Regulation Of Lactobacillus Plantarum On Oxidative Metabolism Of Saccharomyces Cerevisiae During Fermentation

Many studies have shown that Lactobacillus plantarum can inhibit the growth of Saccharomyces cerevisiae cells and decrease the yield of ethanol during fermentation.When L.plantarum was cocultivated with S.cerevisiae on the condition of the same amount of oxygen exposure,the utilization of glucose by yeast cells is declined and thus further leads to the decrease of ATP synthesis.However,there are few studies to explain that the decrease in ATP whether can cause an increase in reactive oxygen species(ROS)content,which in turn affects the oxidative metabolism of yeast cells.Based on the above idea,the effect of L.plantarum on yeast ROS content was evaluated.The results showed that the ROS content in the co-culture group was decreased.Simultaneously,the contents of mitochondrial membrane potential,MDA and ATP were determined.The results showed that L.plantarum did not cause oxidative damage to yeast.Next,the expression levels of key genes involved in ROS production,clearance,regulation,and energy utilization were used to analyze by qRT-PCR.The results indicated that oxidative tolerance of yeast cells in the experimental group was improved.Besides,under the stimulation of different concentrations of H2O2,especially at 0.5 mM,L.plantarum increased the survival rate of yeast cells.Finally,the effect of quorum sensing on ROS content of yeast cells was determined.The results showed that deletion of ARO80 increased ROS content of yeast,which indicate that quorum sensing molecules could regulate ROS.Taken together,it is helpful for us to understand the regulation of L.plantarum on the oxidative metabolism of yeast,and to further understand the relationship of the bacterial and fungal so as to provide theoretical support for the rational control of bacterial infection and improve fermentation efficiency.