Effects Of Trehalose On Ethanol Tolerance And Fermentation In Saccharomyces Cerevisiae1912

Along with the diminishing of fossil fuel reserve, as a kind of clean and renewable energy,alcohol comes to be a hot research topic in the world.The cost cramped the scalization development of alcohol fermentation.High performance strain was the key of alcohol production.Compared with previous strains, Saccharomyces cerevisiae1912which is a industrialized high performance strain showed higher final alcohol concentration, glucose conversion rate, alcohol and hyperosmotic condition tolerance.But the problem is that it comes with a slow growth rate and alcohol fermentation speed as contrasted with current strain.In order to improve the growth and fermentation speed of S.cerevisiae1912.Protein methylation was introduced into fermentation as an exogenous approach of trehalose metabolism regulation.First, on the basis of its original fermenting performance, by means of optimizing the fermentation condition, the suitable conditions of stains fermentation were fixed:37℃, pH5.0, ventilation volume250ml, nitrogen source is ammonium sulfate.Secondly, trehalose cycle as an important for stress response during the cellular response to adverse conditions.The study was undertaken to correlate post-translational protein modification by methylation with the functionality of enzymes involved in trehalose metabolism in adverse conditions.The data presented here strongly suggested that trehalose in S.cerevisiae1912was accumulated extensively in response to ethanol stress, but alcohol was decreased. When the trehalose anabolism were up-regulated and the catabolism were inhibited by methylation, the most dramatic shift in metabolites after this was the accumulation of trehalose.In the meantime the intracellular level of intermediate product trehalose-6-phosphate was decreased due to trehalose-6-phosphate phosphatase was induced.The inhibition of hexokinase which could play a crucial role in the control of the glycolytic flux and neighboring pathways activity was reduced.For this reason, alcohol yield was enhanced slinghtly,and the cell growth speed was increased than it incubate at28℃.