Analysis of the effect of Histone H3K36Q point mutation on acetic acid resistance of yeast

Abstract

In the rapid development of material economy in modern life, our demand for new energy is also increasing. As the preferred raw material for the preparation of fuel ethanol, lignocellulose provides a good idea to solve the current social problems such as resource exhaustion, environmental pollution and greenhouse effect. Saccharomyces cerevisiae has the characteristics of high sugar, high ethanol tolerance, clear genetic background and high ethanol yield, making it the first choice in lignocellulosic ethanol fermentation strain. The complex chemical structure of lignocellulose prevents it from being directly used by microorganisms. Instead, it needs to be pretreated and hydrolyzed to produce monosaccharides before it can be used in fermentation production. However, after pretreatment and hydrolysis of lignocellulose, in addition to fermentable monosaccharides, a variety of small molecular compounds can be produced to inhibit the growth and metabolism of microorganisms. Acetic acid is one of the most typical small molecule inhibitors, which is highly contained in lignocellulosic hydrolysate. It can directly cross the cell membrane through passive transport, affect the physiological and biochemical reactions of cells, and inhibit cell growth. Histone modification mainly occurs in lysine and serine residues of histones. Common histone modification types include methylation, acetylation, ubiquitination, and cassinization, etc., which can directly or indirectly affect physiological and biochemical processes such as gene expression, DNA replication, DNA repair, etc. In this experiment, we first constructed a mutant strain of histone H3K36, mutated lysine (H3K36) at the 36th position of histone H3 into glutamine, and glutamine residues could simulate the acetylation of histones, so as to detect the influence of H3K36 simulated acetylation on acetic acid tolerance of Saccharomyces cerevisiae. The final results showed that the growth of H3K36Q strain was consistent with that of the wild strain without significant differences, and its acetic acid resistance was not significantly improved compared with that of the wild strain. These results indicated that H3K36 simulated acetylation did not affect acetic acid tolerance of Saccharomyces cerevisiae. The object of the work is H3K36-mutant Saccharomyces cerevisiae. The subject of the work is influence of H3K36 simulated acetylation on acetic acid tolerance of Saccharomyces cerevisiae. The aim of the work is to study influence of H3K36 simulated acetylation on acetic acid tolerance of Saccharomyces cerevisiae. The tasks of the work are to construct a mutant strain of histone H3K36 and to detect the influence of H3K36 simulated acetylation on acetic acid tolerance of Saccharomyces cerevisiae.