the commercial wine yeasts QA23 and EC1118. In addition, several instances of chromosomal rearrangement between S. cerevisiae and S. kudriavzevii sequences were observed that may mark the early stages of hybrid genome consolidation. PMID:22136070

Borneman, Anthony R; Desany, Brian A; Riches, David; Affourtit, Jason P; Forgan, Angus H; Pretorius, Isak S; Egholm, Michael; Chambers, Paul J

2012-02-01

404

Copper Import into the Mitochondrial Matrix in Saccharomyces cerevisiae Is Mediated by Pic2, a Mitochondrial Carrier Family Protein*  

PubMed Central

Saccharomyces cerevisiae must import copper into the mitochondrial matrix for eventual assembly of cytochrome c oxidase. This copper is bound to an anionic fluorescent molecule known as the copper ligand (CuL). Here, we identify for the first time a mitochondrial carrier family protein capable of importing copper into the matrix. In vitro transport of the CuL into the mitochondrial matrix was saturable and temperature-dependent. Strains with a deletion of PIC2 grew poorly on copper-deficient non-fermentable medium supplemented with silver and under respiratory conditions when challenged with a matrix-targeted copper competitor. Mitochondria from pic2? cells had lower total mitochondrial copper and exhibited a decreased capacity for copper uptake. Heterologous expression of Pic2 in Lactococcus lactis significantly enhanced CuL transport into these cells. Therefore, we propose a novel role for Pic2 in copper import into mitochondria. PMID:23846699

Vest, Katherine E.; Leary, Scot C.; Winge, Dennis R.; Cobine, Paul A.

2013-01-01

405

Quantitative phosphoproteomics in fatty acid stimulated Saccharomyces cerevisiae.  

PubMed

This protocol describes the growth and stimulation, with the fatty acid oleate, of isotopically heavy and light S. cerevisiae cells. Cells are ground using a cryolysis procedure in a ball mill grinder and the resulting grindate brought into solution by urea solubilization. This procedure allows for the lysis of the cells in a metabolically inactive state, preserving phosphorylation and preventing reorientation of the phosphoproteome during cell lysis. Following reduction, alkylation, trypsin digestion of the proteins, the samples are desalted on C18 columns and the sample complexity reduced by fractionation using hydrophilic interaction chromatography (HILIC). HILIC columns preferentially retain hydrophilic molecules which is well suited for phosphoproteomics. Phosphorylated peptides tend to elute later in the chromatographic profile than the non phosphorylated counterparts. After fractionation, phosphopeptides are enriched using immobilized metal chromatography, which relies on charge-based affinities for phosphopeptide enrichment. At the end of this procedure the samples are ready to be quantitatively analyzed by mass spectrometry. PMID:19823167

Saleem, Ramsey A; Aitchison, John D

2009-01-01

406

Saccharomyces cerevisiae-based system for studying clustered DNA damages  

SciTech Connect

DNA-damaging agents can induce clustered lesions or multiply damaged sites (MDSs) on the same or opposing DNA strands. In the latter, attempts to repair MDS can generate closely opposed single-strand break intermediates that may convert non-lethal or mutagenic base damage into double-strand breaks (DSBs). We constructed a diploid S. cerevisiae yeast strain with a chromosomal context targeted by integrative DNA fragments carrying different damages to determine whether closely opposed base damages are converted to DSBs following the outcomes of the homologous recombination repair pathway. As a model of MDS, we studied clustered uracil DNA damages with a known location and a defined distance separating the lesions. The system we describe might well be extended to assessing the repair of MDSs with different compositions, and to most of the complex DNA lesions induced by physical and chemical agents.

Moscariello, M.M.; Sutherland, B.

2010-08-01

407

An improved map of conserved regulatory sites for Saccharomyces cerevisiae  

PubMed Central

Background The regulatory map of a genome consists of the binding sites for proteins that determine the transcription of nearby genes. An initial regulatory map for S. cerevisiae was recently published using six motif discovery programs to analyze genome-wide chromatin immunoprecipitation data for 203 transcription factors. The programs were used to identify sequence motifs that were likely to correspond to the DNA-binding specificity of the immunoprecipitated proteins. We report improved versions of two conservation-based motif discovery algorithms, PhyloCon and Converge. Using these programs, we create a refined regulatory map for S. cerevisiae by reanalyzing the same chromatin immunoprecipitation data. Results Applying the same conservative criteria that were applied in the original study, we find that PhyloCon and Converge each separately discover more known specificities than the combination of all six programs in the previous study. Combining the results of PhyloCon and Converge, we discover significant sequence motifs for 36 transcription factors that were previously missed. The new set of motifs identifies 636 more regulatory interactions than the previous one. The new network contains 28% more regulatory interactions among transcription factors, evidence of greater cross-talk between regulators. Conclusion Combining two complementary computational strategies for conservation-based motif discovery improves the ability to identify the specificity of transcriptional regulators from genome-wide chromatin immunoprecipitation data. The increased sensitivity of these methods significantly expands the map of yeast regulatory sites without the need to alter any of the thresholds for statistical significance. The new map of regulatory sites reveals a more elaborate and complex view of the yeast genetic regulatory network than was observed previously. PMID:16522208

MacIsaac, Kenzie D; Wang, Ting; Gordon, D Benjamin; Gifford, David K; Stormo, Gary D; Fraenkel, Ernest

2006-01-01

408

Characterization of Saccharomyces cerevisiae promoters for heterologous gene expression in Kluyveromyces marxianus.  

