Effects of site-directed mutagenesis of HOG1 gene on xylose metabolism and acetic acid tolerance in Saccharomyces cerevisiae

Abstract

In the future fuel ethanol development process, lignocellulosic is an important raw material，the use of lignocellulosic ethanol production ethanol can not only reduce environmental pollution. In addition, a variety of substances that inhibit the growth and fermentation of Saccharomyces cerevisiae were produced during the pretreatment of lignocellulosic raw materials，among which acetic acid was the main inhibitor component, and yeast was more sensitive to acetic acid during xylose fermentation than under glucose conditions. Therefore, improving the xylose metabolism capacity and acetic acid stress tolerance of Saccharomyces cerevisiae strains is the key to selecting and breeding efficient fermentation strains. The object of the work is mutant strains of S. cerevisiae with HOG1 gene. The subject of the work is the effect of HOG1 gene on xylose utilization and acetic acid tolerance of mutant S. cerevisiae. This study aimed to investigate the effect of HOG1 gene on xylose utilization and acetic acid tolerance. The HOG1 gene was site-mutated by fusion PCR to convert the 144th aspartic acid of HGO1 protein into alanine, and the HOG1 mutant strains of Saccharomyces cerevisiae were constructed, and their growth and fermentation in the medium containing xylose-acetic acid were compared. The tasks of the work to construct mutant strains of S. cerevisiae with HOG1 gene, study their growth and fermentation in the xylose-acetic acid medium. The results showed that the point mutations of HOG1 gene had a significant effect on xylose utilization and acetic acid tolerance. This study provides a new metabolic engineering strategy and theoretical basis for improving the efficiency and economy of lignocellulosic biotransformation, and also provides a new perspective and method for revealing the molecular mechanism of stress response in S. cerevisiae.