Effect of Nitrosative Stress on Biofilm Formation and Upregulation of 2,3-Butanediol Dehydrogenase in Saccharomyces Cerevisiae
摘要
Nitrosative stress is a phenomenon where reactive nitrogen species (RNS), oxidizes different cellular macromolecules. In this study we investigated the effect of sub-toxic dose of different nitrosative stress agents on S. cerevisiae grown with 2% ethanol as sole carbon source. Our SEM analysis showed significant increase in biofilm production under stress with changes in cellular morphology. Genes responsible for biofilm formation like FLO11, BSC2 and MAC1 in S. cerevisiae upon treatment with ac. NaNO2 and SNP were also found to be upregulated. Redox enzymes like glutathione reductase (GR) showed an increase in specific activity in treated sets but catalase activity had no significant difference. Utilization of ethanol as sole carbon source was followed primarily by assessing the specific activity of Adh2p, which showed a significant 4-fold increase in both treated sets. This was also corroborated with gene expression analysis of ADH2. Together with this estimation of important enzymes of other associated metabolic pathways were also done to understand the changes in metabolic flux. Importantly both glyoxylate cycle and TCA cycle were found to be partially blocked under stress condition whereas, aldehyde reductase (Bdh2p) an important enzyme for 2,3-Butanediol production was found to have upregulated significantly. Altogether our study provides the first report on the effect of nitrosative stress on S. cerevisiae grown on ethanol as a carbon source with possibility to produce 2,3-Butanediol, an industrially important compound, that has a huge demand in the paint, drug and cosmetic industries.