PubMed

Kluyveromyces marxianus is now considered one of the best choices of option for industrial applications of yeast because the strain is able to grow at high temperature, utilizes various carbon sources, and grows fast. However, the use of K. marxianus as a host for industrial applications is still limited. This limitation is largely due to a lack of knowledge on the characteristics of the promoters since the time and amount of protein expression is strongly dependent on the promoter employed. In this study, four well-known constitutive promoters (P(CYC), P(TEF), P(GPD), and P(ADH)) of Saccharomyces cerevisiae were characterized in K. marxianus in terms of protein expression level and their stochastic behavior. After constructing five URA3-auxotrophic K. marxianus strains and a plasmid vector, four cassettes each comprising one of the promoters--the gene for the green fluorescence protein (GFP)--CYC1 terminator (T(CYC)) were inserted into the vector. GFP expression under the control of each one of the promoters was analyzed by reverse transcription PCR, fluorescence microscopy, and flow cytometer. Using these combined methods, the promoter strength was determined to be in the order of P(GPD) > P(ADH) ? P(TEF) > P(CYC). All promoters except for the P(CYC) exhibited three distinctive populations, including non-expressing cells, weakly expressing cells, and strongly expressing cells. The relative ratios between populations were strongly dependent on the promoter and culture time. Forward scattering was independent of GFP fluorescence intensity, indicating that the different fluorescence intensities were not just due to different cell sizes derived from budding. It also excluded the possibility that the non-expressing cells resulted from plasmid loss because plasmid stability was maintained at almost 100 % over the culture time. The same cassettes, cloned into a single copy plasmid pRS416 and transformed into S. cerevisiae, showed only one population. When the cassettes were integrated into the chromosome, the stochastic behavior was markedly reduced. These combined results imply that the gene expression stochasticity should be overcome in order to use this strain for delicate metabolic engineering, which would require the co-expression of several genes. PMID:22911091

Lee, Ki-Sung; Kim, Jun-Seob; Heo, Paul; Yang, Tae-Jun; Sung, Young-Je; Cheon, Yuna; Koo, Hyun Min; Yu, Byung Jo; Seo, Jin-Ho; Jin, Yong-Su; Park, Jae Chan; Kweon, Dae-Hyuk

2013-03-01

409

Selected non-Saccharomyces wine yeasts in controlled multistarter fermentations with Saccharomyces cerevisiae on alcoholic fermentation behaviour and wine aroma of cherry wines.  

PubMed

This study examined the effect of mixed fermentation of non-Saccharomyces (Torulaspora delbrueckii ZYMAFLORE Alpha(TD n. Sacch) and Metschnikowia pulcherrima JS22) and Saccharomyces cerevisiae yeasts (D254 and EC1118) on the production of cherry wines, in comparison with commonly used mono-culture. Results obtained during AF demonstrated that negligible inhibitory effect was observed in S. cerevisiae/Alpha pair, whereas a strong antagonistic effect was detected between MJS22 and S. cerevisiae strain, resulting in an early death of MJS22. For volatile components determined, S. cerevisiae/MJS22 couple was found to significantly boost the production of most detected compounds, more particularly in higher alcohols, esters, acids and terpenes; while the characteristic of S. cerevisiae/Alpha pair is an increase in fruity esters, higher alcohols and decrease in acid production. Sensory evaluation revealed that S. cerevisiae/MJS22 pair reinforced sweet, green and fatty notes to the cherry wines, and S. cerevisiae/Alpha trial enhanced the fruity odour and reduced green note. PMID:25084640

Sun, Shu Yang; Gong, Han Sheng; Jiang, Xiao Man; Zhao, Yu Ping

2014-12-01

410

Similarities and differences in the biochemical and enzymological properties of the four isomaltases from Saccharomyces cerevisiae.  

PubMed

The yeast Saccharomyces cerevisiae IMA multigene family encodes four isomaltases sharing high sequence identity from 65% to 99%. Here, we explore their functional diversity, with exhaustive in-vitro characterization of their enzymological and biochemical properties. The four isoenzymes exhibited a preference for the ?-(1,6) disaccharides isomaltose and palatinose, with Michaëlis-Menten kinetics and inhibition at high substrates concentration. They were also able to hydrolyze trisaccharides bearing an ?-(1,6) linkage, but also ?-(1,2), ?-(1,3) and ?-(1,5) disaccharides including sucrose, highlighting their substrate ambiguity. While Ima1p and Ima2p presented almost identical characteristics, our results nevertheless showed many singularities within this protein family. In particular, Ima3p presented lower activities and thermostability than Ima2p despite only three different amino acids between the sequences of these two isoforms. The Ima3p_R279Q variant recovered activity levels of Ima2p, while the Leu-to-Pro substitution at position 240 significantly increased the stability of Ima3p and supported the role of prolines in thermostability. The most distant protein, Ima5p, presented the lowest optimal temperature and was also extremely sensitive to temperature. Isomaltose hydrolysis by Ima5p challenged previous conclusions about the requirement of specific amino acids for determining the specificity for ?-(1,6) substrates. We finally found a mixed inhibition by maltose for Ima5p while, contrary to a previous work, Ima1p inhibition by maltose was competitive at very low isomaltose concentrations and uncompetitive as the substrate concentration increased. Altogether, this work illustrates that a gene family encoding proteins with strong sequence similarities can lead to enzyme with notable differences in biochemical and enzymological properties. PMID:24649402

Deng, Xu; Petitjean, Marjorie; Teste, Marie-Ange; Kooli, Wafa; Tranier, Samuel; François, Jean Marie; Parrou, Jean-Luc

2014-01-01

411

Similarities and differences in the biochemical and enzymological properties of the four isomaltases from Saccharomyces cerevisiae  

PubMed Central

The yeast Saccharomyces cerevisiae IMA multigene family encodes four isomaltases sharing high sequence identity from 65% to 99%. Here, we explore their functional diversity, with exhaustive in-vitro characterization of their enzymological and biochemical properties. The four isoenzymes exhibited a preference for the ?-(1,6) disaccharides isomaltose and palatinose, with Michaëlis–Menten kinetics and inhibition at high substrates concentration. They were also able to hydrolyze trisaccharides bearing an ?-(1,6) linkage, but also ?-(1,2), ?-(1,3) and ?-(1,5) disaccharides including sucrose, highlighting their substrate ambiguity. While Ima1p and Ima2p presented almost identical characteristics, our results nevertheless showed many singularities within this protein family. In particular, Ima3p presented lower activities and thermostability than Ima2p despite only three different amino acids between the sequences of these two isoforms. The Ima3p_R279Q variant recovered activity levels of Ima2p, while the Leu-to-Pro substitution at position 240 significantly increased the stability of Ima3p and supported the role of prolines in thermostability. The most distant protein, Ima5p, presented the lowest optimal temperature and was also extremely sensitive to temperature. Isomaltose hydrolysis by Ima5p challenged previous conclusions about the requirement of specific amino acids for determining the specificity for ?-(1,6) substrates. We finally found a mixed inhibition by maltose for Ima5p while, contrary to a previous work, Ima1p inhibition by maltose was competitive at very low isomaltose concentrations and uncompetitive as the substrate concentration increased. Altogether, this work illustrates that a gene family encoding proteins with strong sequence similarities can lead to enzyme with notable differences in biochemical and enzymological properties. PMID:24649402

