Glucosylceramide Contained in Koji Mold-Cultured Cereal Confers Membrane and Flavor Modification and Stress Tolerance to Saccharomyces cerevisiae during Coculture Fermentation

ABSTRACTIn nature, different microorganisms create communities through their physiochemical and metabolic interactions. Many fermenting microbes, such as yeasts, lactic acid bacteria, and acetic acid bacteria, secrete acidic substances and grow faster at acidic pH values. However, on the surface of cereals, the pH is neutral to alkaline. Therefore, in order to grow on cereals, microbes must adapt to the alkaline environment at the initial stage of colonization; such adaptations are also crucial for industrial fermentation. Here, we show that the yeastSaccharomyces cerevisiae, which is incapable of synthesizing glucosylceramide (GlcCer), adapted to alkaline conditions after exposure to GlcCer from koji cereal cultured withAspergillus kawachii. We also show that various species of GlcCer derived from different plants and fungi similarly conferred alkali tolerance to yeast. Although exogenous ceramide also enhanced the alkali tolerance of yeast, no discernible degradation of GlcCer to ceramide was observed in the yeast culture, suggesting that exogenous GlcCer itself exerted the activity. Exogenous GlcCer also increased ethanol tolerance and modified the flavor profile of the yeast cells by altering the membrane properties. These results indicate that GlcCer fromA. kawachiimodifies the physiology of the yeastS. cerevisiaeand demonstrate a new mechanism for cooperation between microbes in food fermentation.

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Pho85 Kinase, a Cyclin-Dependent Kinase, Regulates Nuclear Accumulation of the Rim101 Transcription Factor in the Stress Response of Saccharomyces cerevisiae

Eukaryotic Cell ◽

10.1128/ec.00247-09 ◽

2010 ◽

Vol 9 (6) ◽

pp. 943-951 ◽

Cited By ~ 13

Author(s):

Masafumi Nishizawa ◽

Mirai Tanigawa ◽

Michio Hayashi ◽

Tatsuya Maeda ◽

Yoshiaki Yazaki ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Transcription Factor ◽

Cellular Response ◽

Proteolytic Processing ◽

Yeast Cells ◽

Nuclear Accumulation ◽

Alkaline Stress ◽

Content Type ◽

Its Gene ◽

Alkaline Conditions

ABSTRACT The budding yeast Saccharomyces cerevisiae alters its gene expression profile in response to changing environmental conditions. The Pho85 kinase, one of the yeast cyclin-dependent kinases (CDK), is known to play an important role in the cellular response to alterations in parameters such as nutrient levels and salinity. Several genes whose expression is regulated, either directly or indirectly, by the Rim101 transcription factor become constitutively activated when Pho85 function is absent,. Because Rim101 is responsible for adaptation to alkaline conditions, this observation suggests an interaction between Pho85 and Rim101 in the response to alkaline stress. We have found that Pho85 affects neither RIM101 transcription, the proteolytic processing that is required for Rim101 activation, nor Rim101 stability. Rather, Pho85 regulates the nuclear accumulation of active Rim101, possibly via phosphorylation. Additionally, we report that Pho85 and the transcription factor Pho4 are necessary for adaptation to alkaline conditions and that PTK2 activation by Pho4 is involved in this process. These findings illustrate novel roles for the regulators of the PHO system when yeast cells cope with various environmental stresses potentially threatening their survival.

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Evolution of ethylene by Saccharomyces cerevisiae as influenced by the carbon source for growth and the presence of air

Canadian Journal of Microbiology ◽

10.1139/m78-107 ◽

1978 ◽

Vol 24 (6) ◽

pp. 637-642 ◽

Cited By ~ 6

Author(s):

K. C. Thomas ◽

Mary Spencer

Keyword(s):

Saccharomyces Cerevisiae ◽

Carbon Source ◽

Ethylene Production ◽

Atp Synthesis ◽

Yeast Cells ◽

Yeast Culture ◽

Wild Type ◽

Yeast Saccharomyces Cerevisiae ◽

Absolute Requirement ◽

Wild Type Yeast

Effects of the carbon source and oxygen on ethylene production by the yeast Saccharomyces cerevisiae have been studied. The amounts of ethylene evolved by the yeast culture were less than those detected in the blank (an equal volume of uninoculated medium), suggesting a net absorption of ethylene by the yeast cells. Addition of glucose to the lactate-grown yeast culture induced ethylene production. This glucose-induced stimulation of ethylene production was inhibited to a great extent by cycloheximide. Results suggested that the yeast cells in the presence of glucose synthesized an ethylene precursor and passed it into the medium. The conversion of this precursor to ethylene might be stimulated by oxygen. The fact that ethylene was produced by the yeast growing anaerobically and also by respiration-deficient mutants isolated from the wild-type yeast suggested that mitochondrial ATP synthesis was not an absolute requirement for ethylene biogenesis.

