Saccharomyces cerevisiae bottom of the fermentor vs. feeding and fermentation
Ontology highlight
ABSTRACT: This SuperSeries is composed of the following subset Series: GSE26617: Saccharomyces cerevisiae bottom of the fermentor vs. feeding GSE26618: Saccharomyces cerevisiae bottom of the fermentor vs. fermentation Refer to individual Series
Project description:The main objective was to identify genes regulated during different stages of fermentation: bottom of the fermentor, feeding and the fermentation stage. The experiment was further validated by microbiological assays. The control refers to the bottom of the fermentor. For analysis, fermentation was compared to the control for two strains: CAT and PE-2.
Project description:The main objective was to identify genes regulated during different stages of fermentation: bottom of the fermentor, feeding and the fermentation stage. The experiment was further validated by microbiological assays. The control refers to the bottom of the fermentor. For analysis, feeding was compared to the control for two strains: CAT and PE-2.
Project description:High concenHigh concentration acetic acid in the fermentation medium represses cell growth, metabolism and fermentation efficiency of Saccharomyces cerevisiae, which is widely used for cellulosic ethanol production. Our previous study proved that supplementation of zinc sulfate in the fermentation medium improved cell growth and ethanol fermentation performance of S. cerevisiae under acetic acid stress condition. However, the molecular mechanisms is still unclear. To explore the underlying mechanism of zinc sulfate protection against acetic acid stress, transcriptomic and proteomic analysis were performed. The changed genes and proteins are related to carbon metabolism, amino acid biosynthesis, energy metabolism, vitamin biosynthesis and stress responses. In a total, 28 genes showed same expression in transcriptomic and proteomic data, indicating that zinc sulfate affects gene expression at posttranscriptional and posttranslational levels.tration acetic acid in the fermentation medium represses cell growth, metabolism and fermentation efficiency of Saccharomyces cerevisiae, which is widely used for cellulosic ethanol production. Our previous study proved that supplementation of zinc sulfate in the fermentation medium improved cell growth and ethanol fermentation performance of S. cerevisiae under acetic acid stress condition. However, the molecular mechanisms is still unclear. To explore the underlying mechanism of zinc sulfate protection against acetic acid stress, transcriptomic and proteomic analysis were performed. The changed genes and proteins are related to carbon metabolism, amino acid biosynthesis, energy metabolism, vitamin biosynthesis and stress responses. In a total, 28 genes showed same expression in transcriptomic and proteomic data, indicating that zinc sulfate affects gene expression at posttranscriptional and posttranslational levels.
Project description:The main objective was to identify genes regulated during different stages of fermentation: bottom of the fermentor, feeding and the fermentation stage. The experiment was further validated by microbiological assays.
Project description:The main objective was to identify genes regulated during different stages of fermentation: bottom of the fermentor, feeding and the fermentation stage. The experiment was further validated by microbiological assays.
Project description:Bacteria in the genus Streptomyces are soil dwelling oligotrophs and important producers of secondary metabolites. Previously we showed that global mRNA expression was subject to a series of metabolic and regulatory switches during the life time of a fermentor batch culture of S. coelicolor M145. Here we analyse the proteome from eight time points from the same fermentor culture and, as phosphate availability is an important regulator of secondary metabolite production, compare this to the proteome of a similar time course from an S. coelicolor mutant, INB201 (M-NM-^TphoP), defective in the control of phosphate utilisation. The proteomes provide a detailed view of enzymes involved in central carbon and nitrogen metabolism. Trends in protein expression over the time courses were deduced from a protein abundance index which also revealed the importance of stress pathway proteins in both cultures. As expected the M-NM-^TphoP mutant was deficient in expression of PhoP-dependent genes and several putatively compensatory metabolic and regulatory pathways for phosphate scavenging were detected. Notably there is a succession of switches that co-ordinately induce the production of enzymes for five different secondary metabolite biosynthesis pathways over the course of the batch cultures and these were not confined to the stationary phase. 36 samples, no replicates; one hour resolution from 23-36h and 41-48h; half hour resolution from 36-41h; two hour resolution 48-60h; sample missing for 34 h
Project description:The industrially important fungus Aspergillus niger feeds naturally on decomposing plant material, for which it is equipped with a range of enzyme systems. A significant proportion of plant material are lipids that might be available either as for energy storage or as membrane building blocks. With 63 potential lipase-encoding genes in its genome, A. niger has the tools to degrade these extracellular lipids. In contrast to polysaccharide-degrading enzyme networks not much is known about the signalling and regulatory processes that control lipase expression and activity in fungi both under laboratory and natural occurring conditions. A pulse of 1 mM of various oils was applied to four bioreactor-grown A. niger cultures to examine (i) whether A. niger responds at the level of gene transcription, (ii) at what time point this effect is detected most accurately, and (iii) whether differences between the response towards oils are observed. The triglyceride olive oil induces genes encoding peroxins and enzymes of fatty acid metabolism. A complex oil mixture extracted from wheat gluten, which is enriched for digalactosyl-diglycerides, induces genes encoding peroxins as well as enzymes of fatty acid metabolism, but with different expression profile when compared to olive oil. Pure digalactosyldiglyceride, a proxy for plant membrane lipids, does not trigger a transcriptional response. Keywords: time course; induction experiment In one week, 4 fermentor cultures were run in 2.2-liter batch fermentors in which A. niger was grown on 100 mM sorbitol. At 14 hours after oxygen supply had switched from headspace to sparger-inlet each fermentor was induced with 22 mL medium which contained 100 mM (final concentration in fermentor: 1 mM) of either olive oil, a complex oil mixture extracted from wheat gluten, pure wheat digalactosyldiglycerides, or was induced with a solution of minimal medium containing only 0.2% (in fermentor, final concentration 0.002%) triton X-100 which served as emulsifier agent. For each fermentor vessel, a sample of 10 mL was taken prior to induction (T=0), or 30 minutes, 1 hour, or 2 hours after induction. Every sample was hybridized onto a single microarray, yielding in total 16 DNA microarrays.
