Saccharomyces Cerevisiae
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Fermentation ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 33
Yanfeng Liu ◽  
Bing Wan ◽  
Fan Yang ◽  
Xiaolong Zhang ◽  
Jianghua Li ◽  

Saccharomyces cerevisiae and Lactobacillus panis are ethanol and lactic acid producers in Maotai-flavor Baijiu fermentation. Understanding their interaction is important to regulate the microbiome composition during fermentation and biosynthesis of ethanol and lactic acid. This study is the first to analyze the interaction between S. cerevisiae and L. panis at different growth phases during co-cultivation. Results showed that the different growth phases of S. cerevisiae modulated L. panis growth. Metabolomics analysis showed that amino acids and nucleoside secreted by S. cerevisiae promote L. panis growth, while ethanol inhibited L. panis growth. Furthermore, S. cerevisiae modulated L. panis cell growth under varying sugar concentrations. Simulated solid-state fermentation demonstrated that regulating the sugar concentration or the ratio of S. cerevisiae to L. panis could inhibit L. panis cell growth and reduce lactic acid accumulation. This study provided an understanding on Maotai-flavor Baijiu microbiome, which might be useful for metabolite regulation.

Antioxidants ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 161
Nikolaos Nenadis ◽  
Efi Samara ◽  
Fani Th. Mantzouridou

In the present work, the role of the carboxyl group of o-dihydroxybenzoic acids (pyrocatechuic, 2,3-diOH-BA and protocatechuic, 3,4-diOH-BA) on the protection against induced oxidative stress in Saccharomyces cerevisiae was examined. Catechol (3,4-diOH-B) was included for comparison. Cell survival, antioxidant enzyme activities, and TBARS level were used to evaluate the efficiency upon the stress induced by H2O2 or cumene hydroperoxide. Theoretical calculation of atomic charge values, dipole moment, and a set of indices relevant to the redox properties of the compounds was also carried out in the liquid phase (water). Irrespective of the oxidant used, 2,3-diOH-BA required by far the lowest concentration (3–5 μM) to facilitate cell survival. The two acids did not activate catalase but reduced superoxide dismutase activity (3,4-diOH-BA>2,3-diOH-BA). TBARS assay showed an antioxidant effect only when H2O2 was used; equal activity for the two acids and inferior to that of 3,4-diOH B. Overall, theoretical and experimental findings suggest that the 2,3-diOH-BA high activity should be governed by metal chelation. In the case of 3,4-diOH BA, radical scavenging increases, and chelation capacity decreases. The lack of carboxyl moiety (3,4-diOH B) adds to radical scavenging, interaction with lipophilic free radicals, and antioxidant enzymes. The present study adds to our knowledge of the antioxidant mechanism of dietary phenols in biological systems.

2022 ◽  
Vol 10 (1) ◽  
pp. 173
Manuel Ramírez ◽  
Alberto Martínez ◽  
Felipe Molina

The yeasts Torulaspora delbrueckii (Td) and Saccharomyces cerevisiae (Sc) may show a killer phenotype that is encoded in dsRNA M viruses (V-M), which require the helper activity of another dsRNA virus (V-LA or V-LBC) for replication. Recently, two TdV-LBCbarr genomes, which share sequence identity with ScV-LBC counterparts, were characterized by high-throughput sequencing (HTS). They also share some similar characteristics with Sc-LA viruses. This may explain why TdV-LBCbarr has helper capability to maintain M viruses, whereas ScV-LBC does not. We here analyze two stretches with low sequence identity (LIS I and LIS II) that were found in TdV-LBCbarr Gag-Pol proteins when comparing with the homologous regions of ScV-LBC. These stretches may result from successive nucleotide insertions or deletions (indels) that allow compensatory frameshift events required to maintain specific functions of the RNA-polymerase, while modifying other functions such as the ability to bind V-M (+)RNA for packaging. The presence of an additional frameshifting site in LIS I may ensure the synthesis of a certain amount of RNA-polymerase until the new compensatory indel appears. Additional 5′- and 3′-extra sequences were found beyond V-LBC canonical genomes. Most extra sequences showed high identity to some stretches of the canonical genomes and can form stem-loop structures. Further, the 3′-extra sequence of two ScV-LBC genomes contains rRNA stretches. The origin and possible functions of these extra sequences are here discussed.