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Determination of the Global Pattern of Gene Expression in Yeast Cells by Intracellular Levels of Guanine Nucleotides

mBio ◽

10.1128/mbio.02500-18 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 3

Author(s):

Andy Hesketh ◽

Marta Vergnano ◽

Stephen G. Oliver

Keyword(s):

Gene Expression ◽

Saccharomyces Cerevisiae ◽

Carbon Source ◽

Gene Transcription ◽

Adenine Nucleotide ◽

High Energy ◽

Yeast Cells ◽

Purine Nucleotides ◽

Global Pattern ◽

Content Type

ABSTRACT Correlations between gene transcription and the abundance of high-energy purine nucleotides in Saccharomyces cerevisiae have often been noted. However, there has been no systematic investigation of this phenomenon in the absence of confounding factors such as nutrient status and growth rate, and there is little hard evidence for a causal relationship. Whether transcription is fundamentally responsive to prevailing cellular energetic conditions via sensing of intracellular purine nucleotides, independently of specific nutrition, remains an important question. The controlled nutritional environment of chemostat culture revealed a strong correlation between ATP and GTP abundance and the transcription of genes required for growth. Short pathways for the inducible and futile consumption of ATP or GTP were engineered into S. cerevisiae, permitting analysis of the transcriptional effect of an increased demand for these nucleotides. During steady-state growth using the fermentable carbon source glucose, the futile consumption of ATP led to a decrease in intracellular ATP concentration but an increase in GTP and the guanylate energy charge (GEC). Expression of transcripts encoding proteins involved in ribosome biogenesis, and those controlled by promoters subject to SWI/SNF-dependent chromatin remodelling, was correlated with these nucleotide pool changes. Similar nucleotide abundance changes were observed using a nonfermentable carbon source, but an effect on the growth-associated transcriptional programme was absent. Induction of the GTP-cycling pathway had only marginal effects on nucleotide abundance and gene transcription. The transcriptional response of respiring cells to glucose was dampened in chemostats induced for ATP cycling, but not GTP cycling, and this was primarily associated with altered adenine nucleotide levels. IMPORTANCE This paper investigates whether, independently of the supply of any specific nutrient, gene transcription responds to the energy status of the cell by monitoring ATP and GTP levels. Short pathways for the inducible and futile consumption of ATP or GTP were engineered into the yeast Saccharomyces cerevisiae, and the effect of an increased demand for these purine nucleotides on gene transcription was analyzed. The resulting changes in transcription were most consistently associated with changes in GTP and GEC levels, although the reprogramming in gene expression during glucose repression is sensitive to adenine nucleotide levels. The results show that GTP levels play a central role in determining how genes act to respond to changes in energy supply and that any comprehensive understanding of the control of eukaryotic gene expression requires the elucidation of how changes in guanine nucleotide abundance are sensed and transduced to alter the global pattern of transcription.

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Sml1 Inhibits the DNA Repair Activity of Rev1 in Saccharomyces cerevisiae during Oxidative Stress

Applied and Environmental Microbiology ◽

10.1128/aem.02838-19 ◽

2020 ◽

Vol 86 (7) ◽

Author(s):

Rui Yao ◽

Pei Zhou ◽

Chengjin Wu ◽

Liming Liu ◽

Jing Wu

Keyword(s):

