Project description:Saccharomyces cerevisiae is bradytroph for class B vitamins, it means that yeast cells exhibit slower growth in the absence of an external source of these metabolites. Alleviating these nutritional requirements for optimal growth performance would represent a valuable phenotypic characteristic for industrial strains since this would result in cheaper processes that would also be less susceptible to contaminations. In the present study, suboptimal growth of S. cerevisiae in absence of either pantothenic acid, para-aminobenzoic acid (pABA), pyridoxine, inositol and biotin were corrected by single or double gene overexpression of native FMS1, ABZ1/ABZ2, SNZ1/SNO1, INO1 and the Cyberlindnera fabianii BIO1, respectively. Several strategies were attempted to improve growth of S. cerevisiae CEN.PK113-7D in absence of thiamine, revealing that overexpression of THI4 and THI4/THI5 was able to improve growth up to 83% of the maximum specific growth rate of the reference CEN.PK113-7D in medium including all vitamins. Although the initial aim of this study was to combine all identified mutations in a single strain, the engineered strain IMX2210 only harboured genes to correct biotin, pABA, pantothenate and inositol bradotrophies. Firstly, this strain was fast-growing at a maximum specific growth rate of 0.28 ± 0.01 h-1 in medium devoid of all vitamins. Secondly, this strain exhibited physiological variables in aerobic glucose limited chemostat cultures at a dilution rate of 0.1 h-1 in absence of vitamins similar to that of the reference strain CEN.PK113-7D grown in the same conditions but in a fully supplemented complete medium. These physiological similarities were further emphasized by the limited differences observed in comparative transcriptome analysis from the chemostat culture grown cells that were essentially affecting genes of the class B vitamins biosynthetic pathways. This work paves the way towards construction of the first fast growing vitamin-independent S. cerevisiae strain.
Project description:Resistance to agricultural fungicides in the field has created a need for discovering fungicides with new modes of action. DNA microarrays, because they provide information on expression of many genes simultaneously, could help to identify the modes of action. To begin an expression pattern database for agricultural fungicides, transcriptional patterns of Saccharomyces cerevisiae strain S288C genes were analysed following 2-h treatments with I50 concentrations of ergosterol biosynthesis inhibitors commonly used against plant pathogenic fungi. Eight fungicides, representing three classes of ergosterol biosynthesis inhibitors, were tested. To compare gene expression in response to a fungicide with a completely different mode of action, a putative methionine biosynthesis inhibitor (MBI) was also tested. Expression patterns of ergosterol biosynthetic genes supported the roles of Class I and Class II inhibitors in affecting ergosterol biosynthesis, confirmed that the putative MBI did not affect ergosterol biosynthesis, and strongly suggested that in yeast, the Class III inhibitor did not affect ergosterol biosynthesis. The MBI affected transcription of three genes involved in methionine metabolism, whereas there were essentially no effects of ergosterol synthesis inhibitors on methionine metabolism genes. There were no consistent patterns in other up- or downregulated genes between fungicides. These results suggest that inspection of gene response patterns within a given pathway may serve as a useful first step in identifying possible modes of action of fungicides. agricultural sterol biosynthesis inhibitor fungicides. Keywords = agriculture Keywords = ergosterol Keywords = methionine Keywords = fungicide Keywords = Saccharomyces cerevisiae S288C Keywords = biosynthesis
Project description:Resistance to agricultural fungicides in the field has created a need for discovering fungicides with new modes of action. DNA microarrays, because they provide information on expression of many genes simultaneously, could help to identify the modes of action. To begin an expression pattern database for agricultural fungicides, transcriptional patterns of Saccharomyces cerevisiae strain S288C genes were analysed following 2-h treatments with I50 concentrations of ergosterol biosynthesis inhibitors commonly used against plant pathogenic fungi. Eight fungicides, representing three classes of ergosterol biosynthesis inhibitors, were tested. To compare gene expression in response to a fungicide with a completely different mode of action, a putative methionine biosynthesis inhibitor (MBI) was also tested. Expression patterns of ergosterol biosynthetic genes supported the roles of Class I and Class II inhibitors in affecting ergosterol biosynthesis, confirmed that the putative MBI did not affect ergosterol biosynthesis, and strongly