Deng, Xu; Petitjean, Marjorie; Teste, Marie-Ange; Kooli, Wafa; Tranier, Samuel; François, Jean Marie; Parrou, Jean-Luc

2014-01-01

412

The Saccharomyces cerevisiae spindle pole body duplication gene MPS1 is part of a mitotic checkpoint  

PubMed Central

M-phase checkpoints inhibit cell division when mitotic spindle function is perturbed. Here we show that the Saccharomyces cerevisiae MPS1 gene product, an essential protein kinase required for spindle pole body (SPB) duplication (Winey et al., 1991; Lauze et al., 1995), is also required for M-phase check-point function. In cdc31-2 and mps2-1 mutants, conditional failure of SPB duplication results in cell cycle arrest with high p34CDC28 kinase activity that depends on the presence of the wild-type MAD1 checkpoint gene, consistent with checkpoint arrest of mitosis. In contrast, mps1 mutant cells fail to duplicate their SPBs and do not arrest division at 37 degrees C, exhibiting a normal cycle of p34CDC28 kinase activity despite the presence of a monopolar spindle. Double mutant cdc31-2, mps1-1 cells also fail to arrest mitosis at 37 degrees C, despite having SPB structures similar to cdc31-2 single mutants as determined by EM analysis. Arrest of mitosis upon microtubule depolymerization by nocodazole is also conditionally absent in mps1 strains. This is observed in mps1 cells synchronized in S phase with hydroxyurea before exposure to nocodazole, indicating that failure of checkpoint function in mps1 cells is independent of SPB duplication failure. In contrast, hydroxyurea arrest and a number of other cdc mutant arrest phenotypes are unaffected by mps1 alleles. We propose that the essential MPS1 protein kinase functions both in SPB duplication and in a mitotic checkpoint monitoring spindle integrity. PMID:8567717

1996-01-01

413

Adjustment of Trehalose Metabolism in Wine Saccharomyces cerevisiae Strains To Modify Ethanol Yields  

PubMed Central

The ability of Saccharomyces cerevisiae to efficiently produce high levels of ethanol through glycolysis has been the focus of much scientific and industrial activity. Despite the accumulated knowledge regarding glycolysis, the modification of flux through this pathway to modify ethanol yields has proved difficult. Here, we report on the systematic screening of 66 strains with deletion mutations of genes encoding enzymes involved in central carbohydrate metabolism for altered ethanol yields. Five of these strains showing the most prominent changes in carbon flux were selected for further investigation. The genes were representative of trehalose biosynthesis (TPS1, encoding trehalose-6-phosphate synthase), central glycolysis (TDH3, encoding glyceraldehyde-3-phosphate dehydrogenase), the oxidative pentose phosphate pathway (ZWF1, encoding glucose-6-phosphate dehydrogenase), and the tricarboxylic acid (TCA) cycle (ACO1 and ACO2, encoding aconitase isoforms 1 and 2). Two strains exhibited lower ethanol yields than the wild type (tps1? and tdh3?), while the remaining three showed higher ethanol yields. To validate these findings in an industrial yeast strain, the TPS1 gene was selected as a good candidate for genetic modification to alter flux to ethanol during alcoholic fermentation in wine. Using low-strength promoters active at different stages of fermentation, the expression of the TPS1 gene was slightly upregulated, resulting in a decrease in ethanol production and an increase in trehalose biosynthesis during fermentation. Thus, the mutant screening approach was successful in terms of identifying target genes for genetic modification in commercial yeast strains with the aim of producing lower-ethanol wines. PMID:23793638

Rossouw, D.; Heyns, E. H.; Setati, M. E.; Bosch, S.

2013-01-01

414

Adjustment of trehalose metabolism in wine Saccharomyces cerevisiae strains to modify ethanol yields.  

PubMed

The ability of Saccharomyces cerevisiae to efficiently produce high levels of ethanol through glycolysis has been the focus of much scientific and industrial activity. Despite the accumulated knowledge regarding glycolysis, the modification of flux through this pathway to modify ethanol yields has proved difficult. Here, we report on the systematic screening of 66 strains with deletion mutations of genes encoding enzymes involved in central carbohydrate metabolism for altered ethanol yields. Five of these strains showing the most prominent changes in carbon flux were selected for further investigation. The genes were representative of trehalose biosynthesis (TPS1, encoding trehalose-6-phosphate synthase), central glycolysis (TDH3, encoding glyceraldehyde-3-phosphate dehydrogenase), the oxidative pentose phosphate pathway (ZWF1, encoding glucose-6-phosphate dehydrogenase), and the tricarboxylic acid (TCA) cycle (ACO1 and ACO2, encoding aconitase isoforms 1 and 2). Two strains exhibited lower ethanol yields than the wild type (tps1? and tdh3?), while the remaining three showed higher ethanol yields. To validate these findings in an industrial yeast strain, the TPS1 gene was selected as a good candidate for genetic modification to alter flux to ethanol during alcoholic fermentation in wine. Using low-strength promoters active at different stages of fermentation, the expression of the TPS1 gene was slightly upregulated, resulting in a decrease in ethanol production and an increase in trehalose biosynthesis during fermentation. Thus, the mutant screening approach was successful in terms of identifying target genes for genetic modification in commercial yeast strains with the aim of producing lower-ethanol wines. PMID:23793638

Rossouw, D; Heyns, E H; Setati, M E; Bosch, S; Bauer, F F

2013-09-01

415

Functional Implications and Ubiquitin-Dependent Degradation of the Peptide Transporter Ptr2 in Saccharomyces cerevisiae.  