Oxidative Stress ◽

Saccharomyces Cerevisiae ◽

Dna Damage ◽

Survival Rate ◽

Type Strain ◽

Mutation Frequency ◽

Wild Type Strain ◽

Yeast Cells ◽

Wild Type ◽

Content Type

ABSTRACT In Saccharomyces cerevisiae, Y family DNA polymerase Rev1 is involved in the repair of DNA damage by translesion DNA synthesis (TLS). In the current study, to elucidate the role of Rev1 in oxidative stress-induced DNA damage in S. cerevisiae, REV1 was deleted and overexpressed; transcriptome analysis of these mutants along with the wild-type strain was performed to screen potential genes that could be associated with REV1 during response to DNA damage. When the yeast cells were treated with 2 mM H2O2, the deletion of REV1 resulted in a 1.5- and 2.8-fold decrease in the survival rate and mutation frequency, respectively, whereas overexpression of REV1 increased the survival rate and mutation frequency by 1.1- and 2.9-fold, respectively, compared to the survival rate and mutation frequency of the wild-type strain. Transcriptome and phenotypic analyses identified that Sml1 aggravated oxidative stress in the yeast cells by inhibiting the activity of Rev1. This inhibition was due to the physical interaction between the BRCA1 C terminus (BRCT) domain of Rev1 and amino acid residues 36 to 70 of Sml1; the cell survival rate and mutation frequency increased by 1.8- and 3.1-fold, respectively, when this interaction was blocked. We also found that Sml1 inhibited Rev1 phosphorylation under oxidative stress and that deletion of SML1 increased the phosphorylation of Rev1 by 46%, whereas overexpression of SML1 reduced phosphorylation of Rev1. Overall, these findings demonstrate that Sml1 could be a novel regulator that mediates Rev1 dephosphorylation to inhibit its activity during oxidative stress. IMPORTANCE Rev1 was critical for cell growth in S. cerevisiae, and the deletion of REV1 caused a severe growth defect in cells exposed to oxidative stress (2 mM H2O2). Furthermore, we found that Sml1 physically interacted with Rev1 and inhibited Rev1 phosphorylation, thereby inhibiting Rev1 DNA antioxidant activity. These findings indicate that Sml1 could be a novel regulator for Rev1 in response to DNA damage by oxidative stress.

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Coordinated Hsp110 and Hsp104 Activities Power Protein Disaggregation in Saccharomyces cerevisiae

Molecular and Cellular Biology ◽

10.1128/mcb.00027-17 ◽

2017 ◽

Vol 37 (11) ◽

Cited By ~ 26

Author(s):

Jayasankar Mohanakrishnan Kaimal ◽

Ganapathi Kandasamy ◽

Fabian Gasser ◽

Claes Andréasson

Keyword(s):

Saccharomyces Cerevisiae ◽

Heat Shock ◽

Protein Aggregation ◽

Yeast Cells ◽

Eukaryotic Cells ◽

Content Type ◽

Dependent Protein ◽

And Function ◽

Cellular Dysfunction

ABSTRACT Protein aggregation is intimately associated with cellular stress and is accelerated during aging, disease, and cellular dysfunction. Yeast cells rely on the ATP-consuming chaperone Hsp104 to disaggregate proteins together with Hsp70. Hsp110s are ancient and abundant chaperones that form complexes with Hsp70. Here we provide in vivo data showing that the Saccharomyces cerevisiae Hsp110s Sse1 and Sse2 are essential for Hsp104-dependent protein disaggregation. Following heat shock, complexes of Hsp110 and Hsp70 are recruited to protein aggregates and function together with Hsp104 in the disaggregation process. In the absence of Hsp110, targeting of Hsp70 and Hsp104 to the aggregates is impaired, and the residual Hsp104 that still reaches the aggregates fails to disaggregate. Thus, coordinated activities of both Hsp104 and Hsp110 are required to reactivate aggregated proteins. These findings have important implications for the understanding of how eukaryotic cells manage misfolded and amyloid proteins.

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Soybean Ferritin Expression in Saccharomyces cerevisiae Modulates Iron Accumulation and Resistance to Elevated Iron Concentrations

Applied and Environmental Microbiology ◽

10.1128/aem.00305-16 ◽

2016 ◽

Vol 82 (10) ◽

pp. 3052-3060 ◽

Cited By ~ 3

Author(s):

Rosa de Llanos ◽

Carlos Andrés Martínez-Garay ◽

Josep Fita-Torró ◽

Antonia María Romero ◽

María Teresa Martínez-Pastor ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Iron Deficiency ◽

