Metschnikowia pulcherrima Influences the Expression of Genes Involved in PDH Bypass and Glyceropyruvic Fermentation in Saccharomyces cerevisiae

ABSTRACTFungi can use a wide variety of nitrogen sources. In the absence of preferred sources such as ammonium, glutamate, and glutamine, secondary sources, including most other amino acids, are used. Expression of the nitrogen utilization pathways is very strongly controlled at the transcriptional level. Here, we investigated the regulation of nitrogen utilization in the pathogenic yeastCandida parapsilosis. We found that the functions of many regulators are conserved with respect toSaccharomyces cerevisiaeand other fungi. For example, the core GATA activatorsGAT1andGLN3have a conserved role innitrogencataboliterepression (NCR). There is one ortholog ofGZF3andDAL80, which represses expression of genes in preferred nitrogen sources. The regulatorsPUT3andUGA3are required for metabolism of proline and γ-aminobutyric acid (GABA), respectively. However, the role of the Dal81 transcription factor is distinctly different. InS. cerevisiae, Dal81 is a positive regulator of acquisition of nitrogen from GABA, allantoin, urea, and leucine, and it is required for maximal induction of expression of the relevant pathway genes. InC. parapsilosis, induction of GABA genes is independent of Dal81, and deletingDAL81has no effect on acquisition of nitrogen from GABA or allantoin. Instead, Dal81 represses arginine synthesis during growth under preferred nitrogen conditions.IMPORTANCEUtilization of nitrogen by fungi is controlled bynitrogencataboliterepression (NCR). Expression of many genes is switched off during growth on nonpreferred nitrogen sources. Gene expression is regulated through a combination of activation and repression. Nitrogen regulation has been studied best in the model yeastSaccharomyces cerevisiae. We found that although many nitrogen regulators have a conserved function inSaccharomycesspecies, some do not. The Dal81 transcriptional regulator has distinctly different functions inS. cerevisiaeandC. parapsilosis. In the former, it regulates utilization of nitrogen from GABA and allantoin, whereas in the latter, it regulates expression of arginine synthesis genes. Our findings make an important contribution to our understanding of nitrogen regulation in a human-pathogenic fungus.

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Resistance Mechanisms of Saccharomyces cerevisiae to Commercial Formulations of Glyphosate Involve DNA Damage Repair, the Cell Cycle, and the Cell Wall Structure

G3 Genes|Genome|Genetics ◽

10.1534/g3.120.401183 ◽

2020 ◽

Vol 10 (6) ◽

pp. 2043-2056

Author(s):

Apoorva Ravishankar ◽

Amaury Pupo ◽

Jennifer E. G. Gallagher

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Wall ◽

Resistance Mechanisms ◽

Mapk Signaling ◽

Fragile Sites ◽

Cell Wall Structure ◽

Wall Structure ◽

Global Changes ◽

Expression Of Genes ◽

Wide Range

The use of glyphosate-based herbicides is widespread and despite their extensive use, their effects are yet to be deciphered completely. The additives in commercial formulations of glyphosate, though labeled inert when used individually, have adverse effects when used in combination with other additives along with the active ingredient. As a species, Saccharomyces cerevisiae has a wide range of resistance to glyphosate-based herbicides. To investigate the underlying genetic differences between sensitive and resistant strains, global changes in gene expression were measured, when yeast were exposed to a glyphosate-based herbicide (GBH). Expression of genes involved in numerous pathways crucial to the cell’s functioning, such as DNA replication, MAPK signaling, meiosis, and cell wall synthesis changed. Because so many diverse pathways were affected, these strains were then subjected to in-lab-evolutions (ILE) to select mutations that confer increased resistance. Common fragile sites were found to play a role in adaptation to resistance to long-term exposure of GBHs. Copy number increased in approximately 100 genes associated with cell wall proteins, mitochondria, and sterol transport. Taking ILE and transcriptomic data into account it is evident that GBHs affect multiple biological processes in the cell. One such component is the cell wall structure which acts as a protective barrier in alleviating the stress caused by exposure to inert additives in GBHs. Sed1, a GPI-cell wall protein, plays an important role in tolerance of a GBH. Hence, a detailed study of the changes occurring at the genome and transcriptome levels is essential to better understand the effects of an environmental stressor such as a GBH, on the cell as a whole.

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

Biotechnology for Biofuels ◽

10.1186/s13068-020-01822-9 ◽

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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Biochemical and molecular effects of yeast extract applications on anthocyanin accumulation in cv. Sangiovese.

BIO Web of Conferences ◽

10.1051/bioconf/20191303005 ◽

2019 ◽

Vol 13 ◽

pp. 03005

Author(s):

Chiara Pastore ◽

Gianluca Allegro ◽

Gabriele Valentini ◽

Emilia Colucci ◽

Fabrizio Battista ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Phenolic Compounds ◽

Secondary Metabolism ◽

Yeast Extract ◽

Anthocyanin Accumulation ◽

Yeast Saccharomyces Cerevisiae ◽

Potted Plants ◽

Expression Of Genes ◽

Anthocyanin Concentration ◽

Molecular Effects

The effect of biotic and abiotic elicitors on the secondary metabolism in grapevine is gaining a lot of interest, as it has been shown that they can increase the accumulation of phenolic compounds and anthocyanins in particular. The aim of this research was to verify the biochemical and molecular effects of the application of LalVigne™ MATURE (Lallemand, St. Simon, France), 100% inactivated natural yeast (Saccharomyces cerevisiae) on the anthocyanin accumulation in potted plants of Sangiovese. In both years, LVM plants did not differ from C in technological ripening at harvest. A significant increase in anthocyanin concentration and the expression of genes involved in their biosynthesis was found in 2016 in LVM grapes compared to C, while in 2017, a year with extremely warm temperatures, the anthocyanins of C and LVM were comparable, despite a slight increase in LVM after the second treatment.