PubMed

The peptide transporter Ptr2 plays a central role in di- or tripeptide import in Saccharomyces cerevisiae. Although PTR2 transcription has been extensively analyzed in terms of upregulation by the Ubr1-Cup9 circuit, the structural and functional information for this transporter is limited. Here we identified 14 amino acid residues required for peptide import through Ptr2 based on the crystallographic information of Streptococcus thermophilus peptide transporter PepTst and based on the conservation of primary sequences among the proton-dependent oligopeptide transporters (POTs). Expression of Ptr2 carrying one of the 14 mutations of which the corresponding residues of PepTst are involved in peptide recognition, salt bridge interaction, or peptide translocation failed to enable ptr2?trp1 cell growth in alanyl-tryptophan (Ala-Trp) medium. We observed that Ptr2 underwent rapid degradation after cycloheximide treatment (half-life, approximately 1 h), and this degradation depended on Rsp5 ubiquitin ligase. The ubiquitination of Ptr2 most likely occurs at the N-terminal lysines 16, 27, and 34. Simultaneous substitution of arginine for the three lysines fully prevented Ptr2 degradation. Ptr2 mutants of the presumed peptide-binding site (E92Q, R93K, K205R, W362L, and E480D) exhibited severe defects in peptide import and were subjected to Rsp5-dependent degradation when cells were moved to Ala-Trp medium, whereas, similar to what occurs in the wild-type Ptr2, mutant proteins of the intracellular gate were upregulated. These results suggest that Ptr2 undergoes quality control and the defects in peptide binding and the concomitant conformational change render Ptr2 subject to efficient ubiquitination and subsequent degradation. PMID:25172766

Kawai, Ken; Moriya, Atsuto; Uemura, Satoshi; Abe, Fumiyoshi

2014-11-01

416

Intergenic Transcriptional Interference Is Blocked by RNA Polymerase III Transcription Factor TFIIIB in Saccharomyces cerevisiae  

PubMed Central

The major function of eukaryotic RNA polymerase III is to transcribe transfer RNA, 5S ribosomal RNA, and other small non-protein-coding RNA molecules. Assembly of the RNA polymerase III complex on chromosomal DNA requires the sequential binding of transcription factor complexes TFIIIC and TFIIIB. Recent evidence has suggested that in addition to producing RNA transcripts, chromatin-assembled RNA polymerase III complexes may mediate additional nuclear functions that include chromatin boundary, nucleosome phasing, and general genome organization activities. This study provides evidence of another such “extratranscriptional” activity of assembled RNA polymerase III complexes, which is the ability to block progression of intergenic RNA polymerase II transcription. We demonstrate that the RNA polymerase III complex bound to the tRNA gene upstream of the Saccharomyces cerevisiae ATG31 gene protects the ATG31 promoter against readthrough transcriptional interference from the upstream noncoding intergenic SUT467 transcription unit. This protection is predominately mediated by binding of the TFIIIB complex. When TFIIIB binding to this tRNA gene is weakened, an extended SUT467–ATG31 readthrough transcript is produced, resulting in compromised ATG31 translation. Since the ATG31 gene product is required for autophagy, strains expressing the readthrough transcript exhibit defective autophagy induction and reduced fitness under autophagy-inducing nitrogen starvation conditions. Given the recent discovery of widespread pervasive transcription in all forms of life, protection of neighboring genes from intergenic transcriptional interference may be a key extratranscriptional function of assembled RNA polymerase III complexes and possibly other DNA binding proteins. PMID:24336746

Korde, Asawari; Rosselot, Jessica M.; Donze, David

2014-01-01

417

Biodiversity of Saccharomyces cerevisiae populations in Malbec vineyards from the "Zona Alta del Río Mendoza" region in Argentina.  

PubMed

The "Zona Alta del Río Mendoza" (ZARM) is the major Malbec grape viticulture region of Argentina. The aim of the present study was to explore Saccharomyces cerevisiae biodiversity in ZARM vineyards. Interdelta PCR and RFLP mtDNA molecular markers were applied to differentiate S. cerevisiae strains. The presence of commercial strains on ZARM vineyards was also assessed. Our results reveal a highly diverse, but genetically closely related, S. cerevisiae population (containing more than 190 molecular patterns among 590 S. cerevisiae isolates). According to the S. cerevisiae strain diversity found in vineyards, they were classified as vineyards with high and low polymorphic S. cerevisiae populations. Six vineyards showed a high polymorphic population, with more than 20 different S. cerevisiae molecular patterns. S. cerevisiae populations in these vineyards were diverse and irregularly distributed, with different strains in each vineyard site. Low polymorphic S. cerevisiae population vineyards displayed very low yeast diversity, with only 9 to 10 different S. cerevisiae strains and presence of two commercial strains widely distributed. Population diversity estimators were calculated to determine the population structure of S. cerevisiae in the ZARM vineyards. The obtained values support the hypothesis that the eight sampled subpopulations come indeed from a larger population. PMID:22056145

Mercado, Laura; Sturm, María Elena; Rojo, María Cecilia; Ciklic, Iván; Martínez, Claudio; Combina, Mariana

2011-12-15

418

Determination of ethanol in whey-sugar solutions by freezing. [Kluyveromyces fragilis and Saccharomyces cerevisiae  

SciTech Connect

The composition of solutions undergoing yeast fermentation was stimulated by using direct-acid-set cottage cheese whey containing increasing amounts of EtOH (0 to 5.4%) with decreasing amounts of sucrose (10 to 0%). Each decrease of 0.54 g EtOH decreased specific gravity by 0.0046 unit and lowered the freezing point by 0.159 H (the Hortvet unit). Whey containing 10% added sucrose was treated as follows: (a) inoculated with Kluyveromyces fragilis, (b) carbohydrate splitting enzymes added and inoculated with Kluyveromyces fragilis and (c) carbohydrate splitting enzymes added and inoculated with Saccharomyces cerevisiae. All mixtures were incubated 48 h at 32 degrees during which 6 samples from each treatment were analyzed for total solids, specific gravity and freezing point. No difference was noted between samples treated with enzymes or those treated with the 2 yeasts cultured as related to decrease in total solids concentration or specific gravity. Each 0.001 H decrease in freezing point was accompanied by a total solids decrease of 0.006 g/100 g whey in the nonenzyme treated sample, and 0.008 g and 0.010 g/100 g whey in the enzyme-treated samples inoculated with Kluyveromyces fragilis and Saccharomyces cerevisiae, respectively. Each 0.001 H change in freezing point was equivalent to a change of 0.00003 specific gravity unit in the nonenzyme-treated sample and 0.000043 and 0.000048 specific gravity unit in the enzyme-treated samples inoculated with Kluyveromyces fragilis and Saccharomyces cerevisiae, respectively. The precision with which freezing point can be determined suggests its use in evaluating the amount of EtOH produced during fermentation.

