Analysis of the effect of TSA2 gene overexpression on acetic acid tolerance of Saccharomyces cerevisiae

Abstract

In order to protect the environment and maintain the sustainable development of ecology, the second-generation fuel ethanol has been widely developed and utilized. The raw material of the second generation of fuel ethanol is lignocellulose, but lignocellulose cannot be directly decomposed by microorganisms, and it needs to be pre-treated to make it fermentable monosaccharides before it can be used in the microbial fermentation process. During the pretreatment process, in addition to fermentable monosaccharides, many small molecule compounds are released, which can inhibit the growth and metabolism of microorganisms. Acetic acid is one of the most abundant small molecule compounds, and studies have found that excessive acetic acid can adversely affect the metabolism, signaling and cell growth of Saccharomyces cerevisiae, and even inhibit the production of ethanol. In order to improve the acetic acid tolerance of the ethanol fermentation strain, a histone point mutant with significantly improved xylose utilization and ethanol yield was obtained. In order to further explore the regulatory mechanism, transcriptome sequencing was performed on this strain. Through analysis, it was found that the expression level of TSA2 gene was significantly increased in this mutant. In order to verify the effect of TSA2 gene on acetic acid tolerance of yeast, we carried out experiments related to this subject. The overexpression of TSA2 gene in xylose-utilizing strains and the detection of acetic acid tolerance showed that the overexpression of TSA2 gene could significantly improve the acetic acid tolerance of the strains. The experiment provided an effective element for the development of second-generation ethanol fermentation strains with high acetic acid tolerance.