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EXPLORATORY MODELING OF YEAST STRESS RESPONSE AND ITS REGULATION WITH gCCA AND ASSOCIATIVE CLUSTERING

International Journal of Neural Systems ◽

10.1142/s0129065705000220 ◽

2005 ◽

Vol 15 (04) ◽

pp. 237-246 ◽

Cited By ~ 4

Author(s):

JANNE NIKKILÄ ◽

CHRISTOPHE ROOS ◽

EERIKA SAVIA ◽

SAMUEL KASKI

Keyword(s):

Saccharomyces Cerevisiae ◽

Binding Sites ◽

Contingency Table ◽

Information Sources ◽

New Combination ◽

Yeast Saccharomyces Cerevisiae ◽

Stress Regulation ◽

Canonical Correlations ◽

Expression Of Genes ◽

Combination Of Methods

We model dependencies between m multivariate continuous-valued information sources by a combination of (i) a generalized canonical correlations analysis (gCCA) to reduce dimensionality while preserving dependencies in m - 1 of them, and (ii) summarizing dependencies with the remaining one by associative clustering. This new combination of methods avoids multiway associative clustering which would require a multiway contingency table and hence suffer from curse of dimensionality of the table. The method is applied to summarizing properties of yeast stress by searching for dependencies (commonalities) between expression of genes of baker's yeast Saccharomyces cerevisiae in various stressful treatments, and summarizing stress regulation by finally adding data about transcription factor binding sites.

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Effects of some pesticides on two yeast strains Saccharomyces cerevisiae and Metschnikowia pulcherrima

OENO One ◽

10.20870/oeno-one.2005.39.2.903 ◽

2005 ◽

Vol 39 (2) ◽

pp. 67

Author(s):

Dalal Jawich ◽

Christo Hilan ◽

Rachad Saliba ◽

Roger Lteif ◽

Pierre Strehaiano

Keyword(s):

Saccharomyces Cerevisiae ◽

Reaction Rates ◽

Aerobic Growth ◽

Initial Value ◽

Yeast Strains ◽

Metschnikowia Pulcherrima

The effect of different concentrations (0-20 LMR) of six pesticides on the aerobic growth of two yeast strains (Saccharomyces cerevisiae, Metschnikowia pulcherrima) was analysed. The penconazole was shown as the most efficient and its effect was then studied under fermentative conditions. Saccharomyces cerevisiae appeared very sensitive under aerobiosis while the fermentative cultures seemed poorly affected. On the opposite, Metschnikowia pulcherrima was poorly affected under aerobiosis but was severely affected under fermentative conditions. The yields as well as the reaction rates decreased when initial concentrations of penconazole were increased. At least, it was shown that both strains were able to adsorb a certain ratio of the pesticide; but the pesticide was not degraded. Also for an initial value greater than 2 LMR, the residual quantity of the pesticide was above the admitted level.

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Effects of Low-Shear Modeled Microgravity on Cell Function, Gene Expression, and Phenotype in Saccharomyces cerevisiae

Applied and Environmental Microbiology ◽

10.1128/aem.03050-05 ◽

2006 ◽

Vol 72 (7) ◽

pp. 4569-4575 ◽

Cited By ~ 58

Author(s):

B. Purevdorj-Gage ◽

K. B. Sheehan ◽

L. E. Hyman

Keyword(s):

Gene Expression ◽

Saccharomyces Cerevisiae ◽

Cell Function ◽

Yeast Cells ◽

Lag Phase ◽

Limited Information ◽

Cellular Functions ◽

Modeled Microgravity ◽

Expression Of Genes ◽

Low Shear

ABSTRACT Only limited information is available concerning the effects of low-shear modeled microgravity (LSMMG) on cell function and morphology. We examined the behavior of Saccharomyces cerevisiae grown in a high-aspect-ratio vessel, which simulates the low-shear and microgravity conditions encountered in spaceflight. With the exception of a shortened lag phase (90 min less than controls; P < 0.05), yeast cells grown under LSMMG conditions did not differ in growth rate, size, shape, or viability from the controls but did differ in the establishment of polarity as exhibited by aberrant (random) budding compared to the usual bipolar pattern of controls. The aberrant budding was accompanied by an increased tendency of cells to clump, as indicated by aggregates containing five or more cells. We also found significant changes (greater than or equal to twofold) in the expression of genes associated with the establishment of polarity (BUD5), bipolar budding (RAX1, RAX2, and BUD25), and cell separation (DSE1, DSE2, and EGT2). Thus, low-shear environments may significantly alter yeast gene expression and phenotype as well as evolutionary conserved cellular functions such as polarization. The results provide a paradigm for understanding polarity-dependent cell responses to microgravity ranging from pathogenesis in fungi to the immune response in mammals.

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