Iron Metabolism ◽

Soybean Seed ◽

Iron Accumulation ◽

Yeast Cells ◽

Nutritional Disorder ◽

Iron Storage ◽

Content Type ◽

Iron Concentrations

ABSTRACTFungi, including the yeastSaccharomyces cerevisiae, lack ferritin and use vacuoles as iron storage organelles. This work explored how plant ferritin expression influenced baker's yeast iron metabolism. Soybean seed ferritin H1 (SFerH1) and SFerH2 genes were cloned and expressed in yeast cells. Both soybean ferritins assembled as multimeric complexes, which bound yeast intracellular ironin vivoand, consequently, induced the activation of the genes expressed during iron scarcity. Soybean ferritin protected yeast cells that lacked the Ccc1 vacuolar iron detoxification transporter from toxic iron levels by reducing cellular oxidation, thus allowing growth at high iron concentrations. Interestingly, when simultaneously expressed inccc1Δ cells, SFerH1 and SFerH2 assembled as heteropolymers, which further increased iron resistance and reduced the oxidative stress produced by excess iron compared to ferritin homopolymer complexes. Finally, soybean ferritin expression led to increased iron accumulation in both wild-type andccc1Δ yeast cells at certain environmental iron concentrations.IMPORTANCEIron deficiency is a worldwide nutritional disorder to which women and children are especially vulnerable. A common strategy to combat iron deficiency consists of dietary supplementation with inorganic iron salts, whose bioavailability is very low. Iron-enriched yeasts and cereals are alternative strategies to diminish iron deficiency. Animals and plants possess large ferritin complexes that accumulate, detoxify, or buffer excess cellular iron. However, the yeastSaccharomyces cerevisiaelacks ferritin and uses vacuoles as iron storage organelles. Here, we explored how soybean ferritin expression influenced yeast iron metabolism, confirming that yeasts that express soybean seed ferritin could be explored as a novel strategy to increase dietary iron absorption.

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Shedding Light on the Formation and Structure of Kombucha Biofilm Using Two-Photon Fluorescence Microscopy

Frontiers in Microbiology ◽

10.3389/fmicb.2021.725379 ◽

2021 ◽

Vol 12 ◽

Author(s):

Thierry Tran ◽

Cosette Grandvalet ◽

Pascale Winckler ◽

François Verdier ◽

Antoine Martin ◽

...

Keyword(s):

De Novo ◽

Acetic Acid Bacteria ◽

Spatial Optimization ◽

Microbial Interactions ◽

Yeast Cells ◽

Two Photon Microscopy ◽

Two Photon ◽

Metabolic Interactions ◽

Two Photon Fluorescence ◽

The Impact

Kombucha pellicles are often used as inoculum to produce this beverage and have become a signature feature. This cellulosic biofilm produced by acetic acid bacteria (AAB) involves yeasts, which are also part of the kombucha consortia. The role of microbial interactions in the de novo formation and structure of kombucha pellicles was investigated during the 3 days following inoculation, using two-photon microscopy coupled with fluorescent staining. Aggregated yeast cells appear to serve as scaffolding to which bacterial cellulose accumulates. This initial foundation leads to a layered structure characterized by a top cellulose-rich layer and a biomass-rich sublayer. This sublayer is expected to be the microbiologically active site for cellulose production and spatial optimization of yeast–AAB metabolic interactions. The pellicles then grow in thickness while expanding their layered organization. A comparison with pellicles grown from pure AAB cultures shows differences in consistency and structure that highlight the impact of yeasts on the structure and properties of kombucha pellicles.

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The effect of yeast culture on rumen fermentation: Growth of the yeast in the rumen and the requirement for viable yeast cells

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600024971 ◽

1993 ◽

Vol 1993 ◽

pp. 175-175 ◽

Cited By ~ 1

Author(s):

S.M. El Hassan ◽

C.J. Newbold ◽

R.J. Wallace

Keyword(s):

Saccharomyces Cerevisiae ◽

Rumen Fermentation ◽

Bacterial Activity ◽

Yeast Cells ◽

Yeast Culture ◽

Current Experiment ◽

Microbial Protein ◽

Live Yeast

Yeast culture (YC) based on Saccharomyces cerevisiae has been reported to stimulate bacterial activity within the rumen, leading to increases in ruminal fibre digestion and microbial protein flow from the rumen (Wallace and Newbold, 1992). Dawson (1987) suggested that S. cerevisiae might grow in the rumen. Newbold et al (1990) found no evidence for the growth of S. cerevisiae in the rumen of sheep when the numbers of live yeast in the rumen were measured at various times after a diet contain YC had been consumed. The current experiment was designed to investigate further the possibility that S. cerevisiae grows in the rumen and to establish the importance of viable yeast cells in the action of YC in the rumen.