Demott, B.J.

1982-01-01

419

Saccharomyces cerevisiae GTPase complex: Gtr1p-Gtr2p regulates cell-proliferation through Saccharomyces cerevisiae Ran-binding protein, Yrb2p  

SciTech Connect

A Gtr1p GTPase, the GDP mutant of which suppresses both temperature-sensitive mutants of Saccharomyces cerevisiae RanGEF/Prp20p and RanGAP/Rna1p, was presently found to interact with Yrb2p, the S. cerevisiae homologue of mammalian Ran-binding protein 3. Gtr1p bound the Ran-binding domain of Yrb2p. In contrast, Gtr2p, a partner of Gtr1p, did not bind Yrb2p, although it bound Gtr1p. A triple mutant: yrb2{delta} gtr1{delta} gtr2{delta} was lethal, while a double mutant: gtr1{delta} gtr2{delta} survived well, indicating that Yrb2p protected cells from the killing effect of gtr1{delta} gtr2{delta}. Recombinant Gtr1p and Gtr2p were purified as a complex from Escherichia coli. The resulting Gtr1p-Gtr2p complex was comprised of an equal amount of Gtr1p and Gtr2p, which inhibited the Rna1p/Yrb2 dependent RanGAP activity. Thus, the Gtr1p-Gtr2p cycle was suggested to regulate the Ran cycle through Yrb2p.

Wang Yonggang [Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582 (Japan); Nakashima, Nobutaka [Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582 (Japan); Sekiguchi, Takeshi [Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582 (Japan)]. E-mail: sekigu@molbiol.med.kyushu-u.ac.jp; Nishimoto, Takeharu [Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582 (Japan)

2005-10-21

420

Multiple Pathways of Recombination Induced by Double-Strand Breaks in Saccharomyces cerevisiae  

PubMed Central

The budding yeast Saccharomyces cerevisiae has been the principal organism used in experiments to examine genetic recombination in eukaryotes. Studies over the past decade have shown that meiotic recombination and probably most mitotic recombination arise from the repair of double-strand breaks (DSBs). There are multiple pathways by which such DSBs can be repaired, including several homologous recombination pathways and still other nonhomologous mechanisms. Our understanding has also been greatly enriched by the characterization of many proteins involved in recombination and by insights that link aspects of DNA repair to chromosome replication. New molecular models of DSB-induced gene conversion are presented. This review encompasses these different aspects of DSB-induced recombination in Saccharomyces and attempts to relate genetic, molecular biological, and biochemical studies of the processes of DNA repair and recombination. PMID:10357855

Paques, Frederic; Haber, James E.

1999-01-01

421

Assembly of bacteriophage Qbeta virus-like particles in yeast Saccharomyces cerevisiae and Pichia pastoris.  

PubMed

Recombinant bacteriophage Qbeta coat protein (CP), which has been proposed as a promising carrier of foreign epitopes via their incorporation either by gene engineering techniques or by chemical coupling, efficiently self-assembles into virus-like particles (VLPs) when expressed in Escherichia coli. Here, we demonstrate expression and self-assembly of Qbeta CP in yeast Saccharomyces cerevisiae and Pichia pastoris. Production reached 3-4 mg/1g of wet cells for S. cerevisiae and 4-6 mg for P. pastoris, which was about 15-20% and 20-30% of the E. coli expression level, respectively. Qbeta VLPs were easily purified by size-exclusion chromatography in both cases and contained nucleic acid, shown by native agarose gel electrophoresis. The obtained particles were highly immunogenic in mice and the resulting sera recognized both E. coli- and yeast-derived Qbeta VLPs equally well. PMID:16406160

Freivalds, Janis; Dislers, Andris; Ose, Velta; Skrastina, Dace; Cielens, Indulis; Pumpens, Paul; Sasnauskas, Kestutis; Kazaks, Andris

2006-05-29

422

Cu,Zn-superoxide dismutase is necessary for proper function of VDAC in Saccharomyces cerevisiae cells.  

PubMed

Available data suggest that a copper-and zinc-containing dismutase (CuZnSOD) plays a significant role in protecting eukaryotic cells against oxidative modifications which may contribute to cell aging. Here we demonstrated that depletion of CuZnSOD in Saccharomyces cerevisiae cells (Deltasod1 cells) affected distinctly channel activity of VDAC (voltage dependent anion selective channel) and resulted in a moderate reduction in VDAC levels as well as in levels of protein crucial for VDAC import into mitochondria, namely Tob55/Sam50 and Tom40. The observed alterations may result in mitochondriopathy and subsequently in the shortening of the replicative life span observed for S. cerevisiaeDeltasod1 cells. PMID:19116152

Karachitos, Andonis; Galganska, Hanna; Wojtkowska, Malgorzata; Budzinska, Malgorzata; Stobienia, Olgierd; Bartosz, Grzegorz; Kmita, Hanna

2009-01-22

423

Molecular mechanisms of Saccharomyces cerevisiae stress adaptation and programmed cell death in response to acetic acid  

PubMed Central

Beyond its classical biotechnological applications such as food and beverage production or as a cell factory, the yeast Saccharomyces cerevisiae is a valuable model organism to study fundamental mechanisms of cell response to stressful environmental changes. Acetic acid is a physiological product of yeast fermentation and it is a well-known food preservative due to its antimicrobial action. Acetic acid has recently been shown to cause yeast cell death and aging. Here we shall focus on the molecular mechanisms of S. cerevisiae stress adaptation and programmed cell death in response to acetic acid. We shall elaborate on the intracellular signaling pathways involved in the cross-talk of pro-survival and pro-death pathways underlying the importance of understanding fundamental aspects of yeast cell homeostasis to improve the performance of a given yeast strain in biotechnological applications. PMID:23430312

Giannattasio, Sergio; Guaragnella, Nicoletta; Zdralevic, Masa; Marra, Ersilia

2013-01-01

424

Three gene expression vector sets for concurrently expressing multiple genes in Saccharomyces cerevisiae.  

