Analysis Of The Key Enzymes Of Central Metabolic Pathway In Brewing Yeast Under Different Carbon Sources

Yeast is one of the most extensively-existed， favored and the safest microbial species，which has played an important role in traditional fermentation industry and modernbiotechnology. In this paper based on the growth of yeast metabolism were greater impactedby the carbon source， design optimization through the medium of preparation， in-depthstudy of different carbon sources on yeast growth and metabolism related impacts， as well asyeast cells during apoptosis yeast metabolism changes in the process.Some key enzymes of metabolism in Saccharomyces cerevisiae FCC2146were studiedin this paper compared with those of Saccharomyces cerevisiae FCC2144. The resultsindicated that pyruvate kinase，glucose-6-phosphate dehydrogenase，ethanol dehydrogenase，malate dehydrogenase and isocitrate dehydrogenase in Saccharomyces cerevisiae FCC2146have higher activity compared with those of Saccharomyces cerevisiae FCC2144. That’s thereason why the osmophilic yeast in the hypertonic environment can maintain the balance ofenergy metabolism and the requirements of growth.The accumulation of alcohol is considered the main factor which affect yeastfermentation capacity， organic acids will also accumulated in the medium in thefermentation process， and acetic acid is the major component in all these accumulatedorganic acids. Yeast can use acetic acid as a carbon source in the absence of sugar. The resultsindicate that the activities of PKY and G6PDH were repressed in acetate cultivation，theactivities of MDH and ICDH were increased in acetate cultivation， the activities of ICL andPEPCK were significantly increased in acetate cultivation compared with glucose cultivation.Many key enzymes of metabolism in Cerevisiae fermentation were influenced by acetatecultivation.To explore the influence of the programmed cell death (PCD) in yeast Saccharomycescerevisiae induced by acetic acid on the activities of key enzymes of metabolism inSaccharomyces cerevisiae, the results indicate that the respiration of cell correlate with theprocess of apoptosis, the activity attenuated rate of ICDH、MDH、G6PDH and PEPCK are significantly higher than that of PKY and ADH. The apoptosis of Saccharomyces cerevisiaehas a good correlation with the mitochondrial decomposition and the inactivation of therelated key enzymes on the respiratory chain.