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A Loss-of-Function Mutation in the PAS Kinase Rim15p Is Related to Defective Quiescence Entry and High Fermentation Rates of Saccharomyces cerevisiae Sake Yeast Strains

Applied and Environmental Microbiology ◽

10.1128/aem.00165-12 ◽

2012 ◽

Vol 78 (11) ◽

pp. 4008-4016 ◽

Cited By ~ 54

Author(s):

Daisuke Watanabe ◽

Yuya Araki ◽

Yan Zhou ◽

Naoki Maeya ◽

Takeshi Akao ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Frameshift Mutation ◽

Laboratory Strain ◽

Underlying Mechanism ◽

Yeast Cells ◽

Quiescent State ◽

Loss Of Function ◽

Content Type ◽

Yeast Strains ◽

Pas Kinase

ABSTRACTSake yeast cells have defective entry into the quiescent state, allowing them to sustain high fermentation rates. To reveal the underlying mechanism, we investigated the PAS kinase Rim15p, which orchestrates initiation of the quiescence program inSaccharomyces cerevisiae. We found that Rim15p is truncated at the carboxyl terminus in modern sake yeast strains as a result of a frameshift mutation. Introduction of this mutation or deletion of the full-lengthRIM15gene in a laboratory strain led to a defective stress response, decreased synthesis of the storage carbohydrates trehalose and glycogen, and impaired G1arrest, which together closely resemble the characteristic phenotypes of sake yeast. Notably, expression of a functionalRIM15gene in a modern sake strain suppressed all of these phenotypes, demonstrating that dysfunction of Rim15p prevents sake yeast cells from entering quiescence. Moreover, loss of Rim15p or its downstream targets Igo1p and Igo2p remarkably improved the fermentation rate in a laboratory strain. This finding verified that Rim15p-mediated entry into quiescence plays pivotal roles in the inhibition of ethanol fermentation. Taken together, our results suggest that the loss-of-function mutation in theRIM15gene may be the key genetic determinant of the increased ethanol production rates in modern sake yeast strains.

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Multicopy Suppression Screening of Saccharomyces cerevisiae Identifies the Ubiquitination Machinery as a Main Target for Improving Growth at Low Temperatures

Applied and Environmental Microbiology ◽

10.1128/aem.00404-11 ◽

2011 ◽

Vol 77 (21) ◽

pp. 7517-7525 ◽

Cited By ~ 11

Author(s):

Maria José Hernández-López ◽

Sara García-Marqués ◽

Francisca Randez-Gil ◽

Jose Antonio Prieto

Keyword(s):

Saccharomyces Cerevisiae ◽

Surface Protein ◽

State Level ◽

Membrane Properties ◽

Cold Sensitivity ◽

Amino Acid Permease ◽

Gene Encoding ◽

Content Type ◽

Major Interest ◽

Multicopy Suppressors

ABSTRACTA decrease in ambient temperature alters membrane functionality and impairs the proper interaction between the cell and its external milieu. Understanding how cells adapt membrane properties and modulate the activity of membrane-associated proteins is therefore of major interest from both the basic and the applied points of view. Here, we have isolated multicopy suppressors of the cold sensitivity phenotype of atrp1strain ofSaccharomyces cerevisiae. Three poorly characterized genes, namely,ALY2encoding the endocytic adaptor,CAJ1encoding the J protein, andUBP13encoding the ubiquitin C-terminal hydrolase, were identified as mediating increased growth at 12°C of both Trp−and Trp+yeast strains. This effect was likely due to the downregulation of cold-instigated degradation of nutrient permeases, since it was missing from cells of thersp5Δ mutant strain, which contains a point mutation in the gene encoding ubiquitin ligase. Indeed, we found that 12°C treatments reduced the level of several membrane transporters, including Tat1p and Tat2p, two yeast tryptophan transporters, and Gap1, the general amino acid permease. We also found that the lack of Rsp5p increased the steady state level of Tat1p and Tat2p and thatALY2-engineered cells grown at 12°C had higher Tat2p and Gap1p abundance. Nevertheless, the high copy number ofALY2orUBP13improved cold growth even in the absence of Tat2p. Consistent with this,ALY2- andUBP13-engineered cells of the industrial QA23 strain grew faster and produced more CO2at 12°C than did the parental when maltose was used as the sole carbon source. Hence, the multicopy suppressors isolated in this work appear to contribute to the correct control of the cell surface protein repertoire and their engineering might have potential biotechnological applications.

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