suggested that in yeast, the Class III inhibitor did not affect ergosterol biosynthesis. The MBI affected transcription of three genes involved in methionine metabolism, whereas there were essentially no effects of ergosterol synthesis inhibitors on methionine metabolism genes. There were no consistent patterns in other up- or downregulated genes between fungicides. These results suggest that inspection of gene response patterns within a given pathway may serve as a useful first step in identifying possible modes of action of fungicides. agricultural sterol biosynthesis inhibitor fungicides. Keywords = agriculture Keywords = ergosterol Keywords = methionine Keywords = fungicide Keywords = Saccharomyces cerevisiae S288C Keywords = biosynthesis
Project description:A propolis-resistant Saccharomyces cerevisiae mutant strain was obtained using an evolutionary engineering strategy based on successive batch cultivation under gradually increasing propolis levels. The mutant strain FD 11 was selected at a propolis concentration that the reference strain could not grow at all. Whole-genome transcriptomic analysis of FD11 was performed with respect to its reference strain to determine differences in gene expression levels between the two strains. Saccharomyces cerevisiae
Project description:Vitamin D deficiency poses a major global health challenge, shaped by environmental and genetic determinants. In this genetic context, the recently discovered rs11542462 nonsense variant in the short-chain dehydrogenase/reductase 42E1 (SDR42E1) gene emerges as a critical regulator, though its biological implications remain largely unexplored. Our comprehensive bioinformatic assessments revealed pronounced expression of SDR42E1 in skin keratinocytes and the analogous HaCat human keratinocyte cell lines, prompting us to select the latter as an experimental model. Employing CRISPR/Cas9 technology and an integrated multi-omics approach, combining transcriptomics and proteomics, we explored SDR42E1's functions, focusing on its localization, role in lipid and steroid biosynthesis, and the consequent effects on vitamin D biosynthesis. We highlighted the significant cytoplasmic presence of the SDR42E1 protein, essential for lipid and steroid production. Our whole transcriptomics analysis of the SDR42E1 depleted model showed a notable disruption in the steroid biosynthesis pathway by 1.6-fold (P = 0.03). This disruption was accompanied by considerable alterations in genes involved in vitamin D synthesis, a finding supported by our proteomics data. Notably, SERPINB2 (P = 2.17E−103), EBP (P = 2.46E−13), and DHCR7 (P = 8.03E−09) showed significant elevations by ~2-3 fold, while ALPP (P < 2.2E−308), SLC7A5 (P = 1.96E−215), and CYP26A1 (P = 1.06E−08) decreased by ~1.5-3 fold. These alterations led to an accumulation of 7-dehydrocholesterol, preventing its conversion to vitamin D3, as evidenced by our drug enrichment analysis (P = 4.39E−06). This investigation unveils SDR42E1's pivotal role in vitamin D homeostasis and its broader impact on metabolic pathways. Our findings provide a foundation for future research and highlight the potential of precision medicine in addressing vitamin D deficiency, offering significant insights into the genetic regulation of vitamin D biosynthesis.
Project description:Nickel-resistant Saccharomyces cerevisiae mutant was obtained by evolutionary engineering. The reference strain which was used to select this nickel-resistant mutant could not grow even at 0.5 mM NiCl2 whereas this mutant was shown to be resistant upto 5.3 mM NiCl2 concentration. Whole-genome microarray analysis might be promising to identify the nickel resistance mechanisms in the yeast cells. The reference Saccharomyces cerevisiae strain and the nickel-resistant mutant were grown in minimal medium to an Optical Density (OD600) of 1.00 which correspond to the logarithmic growth phase of the yeast cells. Cultures were harvested and whole RNA isolation was carried out. The experiment was repeated three times.
Project description:Evolutionary engineering strategy was used for selection of ethanol-tolerant Saccharomyces cerevisiae clones under gradually increasing ethanol stress levels. Clones B2 and B8 were selected based on their higher ethanol-tolerance and higher ethanol production levels. Whole genome microarray analysis was used for identifying the gene expression levels of these two evolved clones compared to the reference strain.
Project description:A caffeine-resistant Saccharomyces cerevisiae mutant strain was obtained using an evolutionary engineering strategy based on successive batch cultivation at gradually increasing caffeine levels. The mutant strain Caf905-2 was selected at a caffeine concentration where its reference strain could not grow at all. Whole-genome transcriptomic analysis of Caf905-2 was performed with respect to its reference strain.