Anaerobic growth of Saccharomyces cerevisiae in the absence of oleic acid and ergosterol?

1983 ◽  
Vol 134 (1) ◽  
pp. 64-67 ◽  
Author(s):  
J. M. Macy ◽  
M. W. Miller
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Oleic Acid ◽  
Anaerobic Growth

scholarly journals Regulatory Mechanisms Controlling Expression of the DAN/TIR Mannoprotein Genes During Anaerobic Remodeling of the Cell Wall in Saccharomyces cerevisiae

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1169-1177
Author(s):  
Natalia E Abramova ◽  
Brian D Cohen ◽  
Odeniel Sertil ◽  
Rachna Kapoor ◽  
Kelvin J A Davies ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Consensus Sequence ◽  
Ectopic Expression ◽  
Constitutive Expression ◽  
Anaerobic Growth ◽  
Zinc Cluster ◽  
Sterol Transport ◽  
Genes Encoding ◽  
Altered Regulation ◽  
Repression Domain

Abstract The DAN/TIR genes of Saccharomyces cerevisiae encode homologous mannoproteins, some of which are essential for anaerobic growth. Expression of these genes is induced during anaerobiosis and in some cases during cold shock. We show that several heme-responsive mechanisms combine to regulate DAN/TIR gene expression. The first mechanism employs two repression factors, Mox1 and Mox2, and an activation factor, Mox4 (for mannoprotein regulation by oxygen). The genes encoding these proteins were identified by selecting for recessive mutants with altered regulation of a dan1::ura3 fusion. MOX4 is identical to UPC2, encoding a binucleate zinc cluster protein controlling expression of an anaerobic sterol transport system. Mox4/Upc2 is required for expression of all the DAN/TIR genes. It appears to act through a consensus sequence termed the AR1 site, as does Mox2. The noninducible mox4Δ allele was epistatic to the constitutive mox1 and mox2 mutations, suggesting that Mox1 and Mox2 modulate activation by Mox4 in a heme-dependent fashion. Mutations in a putative repression domain in Mox4 caused constitutive expression of the DAN/TIR genes, indicating a role for this domain in heme repression. MOX4 expression is induced both in anaerobic and cold-shocked cells, so heme may also regulate DAN/TIR expression through inhibition of expression of MOX4. Indeed, ectopic expression of MOX4 in aerobic cells resulted in partially constitutive expression of DAN1. Heme also regulates expression of some of the DAN/TIR genes through the Rox7 repressor, which also controls expression of the hypoxic gene ANB1. In addition Rox1, another heme-responsive repressor, and the global repressors Tup1 and Ssn6 are also required for full aerobic repression of these genes.

Oleic acid and ergosterol supplementation mitigates oxidative stress in wine strains of Saccharomyces cerevisiae

2010 ◽  
Vol 141 (3) ◽  
pp. 229-235 ◽  
Author(s):  
Sara Landolfo ◽  
Giacomo Zara ◽  
Severino Zara ◽  
Marilena Budroni ◽  
Maurizio Ciani ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Saccharomyces Cerevisiae ◽  
Oleic Acid

scholarly journals Influence of the nitrogen source on Saccharomyces cerevisiae anaerobic growth and product formation.

1996 ◽  
Vol 62 (9) ◽  
pp. 3187-3195 ◽  
Author(s):  
E Albers ◽  
C Larsson ◽  
G Lidén ◽  
C Niklasson ◽  
L Gustafsson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nitrogen Source ◽  
Product Formation ◽  
Anaerobic Growth

scholarly journals Molecular Basis for Anaerobic Growth of Saccharomyces cerevisiae on Xylose, Investigated by Global Gene Expression and Metabolic Flux Analysis

2004 ◽  
Vol 70 (4) ◽  
pp. 2307-2317 ◽  
Author(s):  
Marco Sonderegger ◽  
Marie Jeppsson ◽  
Bärbel Hahn-Hägerdal ◽  
Uwe Sauer
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Metabolic Flux Analysis ◽  
Metabolic Flux ◽  
Global Gene Expression ◽  
Anaerobic Growth ◽  
Flux Analysis ◽  
Atp Production ◽  
Redox Imbalance ◽  
Chemostat Cultures

