Regulation Of Saccharomyces Cerevisiae Oxidative Tolerance Based On RCK1-mediated Quorum Sensing

Saccharomyces cerevisiae is a model-engineered strain widely used in fermentation production,but its fermentation efficiency is regulated by many factors,one of which is oxidative stress.Therefore,improving the oxidation tolerance of strains is of great value for industrial production.Quorum sensing is an important mode of communication between S.cerevisiae cells,which may play a regulatory role in cellular oxidative tolerance.This paper mainly elaborates the correlation between quorum sensing and oxidative tolerance,explores its regulatory mechanism under the mediation of RCK1,a gene related to the MAPK pathway.Moreover,the gene RCK1 overexpression was controlled in segments to enhance strains tolerance and fermentation efficiency.The results of the study are as follows:1.The gene RCK1 was overexpressed by homologous recombination method in wild-type S.cerevisiae S288 c and S.cerevisiae △ARO80 with the population-sensing gene ARO80 knocked out,and intracellular ROS content and oxidative stress tolerance were evaluated.The results showed that the ROS content of △ARO80 increased and the stress tolerance was weakened.The ROS content of the overexpressed strains S288c-RCK1 and △ARO80-RCK1 decreased,and the stress tolerance was enhanced.The expression of genes related to oxidative metabolism of four strains was measured,and it was found that △ ARO80 strain inhibited glutathione expression,slowed down ROS clearance rate,and led to ROS content accumulation.S288c-RCK1 and △ARO80-RCK1 activated SOD enzyme expression,enhanced ROS clearance level,and alleviated ROS accumulation to a certain extent.2.In order to enhance the fermentation performance,improve the antioxidant capacity in the middle and late stages of fermentation,and artificially controlled segmented overexpression of RCK1 S.cerevisiae S288c’-RCK1 was constructed.The relative expression of RCK1 with different induction durations was evaluated,and the intracellular ROS content and oxidative tolerance before and after induction were explored.The results showed that the induction time was 2 h,and the expression degree of RCK1 was the strongest.After induction,the intracellular ROS content of S288c’-RCK1 was significantly reduced,and the oxidative tolerance was significantly enhanced.3.Through genome-wide transcriptomic analysis,the overall difference between S288 c and S288c’-RCK1 was explored.GO and KEGG databases were used for functional annotation classification and selection of 15 genes for RT-qPCR validation.Results A total of 207 differential genes were screened,mainly related to cell metabolic processes,ribosomes and catalase.