Improvement of inhibitor tolerance in Saccharomyces cerevisiae by overexpression of the quinone oxidoreductase family gene YCR102C

ABSTRACT Budding yeast Saccharomyces cerevisiae is widely used for lignocellulosic biorefinery. However, its fermentation efficiency is challenged by various inhibitors (e.g. weak acids, furfural) in the lignocellulosic hydrolysate, and acetic acid is commonly present as a major inhibitor. The effects of oxidoreductases on the inhibitor tolerance of S. cerevisiae have mainly focused on furfural and vanillin, whereas the influence of quinone oxidoreductase on acetic acid tolerance is still unknown. In this study, we show that overexpression of a quinone oxidoreductase-encoding gene, YCR102C, in S. cerevisiae, significantly enhanced ethanol production under acetic acid stress as well as in the inhibitor mixture, and also improved resistance to simultaneous stress of 40°C and 3.6 g/L acetic acid. Increased catalase activities, NADH/NAD+ ratio and contents of several metals, especially potassium, were observed by YCR102C overexpression under acetic acid stress. To our knowledge, this is the first report that the quinone oxidoreductase family protein is related to acid stress tolerance. Our study provides a novel strategy to increase lignocellulosic biorefinery efficiency using yeast cell factory.

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INHIBITION OF THE GROWTH OF TOLERANT YEAST Saccharomyces cerevisiae STRAIN I136 BY A MIXTURE OF SYNTHETIC INHIBITORS

Indonesian Journal of Agricultural Science ◽

10.21082/ijas.v18n1.2017.p17-24 ◽

2017 ◽

Vol 18 (1) ◽

pp. 17

Author(s):

Eny Ida Riyanti ◽

Edy Listanto

Keyword(s):

Saccharomyces Cerevisiae ◽

Acetic Acid ◽

Carbon Sources ◽

Resistance Mechanism ◽

Lag Phase ◽

Cell Factory ◽

Yeast Saccharomyces Cerevisiae ◽

Fermentation Products ◽

Hydroxymethyl Furfural ◽

Cell Biomass

<p>Biomass from lignocellulosic wastes is a potential source for biobased products. However, one of the constraints in utilization of biomass hydrolysate is the presence of inhibitors. Therefore, the use of inhibitor-tolerant microorganisms in the fermentation is required. The study aimed to investigate the effect of a mixture of inhibitors on the growth of Saccharomyces cerevisiae strain I136 grown in medium containing synthetic inhibitors (acetic acid, formic acid, furfural, 5-hydroxymethyl furfural/5-HMF, and levulinic acid) in four different concentrations with a mixture of carbon sources, glucose (50 g.l-1) and xylose (50 g.l-1) at 30oC. The parameters related to growth and fermentation products were observed. Results showed that the strain was able to grow in media containing natural inhibitors (BSL medium) with µmax of 0.020/h. Higher level of synthetic inhibitors prolonged the lag phase, decreased the cell biomass and ethanol production, and specific growth rate. The strain could detoxify furfural and 5-HMF and produced the highest ethanol (Y(p/s) of 0.32 g.g-1) when grown in BSL. Glucose was utilized as its level decreased in a result of increase in cell biomass, in contrast to xylose which was not consumed. The highest cell biomass was produced in YNB with Y (x/s) value of 0.25 g.g-1. The strain produced acetic acid as a dominant side product and could convert furfural into a less toxic compound, hydroxyl furfural. This robust tolerant strain provides basic information on resistance mechanism and would be useful for bio-based cell factory using lignocellulosic materials. </p>

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Polygenic analysis of very high acetic acid tolerance in the yeast Saccharomyces cerevisiae reveals a complex genetic background and several new causative alleles

Biotechnology for Biofuels ◽

10.1186/s13068-020-01761-5 ◽

2020 ◽

Vol 13 (1) ◽

Author(s):

Marija Stojiljkovic ◽

María R. Foulquié-Moreno ◽

Johan M. Thevelein

Keyword(s):

Saccharomyces Cerevisiae ◽

Acetic Acid ◽

Genetic Background ◽

Acid Tolerance ◽

Acetic Acid Tolerance ◽

Yeast Saccharomyces Cerevisiae ◽

Polygenic Analysis ◽

Very High

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Polygenic analysis and targeted improvement of the complex trait of high acetic acid tolerance in the yeast Saccharomyces cerevisiae

Biotechnology for Biofuels ◽

10.1186/s13068-015-0421-x ◽

2016 ◽

Vol 9 (1) ◽

Cited By ~ 51

Author(s):

Jean-Paul Meijnen ◽

Paola Randazzo ◽

María R. Foulquié-Moreno ◽

Joost van den Brink ◽

Paul Vandecruys ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Acetic Acid ◽

Acid Tolerance ◽

Complex Trait ◽

Acetic Acid Tolerance ◽

Yeast Saccharomyces Cerevisiae ◽

Polygenic Analysis

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Enhancement of Acetic Acid Tolerance in Saccharomyces cerevisiae by Overexpression of theHAA1Gene, Encoding a Transcriptional Activator

Applied and Environmental Microbiology ◽

10.1128/aem.02356-12 ◽

2012 ◽

Vol 78 (22) ◽

pp. 8161-8163 ◽

Cited By ~ 72

Author(s):

Koichi Tanaka ◽

Yukari Ishii ◽

Jun Ogawa ◽

Jun Shima

Keyword(s):

Saccharomyces Cerevisiae ◽

Acetic Acid ◽

Acid Stress ◽

Acid Tolerance ◽

Transcriptional Activator ◽

Wild Type ◽

Acetic Acid Tolerance ◽

Content Type ◽

In The Wild ◽

Overexpressing Strain

ABSTRACTHaa1 is a transcriptional activator required forSaccharomyces cerevisiaeadaptation to weak acids. Here we show that the constitutiveHAA1-overexpressing strain acquired a higher level of acetic acid tolerance. Under conditions of acetic acid stress, the intracellular level of acetic acid was significantly lower inHAA1-overexpressing cells than in the wild-type cells.