ABSTRACT Yeast xylose metabolism is generally considered to be restricted to respirative conditions because the two-step oxidoreductase reactions from xylose to xylulose impose an anaerobic redox imbalance. We have recently developed, however, a Saccharomyces cerevisiae strain that is at present the only known yeast capable of anaerobic growth on xylose alone. Using transcriptome analysis of aerobic chemostat cultures grown on xylose-glucose mixtures and xylose alone, as well as a combination of global gene expression and metabolic flux analysis of anaerobic chemostat cultures grown on xylose-glucose mixtures, we identified the distinguishing characteristics of this unique phenotype. First, the transcript levels and metabolic fluxes throughout central carbon metabolism were significantly higher than those in the parent strain, and they were most pronounced in the xylose-specific, pentose phosphate, and glycerol pathways. Second, differential expression of many genes involved in redox metabolism indicates that increased cytosolic NADPH formation and NADH consumption enable a higher flux through the two-step oxidoreductase reaction of xylose to xylulose in the mutant. Redox balancing is apparently still a problem in this strain, since anaerobic growth on xylose could be improved further by providing acetoin as an external NADH sink. This improved growth was accompanied by an increased ATP production rate and was not accompanied by higher rates of xylose uptake or cytosolic NADPH production. We concluded that anaerobic growth of the yeast on xylose is ultimately limited by the rate of ATP production and not by the redox balance per se, although the redox imbalance, in turn, limits ATP production.

scholarly journals Synthesis of Polyhydroxyalkanoate in the Peroxisome of Saccharomyces cerevisiae by Using Intermediates of Fatty Acid β-Oxidation

2001 ◽  
Vol 67 (11) ◽  
pp. 5254-5260 ◽  
Author(s):  
Yves Poirier ◽  
Nadine Erard ◽  
Jean MacDonald-Comber Petétot
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Isocitrate Lyase ◽  
Dry Weight ◽  
Pha Synthase ◽  
Recombinant Yeast ◽  
Medium Chain Length ◽  
The Media

ABSTRACT Medium-chain-length polyhydroxyalkanoates (PHAs) are polyesters having properties of biodegradable thermoplastics and elastomers that are naturally produced by a variety of pseudomonads.Saccharomyces cerevisiae was transformed with thePseudomonas aeruginosa PHAC1 synthase modified for peroxisome targeting by the addition of the carboxyl 34 amino acids from the Brassica napus isocitrate lyase. The PHAC1 gene was put under the control of the promoter of the catalase A gene. PHA synthase expression and PHA accumulation were found in recombinantS. cerevisiae growing in media containing fatty acids. PHA containing even-chain monomers from 6 to 14 carbons was found in recombinant yeast grown on oleic acid, while odd-chain monomers from 5 to 15 carbons were found in PHA from yeast grown on heptadecenoic acid. The maximum amount of PHA accumulated was 0.45% of the dry weight. Transmission electron microscopy of recombinant yeast grown on oleic acid revealed the presence of numerous PHA inclusions found within membrane-bound organelles. Together, these data show that S. cerevisiae expressing a peroxisomal PHA synthase produces PHA in the peroxisome using the 3-hydroxyacyl coenzyme A intermediates of the β-oxidation of fatty acids present in the media. S. cerevisiaecan thus be used as a powerful model system to learn how fatty acid metabolism can be modified in order to synthesize high amounts of PHA in eukaryotes, including plants.

scholarly journals Identification and Characterization ofMAE1, the Saccharomyces cerevisiae Structural Gene Encoding Mitochondrial Malic Enzyme

1998 ◽  
Vol 180 (11) ◽  
pp. 2875-2882 ◽  
Author(s):  
Eckhard Boles ◽  
Patricia de Jong-Gubbels ◽  
Jack T. Pronk
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Enzyme Activity ◽  
Pyruvate Kinase ◽  
Malic Enzyme ◽  
Fold Increase ◽  
Growth Conditions ◽  
Anaerobic Growth ◽  
Oxidative Decarboxylation ◽  
Mrna Levels ◽  
Malic Enzyme Activity

ABSTRACT Pyruvate, a precursor for several amino acids, can be synthesized from phosphoenolpyruvate by pyruvate kinase. Nevertheless, pyk1 pyk2 mutants of Saccharomyces cerevisiae devoid of pyruvate kinase activity grew normally on ethanol in defined media, indicating the presence of an alternative route for pyruvate synthesis. A candidate for this role is malic enzyme, which catalyzes the oxidative decarboxylation of malate to pyruvate. Disruption of open reading frame YKL029c, which is homologous to malic enzyme genes from other organisms, abolished malic enzyme activity in extracts of glucose-grown cells. Conversely, overexpression ofYKL029c/MAE1 from the MET25 promoter resulted in an up to 33-fold increase of malic enzyme activity. Growth studies with mutants demonstrated that presence of either Pyk1p or Mae1p is required for growth on ethanol. Mutants lacking both enzymes could be rescued by addition of alanine or pyruvate to ethanol cultures. Disruption of MAE1 alone did not result in a clear phenotype. Regulation of MAE1 was studied by determining enzyme activities and MAE1 mRNA levels in wild-type cultures and by measuring β-galactosidase activities in a strain carrying a MAE1::lacZ fusion. Both in shake flask cultures and in carbon-limited chemostat cultures,MAE1 was constitutively expressed. A three- to fourfold induction was observed during anaerobic growth on glucose. Subcellular fractionation experiments indicated that malic enzyme in S. cerevisiae is a mitochondrial enzyme. Its regulation and localization suggest a role in the provision of intramitochondrial NADPH or pyruvate under anaerobic growth conditions. However, since null mutants could still grow anaerobically, this function is apparently not essential.

