Study Of Pulsed Electric Field Enhances The Fermentation Capacity Of Saccharomyces Cerevisiae And Related Mechanisms

In recent years,with the increase of social demand and the development of science and technology,the application of Saccharomyces cerevisiae in industrial production is no longer limited to the traditional wine brewing and other fields,using the fermentation of Saccharomyces cerevisiae to produce bio-ethanol,glycerol and various high value-added compounds recently show huge market potential and economic value.In order to meet the growing production needs,it is necessary to increase the fermentation capacity of Saccharomyces cerevisiae to shorten the fermentation time and increase the conversion rate of related metabolites.Therefore,the use of various ancillary techniques to improve fermentation efficiency or to improve the fermentation process has attracted the attention of academics and industry.Pulsed electric field(PEF)has been used as a sterilization method in food safety since its development.With the deepening of research,people have a more detailed understanding of the electroporation" characteristics of pulsed electric fields.This technology has been gradually applied to the auxiliary extraction,molecular or drug delivery of cell contents.In recent years,studies on increasing the activity of enzyme-activated microorganisms by pulsed electric fields have also been reported.Related studies have found that pulsed electric fields under appropriate conditions do not cause microbial damage or death,but can increase the activity of enzymes and stimulate the synthesis of intracellular metabolites.Therefore,pulsed electric field technology has begun to attract researchers' attention in the field of improving microbial activity.At the same time,because of its own advantages of high efficiency,low energy consumption,pollution-free and so on,it shows its application advantages.However,reports on the effects of PEF on the fermentation capacity of Saccharomyces cerevisiae,especially the production of metabolites such as ethanol,are rare.The glucose fermentation and growth kinetics of Saccharomyces cerevisiae under the action of pulsed electric field are still unclear.In order to further deepen the application field and potential of pulsed electric field,and provide a new strategy and method for Saccharomyces cerevisiae fermentation industry.This work explored the effect of pulsed electric field on the fermentation ability of Saccharomyces cerevisiae.On the basis of PEF improving the fermentation capacity of Saccharomyces cerevisiae,the expression of related genes and proteins in yeast cells was analyzed which is for understanding the mechanism of PEF-induced fermentation of Saccharomyces cerevisiae.It provides experimental basis and theoretical support for the practical application of pulsed electric field technology in fermentation industry.The main contents and results of this research are as follows:1.The change of fermentation ability of Saccharomyces cerevisiae under pulsed electric field with appropriate conditions was explored.By detecting and analyzing the changes in the content of residual sugar,alcohol and glycerol in the fermentation substrate,it was confirmed that the appropriate pulse electric field effect improved the fermentation ability of Saccharomyces cerevisiae.In addition,yeast cells also exhibited higher growth rates under prolonged dynamic PEF stimulation.2.Mainly aimed at the genes related to the glycolytic pathway of Saccharomyces cerevisiae.The transcription level changes of related genes were analyzed by RT-qPCR.The results showed that the pulsed electric field under appropriate conditions induced higher glycolysis flux in yeast cells.And the transcription level of ethanol synthesis-related genes increased more significantly.3.Mass spectrometry was used to analyze the changes of protein expression of Saccharomyces cerevisiae before and after PEF from the level of proteomics.Through the analysis of the results of mass spectrometry identification,it was found that the effect of PEF with appropriate strength on Saccharomyces cerevisiae cells mainly focused on the cell functions and behaviors such as transport,fermentation and metabolite synthesis of carbohydrates.