Project description:A transcriptome analysis of the bottom-fermenting yeast S. pastorianus KBY011 during a time course of lager beer fermentation in the wort was carried out (0, 2, 6, 8, 10, 14, 24, 34, 40, 52, 64, 120, and 156h). RNA preparation followed by DNA microarray analysis was performed for the yeast harvested from the yeast storage tank either just prior to, or just after the actual fermentation, as well as from 12 different time points during fermentation.
Project description:Biofilms with immobilized cells in industrial fermentation are beneficial. Encased in extracellular polymeric substance, cells forming biofilms are regulated by various factors. Nitric oxide (NO), as a signaling molecule, recognized as quorum sensing molecule regulating microbe biofilm formation. Regulation mechanisms of NO on bacteria biofilm have been studied extensively and deeply, while on fungus are rarely studied. In this study, we observed that low concentration of NO enhanced S. cerevisiae biofilm formation. Transcriptional and proteomic analysis revealed that transcription factor MAC1 was activated in biofilm cells under NO treatment. Overexpressed MAC1 increased yeast biofilm formation bypassing regulating the expression level of FLO11. Increased copper and iron contents in NO treated and MAC1 overexpressed cells were not responsible for increased biofilm formation. Among six downstream genes of MAC1, overexpressed CTR1 contributed yeast biofilm formation. Moreover, MAC1 and CTR1 contributed to biofilm cells ethanol resistance resulting from enhanced biofilm. The role of CTR1 protein in yeast biofilm formation may result from its hydrophobic residues in N-terminal extracellular domain. These findings suggested a NO-mediated biofilm formation mechanism that NO regulated expression levels of CTR1 through activating its transcription factor MAC1, leading enhanced biofilm formation.
Project description:The yeast Dekkera bruxellensis is as ethanol tolerant as Saccharomyces cerevisiae and may be found in bottled wine. It causes the spoilage of wine, beer, cider and soft drinks. In wines, the metabolic products responsible for spoilage by Dekkera bruxellensis are mainly volatile phenols. These chemical compounds are responsible for the taints described as M-bM-^@M-^XM-bM-^@M-^XmedicinalM-bM-^@M-^YM-bM-^@M-^Y in white wines (due to vinyl phenols) and as M-bM-^@M-^XM-bM-^@M-^XleatherM-bM-^@M-^YM-bM-^@M-^Y, M-bM-^@M-^XM-bM-^@M-^Xhorse sweatM-bM-^@M-^YM-bM-^@M-^Y and M-bM-^@M-^XM-bM-^@M-^XstableM-bM-^@M-^YM-bM-^@M-^Y in red wines (due to ethyl phenols mainly 4-ethylphenol). Apart from the negative aroma nuances imparted by these yeasts, positive aromas such as M-bM-^@M-^XsmokyM-bM-^@M-^Y, M-bM-^@M-^XspicyM-bM-^@M-^Y and M-bM-^@M-^XtoffeeM-bM-^@M-^Y are also cited. Our goal was to identify the impact that the wine spoilage yeast Dekkera bruxellensis has on fermenting S. cerevisiae cells, especially on its gene expression level. To this end we co-inoculated both yeast species at the start of fermentation in a synthetic wine must, using S. cerevisiae-only fermentations without Dekkera bruxellensis as a control. All fermentations were employed in special membrane reactors (50 KDa pore size cut-off) physically separating Dekkera bruxellensis from wine yeast S. cerevisiae. Biomass separation with this membrane was done to abolish the possibility of hybridizing also D. bruxellensis probes on Agilent V2 (8x15K format) G4813 DNA microarrays designed just for S. cerevisiae ORF targets. The 50 KDa pore membrane separating both yeasts allowed the exchange of ethanol, metabolites and sugars during the fermentation. Fermentations were carried out in synthetic wine must in duplicate for both the control S. cerevisiae (strain Lalvin EC1118) and mixed fermentation. Sampling of yeast S. cerevisiae for RNA extractions were performed at 22 h of fermentation, during the exponential growth phase of S. cerevisiae, at 92 h and 144 h of fermentation, during its early and late stationary growth phase and at 187 h of fermentation, during its phase of growth decline.