PubMed

Yeast has the potential to be used in bulk-scale fermentative production of fuels and chemicals due to its tolerance for low pH and robustness for autolysis. However, expression of multiple external genes in one host yeast strain is considerably labor-intensive due to the lack of polycistronic transcription. To promote the metabolic engineering of yeast, we generated systematic and convenient genetic engineering tools to express multiple genes in Saccharomyces cerevisiae. We constructed a series of multi-copy and integration vector sets for concurrently expressing two or three genes in S. cerevisiae by embedding three classical promoters. The comparative expression capabilities of the constructed vectors were monitored with green fluorescent protein, and the concurrent expression of genes was monitored with three different fluorescent proteins. Our multiple gene expression tool will be helpful to the advanced construction of genetically engineered yeast strains in a variety of research fields other than metabolic engineering. PMID:24447461

Ishii, Jun; Kondo, Takashi; Makino, Harumi; Ogura, Akira; Matsuda, Fumio; Kondo, Akihiko

2014-05-01

425

Involvement of heme biosynthesis in control of sterol uptake by Saccharomyces cerevisiae.  

PubMed Central

Wild-type Saccharomyces cerevisiae do not accumulate exogenous sterols under aerobic conditions, and a mutant allele conferring sterol auxotrophy (erg7) could be isolated only in strains with a heme deficiency. delta-Aminolevulinic acid (ALA) fed to a hem1 (ALA synthetase-) erg7 (2,3-oxidosqualene cyclase-) sterol-auxotrophic strain of S. cerevisiae inhibited sterol uptake, and growth was negatively affected when intracellular sterol was depleted. The inhibition of sterol uptake (and growth of sterol auxotrophs) by ALA was dependent on the ability to synthesize heme from ALA. A procedure was developed which allowed selection of strains which would take up exogenous sterols but had no apparent defect in heme or ergosterol biosynthesis. One of these sterol uptake control mutants possessed an allele which allowed phenotypic expression of sterol auxotrophy in a heme-competent background. PMID:3891725

Lewis, T A; Taylor, F R; Parks, L W

1985-01-01

426

Determination of the intracellular concentration of ethanol in Saccharomyces cerevisiae during fermentation  

SciTech Connect

Considerable controversy exists concerning the intracellular concentration of ethanol in Saccharomyces cerevisiae during fermentation. This controversy results from problems in the measurement of the intracellular concentration of compounds like ethanol, which are being produced rapidly by metabolism and potentially diffuse rapidly from the cell. A new method was used for the determination of intracellular ethanol based on the exclusion of (/sup 14/C)sorbitol to estimate the aqueous cell volume. This method avoided many of the technical problems in previous reports. Results indicate that the intracellular concentrations of ethanol in fermenting suspension of S. cerevisiae are less than or equal to those in the extracellular environment and do not increase to the high levels previously reported even during the most active stages of batch fermentation.

Dombek, K.M.; Ingram, L.O.

1986-01-01

427

Chemical evaluation of white wines elaborated with a recombinant Saccharomyces cerevisiae strain overproducing mannoproteins.  

PubMed

In this study, a recombinant Saccharomyces cerevisiae strain EKD13 overproducing mannoproteins has been used to obtain Albariño white wines. The inoculated strain prevailed and produced complete fermentation of the must, as also occurred in the case of spontaneous (non-inoculated) fermentation and in the must inoculated with the S. cerevisiae EC1118 strain. The analytical study of the wines obtained showed that the most important chemical differences among the wines produced with EKD-13, corresponded to the high concentration of mannoproteins, 2-phenyl ethanol and tyrosol. These differences were attributed to the expression, during must fermentation, of genes modified in the recombinant EKD-13 strain. The results obtained imply that this strain could be potentially useful to produce wines rich in mannoproteins that have distinctive characteristics compared to other similar wines, modifying the sensorial and technological parameters of the wines obtained. PMID:24206689

Juega, M; Gonzalez-Ramos, D; Bartolome, B; Carrascosa, A V; Martinez-Rodriguez, A J

2014-03-15

428

Arrangement of genes TRP1 and TRP3 of Saccharomyces cerevisiae strains.  

PubMed

The tryptophan biosynthetic genes TRP1 and TRP3 and partly also TRP2 and TRP4 have been compared by the technique of Southern hybridization and enzyme measurements in twelve wild isolates of Saccharomyces cerevisiae from natural sources of different continents, in the commonly used laboratory strain S. cerevisiae X2180-1A and in a Kluyveromyces marxianus strain. We could classify these strains into four groups, which did not correlate with their geographical distribution. In no case are the TRP3 and TRP1 genes fused as has been found in other ascomycetes. Two strains were found which, in contrast to strain X2180-1A, show derepression of gene TRP1. Two examples are discussed to demonstrate the usefulness of Southern hybridizations for the identification of closely related strains. PMID:2998296

Braus, G; Furter, R; Prantl, F; Niederberger, P; Hütter, R

1985-09-01

429

Heterologous protein production from the inducible MET25 promoter in Saccharomyces cerevisiae.  