scholarly journals Oxygen Consumption by Anaerobic Saccharomyces cerevisiae under Enological Conditions: Effect on Fermentation Kinetics

2003 ◽  
Vol 69 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Eric Rosenfeld ◽  
Bertrand Beauvoit ◽  
Bruno Blondin ◽  
Jean-Michel Salmon
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Oxygen Consumption ◽  
Stationary Phase ◽  
Respiratory Chain ◽  
Unsaturated Fatty Acids ◽  
De Novo ◽  
Anaerobic Growth ◽  
Fermentation Rate ◽  
Fermentation Kinetics ◽  
Oxygen Pulse

ABSTRACT The anaerobic growth of the yeast Saccharomyces cerevisiae normally requires the addition of molecular oxygen, which is used to synthesize sterols and unsaturated fatty acids (UFAs). A single oxygen pulse can stimulate enological fermentation, but the biochemical pathways involved in this phenomenon remain to be elucidated. We showed that the addition of oxygen (0.3 to 1.5 mg/g [dry mass] of yeast) to a lipid-depleted medium mainly resulted in the synthesis of the sterols and UFAs required for cell growth. However, the addition of oxygen during the stationary phase in a medium containing excess ergosterol and oleic acid increased the specific fermentation rate, increased cell viability, and shortened the fermentation period. Neither the respiratory chain nor de novo protein synthesis was required for these medium- and long-term effects. As de novo lipid synthesis may be involved in ethanol tolerance, we studied the effect of oxygen addition on sterol and UFA auxotrophs (erg1 and ole1 mutants, respectively). Both mutants exhibited normal anaerobic fermentation kinetics. However, only the ole1 mutant strain responded to the oxygen pulse during the stationary phase, suggesting that de novo sterol synthesis is required for the oxygen-induced increase of the specific fermentation rate. In conclusion, the sterol pathway appears to contribute significantly to the oxygen consumption capacities of cells under anaerobic conditions. Nevertheless, we demonstrated the existence of alternative oxygen consumption pathways that are neither linked to the respiratory chain nor linked to heme, sterol, or UFA synthesis. These pathways dissipate the oxygen added during the stationary phase, without affecting the fermentation kinetics.

scholarly journals ATPase-based implementation of enforced ATP wasting in Saccharomyces cerevisiae for improved ethanol production

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ahmed Zahoor ◽  
Katrin Messerschmidt ◽  
Simon Boecker ◽  
Steffen Klamt
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Atpase Activity ◽  
Ethanol Production ◽  
Ethanol Yield ◽  
Volumetric Productivity ◽  
Anaerobic Growth ◽  
Control Strain ◽  
Genomic Integration ◽  
Expression Of Genes ◽  
Atp Generation

Abstract Background Enforced ATP wasting has been recognized as a promising metabolic engineering strategy to enhance the microbial production of metabolites that are coupled to ATP generation. It also appears to be a suitable approach to improve production of ethanol by Saccharomyces cerevisiae. In the present study, we constructed different S. cerevisiae strains with heterologous expression of genes of the ATP-hydrolyzing F1-part of the ATPase enzyme to induce enforced ATP wasting and quantify the resulting effect on biomass and ethanol formation. Results In contrast to genomic integration, we found that episomal expression of the αβγ subunits of the F1-ATPase genes of Escherichia coli in S. cerevisiae resulted in significantly increased ATPase activity, while neither genomic integration nor episomal expression of the β subunit from Trichoderma reesei could enhance ATPase activity. When grown in minimal medium under anaerobic growth-coupled conditions, the strains expressing E. coli’s F1-ATPase genes showed significantly improved ethanol yield (increase of 10% compared to the control strain). However, elevated product formation reduces biomass formation and, therefore, volumetric productivity. We demonstrate that this negative effect can be overcome under growth-decoupled (nitrogen-starved) operation with high and constant biomass concentration. Under these conditions, which mimic the second (production) phase of a two-stage fermentation process, the ATPase-expressing strains showed significant improvement in volumetric productivity (up to 111%) compared to the control strain. Conclusions Our study shows that expression of genes of the F1-portion of E. coli’s ATPase induces ATPase activity in S. cerevisiae and can be a promising way to improve ethanol production. This ATP-wasting strategy can be easily applied to other metabolites of interest, whose formation is coupled to ATP generation.

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