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Eukaryotic translation factor eIF5A contributes to acetic acid tolerance in Saccharomyces cerevisiae via transcriptional factor Ume6p

Biotechnology for Biofuels ◽

10.1186/s13068-021-01885-2 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Yanfei Cheng ◽

Hui Zhu ◽

Zhengda Du ◽

Xuena Guo ◽

Chenyao Zhou ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Acetic Acid ◽

Adaptive Response ◽

Acid Tolerance ◽

Peptide Bond ◽

Transcriptional Factor ◽

Yeast Cells ◽

Acetic Acid Tolerance ◽

Translation Factor ◽

Industrial Strains

Abstract Background Saccharomyces cerevisiae is well-known as an ideal model system for basic research and important industrial microorganism for biotechnological applications. Acetic acid is an important growth inhibitor that has deleterious effects on both the growth and fermentation performance of yeast cells. Comprehensive understanding of the mechanisms underlying S. cerevisiae adaptive response to acetic acid is always a focus and indispensable for development of robust industrial strains. eIF5A is a specific translation factor that is especially required for the formation of peptide bond between certain residues including proline regarded as poor substrates for slow peptide bond formation. Decrease of eIF5A activity resulted in temperature-sensitive phenotype of yeast, while up-regulation of eIF5A protected transgenic Arabidopsis against high temperature, oxidative or osmotic stress. However, the exact roles and functional mechanisms of eIF5A in stress response are as yet largely unknown. Results In this research, we compared cell growth between the eIF5A overexpressing and the control S. cerevisiae strains under various stressed conditions. Improvement of acetic acid tolerance by enhanced eIF5A activity was observed all in spot assay, growth profiles and survival assay. eIF5A prompts the synthesis of Ume6p, a pleiotropic transcriptional factor containing polyproline motifs, mainly in a translational related way. As a consequence, BEM4, BUD21 and IME4, the direct targets of Ume6p, were up-regulated in eIF5A overexpressing strain, especially under acetic acid stress. Overexpression of UME6 results in similar profiles of cell growth and target genes transcription to eIF5A overexpression, confirming the role of Ume6p and its association between eIF5A and acetic acid tolerance. Conclusion Translation factor eIF5A protects yeast cells against acetic acid challenge by the eIF5A-Ume6p-Bud21p/Ime4p/Bem4p axles, which provides new insights into the molecular mechanisms underlying the adaptive response and tolerance to acetic acid in S. cerevisiae and novel targets for construction of robust industrial strains.

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Sphingolipid biosynthesis upregulation by TOR complex 2–Ypk1 signaling during yeast adaptive response to acetic acid stress

Biochemical Journal ◽

10.1042/bcj20160565 ◽

2016 ◽

Vol 473 (23) ◽

pp. 4311-4325 ◽

Cited By ~ 27

Author(s):

Joana F. Guerreiro ◽

Alexander Muir ◽

Subramaniam Ramachandran ◽

Jeremy Thorner ◽

Isabel Sá-Correia

Keyword(s):

Acetic Acid ◽

Protein Kinase ◽

Cellular Response ◽

Molecular Mechanisms ◽

Acid Stress ◽

Acid Tolerance ◽

Industrial Biotechnology ◽

Acetic Acid Tolerance ◽

Spoilage Yeasts ◽

Sphingolipid Biosynthesis

Acetic acid-induced inhibition of yeast growth and metabolism limits the productivity of industrial fermentation processes, especially when lignocellulosic hydrolysates are used as feedstock in industrial biotechnology. Tolerance to acetic acid of food spoilage yeasts is also a problem in the preservation of acidic foods and beverages. Thus understanding the molecular mechanisms underlying adaptation and tolerance to acetic acid stress is increasingly important in industrial biotechnology and the food industry. Prior genetic screens for Saccharomyces cerevisiae mutants with increased sensitivity to acetic acid identified loss-of-function mutations in the YPK1 gene, which encodes a protein kinase activated by the target of rapamycin (TOR) complex 2 (TORC2). We show in the present study by several independent criteria that TORC2–Ypk1 signaling is stimulated in response to acetic acid stress. Moreover, we demonstrate that TORC2-mediated Ypk1 phosphorylation and activation is necessary for acetic acid tolerance, and occurs independently of Hrk1, a protein kinase previously implicated in the cellular response to acetic acid. In addition, we show that TORC2–Ypk1-mediated activation of l-serine:palmitoyl-CoA acyltransferase, the enzyme complex that catalyzes the first committed step of sphingolipid biosynthesis, is required for acetic acid tolerance. Furthermore, analysis of the sphingolipid pathway using inhibitors and mutants indicates that it is production of certain complex sphingolipids that contributes to conferring acetic acid tolerance. Consistent with that conclusion, promoting sphingolipid synthesis by adding exogenous long-chain base precursor phytosphingosine to the growth medium enhanced acetic acid tolerance. Thus appropriate modulation of the TORC2–Ypk1–sphingolipid axis in industrial yeast strains may have utility in improving fermentations of acetic acid-containing feedstocks.

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