PubMed

Heterologous protein production late in Saccharomyces cerevisiae fermentations is often desirable because it may help avoid the unintentional selection of more rapidly growing, non-protein-expressing cells or allow for the expression of toxic proteins. Here, we describe the use of the MET25 promoter for the production of human serum albumin (HSA) and HSA-fusion proteins in S. cerevisiae. In media lacking methionine, the MET25 promoter yielded high expression levels of HSA and HSA fused to human glucagon, human growth hormone, human interferon alpha, and human interleukin-2. More importantly, we have shown that this system can be used to delay heterologous protein production until late log phase of the growth of the culture and does not require the addition of an exogenous inducer. PMID:15801808

Solow, Steven P; Sengbusch, Jennifer; Laird, Michael W

2005-01-01

430

Cloning and Expression of a Schwanniomyces occidentalis ?-Amylase Gene in Saccharomyces cerevisiae  

PubMed Central

An ?-amylase gene (AMY) was cloned from Schwanniomyces occidentalis CCRC 21164 into Saccharomyces cerevisiae AH22 by inserting Sau3AI-generated DNA fragments into the BamHI site of YEp16. The 5-kilobase insert was shown to direct the synthesis of ?-amylase. After subclones containing various lengths of restricted fragments were screened, a 3.4-kilobase fragment of the donor strain DNA was found to be sufficient for ?-amylase synthesis. The concentration of ?-amylase in culture broth produced by the S. cerevisiae transformants was about 1.5 times higher than that of the gene donor strain. The secreted ?-amylase was shown to be indistinguishable from that of Schwanniomyces occidentalis on the basis of molecular weight and enzyme properties. Images PMID:16348077

Wang, Tsung Tsan; Lin, Long Liu; Hsu, Wen Hwei

1989-01-01

431

Lead sulfide nanoparticles increase cell wall chitin content and induce apoptosis in Saccharomyces cerevisiae.  

PubMed

Although there have been numerous studies on bacterial toxicity, the cytotoxicity of nanoparticles toward fungi remains poorly understood. We investigated the toxicity of various sizes of lead sulfide particles against the important model fungus, Saccharomyces cerevisiae. The smallest particle exerted the highest toxicity, inhibiting cell growth and decreasing cell viability, likely reflecting reduced sedimentation and persistent cell wall attack. In response to cell wall stress, S. cerevisiae showed an increase in the cell wall chitin content and the overexpression of FKS2 and PRM5, two genes of the cell wall integrity signaling pathway. Cell wall stress increased the concentration of intracellular reactive oxygen species, leading to mitochondrial dysfunction and cell apoptosis. The contribution of dissolved lead ions to the overall toxicity was negligible. These findings provide the first demonstration of the physiological protective response of a fungus toward nanoparticles, thereby contributing useful information to the assessment of the environmental impact of metal nanoparticles. PMID:24704549

Sun, Meiqing; Yu, Qilin; Hu, Mengyuan; Hao, Zhenwei; Zhang, Chengdong; Li, Mingchun

2014-05-30

432

The Bioconversion of Red Ginseng Ethanol Extract into Compound K by Saccharomyces cerevisiae HJ-014.  

PubMed

A ?-glucosidase producing yeast strain was isolated from Korean traditional rice wine. Based on the sequence of the YCL008c gene and analysis of the fatty acid composition, the isolate was identified as Saccharomyces cerevisiae strain HJ-014. S. cerevisiae HJ-014 produced ginsenoside Rd, F2, and compound K from the ethanol extract of red ginseng. The production was increased by shaking culture, where the bioconversion efficiency was increased 2-fold compared to standing culture. The production of ginsenoside F2 and compound K was time-dependent and thought to proceed by the transformation pathway of: red ginseng extract?Rd?F2?compound K. The optimum incubation time and concentration of red ginseng extract for the production of compound K was 96 hr and 4.5% (w/v), respectively. PMID:25346602

Choi, Hak Joo; Kim, Eun A; Kim, Dong Hee; Shin, Kwang-Soo

2014-09-01

433

Z curve theory-based analysis of the dynamic nature of nucleosome positioning in Saccharomyces cerevisiae.  

PubMed

Nucleosome is the elementary structural unit of eukaryotic chromatin. Instability of nucleosome positioning plays critical roles in chromatin remodeling in differentiation and disease. In this study, we investigated nucleosome dynamics in the Saccharomyces cerevisiae genome using a geometric model based on Z curve theory. We identified 52,941 stable nucleosomes and 7607 dynamic nucleosomes, compiling them into a genome-wide nucleosome dynamic positioning map and constructing a user-friendly visualization platform (http://bioinfo.hrbmu.edu.cn/nucleosome). Our approach achieved a sensitivity of 90.31% and a specificity of 87.76% for S. cerevisiae. Analysis revealed transcription factor binding sites (TFBSs) were enriched in linkers. And among the sparse nucleosomes around TFBSs, dynamic nucleosomes were slightly preferred. Gene Ontology (GO) enrichment analysis indicated that stable and dynamic nucleosomes were enriched on genes involved in different biological processes and functions. This study provides an approach for comprehending chromatin remodeling and transcriptional regulation of genes. PMID:23958656

Wu, Xueting; Liu, Hui; Liu, Hongbo; Su, Jianzhong; Lv, Jie; Cui, Ying; Wang, Fang; Zhang, Yan

2013-11-01

434

Effects of aeration on formation and localization of the acetyl coenzyme A synthetases of Saccharomyces cerevisiae  

NASA Technical Reports Server (NTRS)

Previous studies on the yeast Saccharomyces cerevisiae have shown that two different forms of the enzyme acetyl coenzyme A synthetase (ACS) are present, depending on the conditions under which the cells are grown. The paper evaluates the usefulness of a method designed to assay both synthetases simultaneously in yeast homogenates. The data presented confirm the possibility of simultaneous detection and estimation of the amount of both ACSs of S. cerevisiae in crude homogenates of this strain, making possible the study of physiological factors involved in the formation of these isoenzymes. One important factor for specifying which of the two enzymes is found in these yeast cells is the presence or absence of oxygen in their environment. Aeration not only affects the ratio of the two ACSs but also appears to affect the cellular distribution of these enzymes. Most of the data presented suggest the possibility that the nonaerobic ACS may serve as a precursor to the aerobic form.

Klein, H. P.; Jahnke, L.

1979-01-01

435

PAD1 and FDC1 are essential for the decarboxylation of phenylacrylic acids in Saccharomyces cerevisiae.  