2022 ◽  
Olga L. Meshcheryakova ◽  
Galina P. Shuvaeva ◽  
Tatyana V. Sviridova ◽  
Anna A. Tolkacheva ◽  
Olga S. Korneeva

The researchers of this study investigated the biosynthesis of squalene by the yeast S. cerevisiae VGSH-2 through the activity of squalene epoxidase, which is a key enzyme in the conversion of squalene to ergosterol. It has been established that under aerobic conditions the antimycotic drug terbinafine promotes the switching of ergosterol formation to squalene synthesis. This switch occurs through specific inhibition of the squalene epoxidase of the yeast S. cerevisiae VGSH-2, thus increasing the biosynthetic ability of the yeast towards squalene. According to the results of this study, the optimal concentration of terbinofine in the nutrient medium was 0.3 μmol / cm3 . This concentration led to a 5-fold decrease in squalene epoxidase activity and a 7-8 times increase in squalene synthesis. The results obtained can be used to develop a competitive technology for the industrial production of squalene by microbial synthesis. Keywords: squalene, yeast, biosynthesis, inhibition of activity, terbinafine, squalene epoxidase, Saccharomices cerevisiae VGSH-2

Metabolites ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 74
David Lao-Martil ◽  
Koen J. A. Verhagen ◽  
Joep P. J. Schmitz ◽  
Bas Teusink ◽  
S. Aljoscha Wahl ◽  

Central carbon metabolism comprises the metabolic pathways in the cell that process nutrients into energy, building blocks and byproducts. To unravel the regulation of this network upon glucose perturbation, several metabolic models have been developed for the microorganism Saccharomyces cerevisiae. These dynamic representations have focused on glycolysis and answered multiple research questions, but no commonly applicable model has been presented. This review systematically evaluates the literature to describe the current advances, limitations, and opportunities. Different kinetic models have unraveled key kinetic glycolytic mechanisms. Nevertheless, some uncertainties regarding model topology and parameter values still limit the application to specific cases. Progressive improvements in experimental measurement technologies as well as advances in computational tools create new opportunities to further extend the model scale. Notably, models need to be made more complex to consider the multiple layers of glycolytic regulation and external physiological variables regulating the bioprocess, opening new possibilities for extrapolation and validation. Finally, the onset of new data representative of individual cells will cause these models to evolve from depicting an average cell in an industrial fermenter, to characterizing the heterogeneity of the population, opening new and unseen possibilities for industrial fermentation improvement.

2022 ◽  
Yu Zhang ◽  
Mengyan Li ◽  
Hanying Wang ◽  
Juqing Deng ◽  
Jianxing Liu ◽  

Abstract The mechanism of fungal cell wall synthesis and assembly is still unclear. Saccharomyces cerevisiae (S. cerevisiae) and pathogenic fungi are conserved in cell wall construction and response to stress signals, and often respond to cell wall stress through activated cell wall integrity (CWI) pathways. Whether the YLR358C open reading frame regulates CWI remains unclear. This study found that the growth of S. cerevisiae with YLR358C knockout was significantly inhibited on the medium containing different concentrations of cell wall interfering agents Calcofluor White (CFW), Congo Red (CR) and sodium dodecyl sulfate (SDS). CFW staining showed that the cell wall chitin was down-regulated, and transmission electron microscopy also observed a decrease in cell wall thickness. Transcriptome sequencing and analysis showed that YLR358C gene may be involved in the regulation of CWI signaling pathway. It was found by qRT-PCR that WSC3, SWI4 and HSP12 were differentially expressed after YLR358C was knocked out. The above results suggest that YLR358C may regulate the integrity of the yeast cell walls and has some potential for application in fermentation.

2022 ◽  
Shravan Raghu ◽  
Myron Smith ◽  
Andrew Simons

Abstract Environmental unpredictability results in the evolution of bet-hedging traits, which maximize long-term fitness but are, by definition, suboptimal over short time scales. However, because suboptimal traits are expected to be purged by selection in the shorter term, the persistence of bet hedging remains perplexing. Here, we test the hypothesis that bet hedging persists through the evolution of constraint on short-term adaptation. We experimentally evolve Saccharomyces cerevisiae across two sequential treatments in which the frequency of extreme heat shocks decreases. We predict that experimental evolution under lower frequency heat shocks will result in greater adaptive constraint, or “purge-resistant” bet hedging. Constraint is assayed as evolutionary persistence of heat shock tolerance (HST) under constant benign conditions. As predicted, we find the retention of HST only in lines evolved under reduced frequency detrimental conditions. Results help explain the evolution of bet hedging, and challenge the traditional view that evolutionary constraint is inherently maladaptive.

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