PubMed

The volatile phenols, to which Saccharomyces cerevisiae converts from phenylacrylic acids including ferulic acid, p-coumaric acid, and cinnamic acid, generate off-flavors in alcoholic beverages such as beer and wine. Using gene disruptants, transformants and cell-free extracts of these strains, we have verified that the adjacent PAD1 (phenylacrylic acid decarboxylase, YDR538W) and FDC1 (ferulic acid decarboxylase, YDR539W) genes are essential for the decarboxylation of phenylacrylic acids in S. cerevisiae. Pad1p and Fdc1p are homologous with UbiX and UbiD, respectively, in the ubiquinone synthetic pathway of Escherichia coli. However, ubiquinone was detected quantitatively in all of the yeast single-deletion mutants, Delta pad1, Delta fdc1, and double-deletion mutant, Delta pad1 Delta fdc1. PMID:20471595

Mukai, Nobuhiko; Masaki, Kazuo; Fujii, Tsutomu; Kawamukai, Makoto; Iefuji, Haruyuki

2010-06-01

436

The Bioconversion of Red Ginseng Ethanol Extract into Compound K by Saccharomyces cerevisiae HJ-014  

PubMed Central

A ?-glucosidase producing yeast strain was isolated from Korean traditional rice wine. Based on the sequence of the YCL008c gene and analysis of the fatty acid composition, the isolate was identified as Saccharomyces cerevisiae strain HJ-014. S. cerevisiae HJ-014 produced ginsenoside Rd, F2, and compound K from the ethanol extract of red ginseng. The production was increased by shaking culture, where the bioconversion efficiency was increased 2-fold compared to standing culture. The production of ginsenoside F2 and compound K was time-dependent and thought to proceed by the transformation pathway of: red ginseng extract?Rd?F2?compound K. The optimum incubation time and concentration of red ginseng extract for the production of compound K was 96 hr and 4.5% (w/v), respectively.

Choi, Hak Joo; Kim, Eun A; Kim, Dong Hee

2014-01-01

437

Mechanisms of strontium uptake by laboratory and brewing strains of Saccharomyces cerevisiae.  

PubMed Central

Laboratory and brewing strains of Saccharomyces cerevisiae were compared for metabolism-independent and -dependent Sr2+ uptake. Cell surface adsorption of Sr2+ to live cells was greater in the brewing than in the laboratory strain examined. However, uptake levels were greater in denatured (dried and ground) S. cerevisiae, and the relative affinities of Sr2+ for the two strains were reversed. Results for the brewing S. cerevisiae strain were similar whether the organism was obtained fresh from brewery waste or after culturing under the same conditions as for the laboratory strain. Reciprocal Langmuir plots of uptake data for live biomass were not linear, whereas those for denatured biomass were. The more complex Sr2+ binding mechanism inferred for live S. cerevisiae was underlined by cation displacement experiments. Sr2+ adsorption to live cells resulted in release of Mg2+, Ca2+, and H+, suggesting a combination of ionic and covalent bonding of Sr2+. In contrast, Mg2+ was the predominant exchangeable cation on denatured biomass, indicating primarily electrostatic attraction of Sr2+. Incubation of live S. cerevisiae in the presence of glucose resulted in a stimulation of Sr2+ uptake. Cell fractionation revealed that this increased Sr2+ uptake was mostly due to sequestration of Sr2+ in the vacuole, although a small increase in cytoplasmic Sr2+ was also evident. No stimulation or inhibition of active H+ efflux resulted from metabolism-dependent Sr2+ accumulation. However, a decline in cytoplasmic, and particularly vacuolar, Mg2+, in comparison with that of cells incubated with Sr2+ in the absence of glucose, was apparent. This was most marked for the laboratory S. cerevisiae strain, which contained higher Mg2+ levels than the brewing strain. PMID:1335718

Avery, S V; Tobin, J M

1992-01-01

438

Fate of highly expressed proteins destined to peroxisomes in Saccharomyces cerevisiae.  

PubMed

Import of proteins into organelles usually requires a cis-acting targeting signal. Analysis of various hybrid proteins, consisting of mouse DHFR and parts of catalase A from Saccharomyces cerevisiae, revealed that fusion proteins containing the N-terminal 126 amino acids, or less, of catalase A remain in the cytosol whereas fusion proteins containing 140, or more, N-terminal amino acids of catalase A form large aggregates inside the cell. These protein bodies, which lack a surrounding membrane, copurified with peroxisomes on cell fractionation. The peroxisomal targeting signal of catalase A does not reside at the C-terminus or at the N-terminus. PMID:2245472

Hartig, A; Ogris, M; Cohen, G; Binder, M

1990-07-01

439

Chitin synthase 2 is essential for septum formation and cell division in Saccharomyces cerevisiae.  

PubMed Central

Previous work led to the puzzling conclusion that chitin synthase 1, the major chitin synthase activity in Saccharomyces cerevisiae, is not required for synthesis of the chitinous primary septum. The mechanism of in vivo synthesis of chitin has now been clarified by cloning the structural gene for the newly found chitin synthase 2, a relatively minor activity in yeast. Disruption of the chitin synthase 2 gene results in the loss of well-defined septa and in growth arrest, establishing that the gene product is essential for both septum formation and cell division. Images PMID:2968606

Silverman, S J; Sburlati, A; Slater, M L; Cabib, E

1988-01-01

440

Chitin synthase 2 is essential for septum formation and cell division in Saccharomyces cerevisiae.  

PubMed

Previous work led to the puzzling conclusion that chitin synthase 1, the major chitin synthase activity in Saccharomyces cerevisiae, is not required for synthesis of the chitinous primary septum. The mechanism of in vivo synthesis of chitin has now been clarified by cloning the structural gene for the newly found chitin synthase 2, a relatively minor activity in yeast. Disruption of the chitin synthase 2 gene results in the loss of well-defined septa and in growth arrest, establishing that the gene product is essential for both septum formation and cell division. PMID:2968606

Silverman, S J; Sburlati, A; Slater, M L; Cabib, E

1988-07-01