An industrial Saccharomyces cerevisiae strain and construction method for knocking out the xks1 gene by using the CRISPR/Cas9 system

Abstract

The invention discloses an industrial Saccharomyces cerevisiae strain that knocks out the XKS1 gene to efficiently produce xylitol, which is named SEB9 and has a preservation number of CGMCC No. 14272; the invention also relates to a construction method of the above-mentioned Saccharomyces cerevisiae strain, which Including the following steps: Knock out the KanMX gene of the starting strain to construct KanMX — strains, and screen for high xylitol production of KanMX — strains; knockout selected KanMX — ΔXKS1 strain was constructed by the XKS1 gene of the strain, and the ΔXKS1 strain with high xylitol yield was screened. The invention uses the CRISPR / Cas9 gene editing technology to quickly and quickly knock out the XKS1 gene through one-time yeast transformation, and blocks the further metabolism of xylulose to 5-phosphate xylulose to obtain a high-yield xylitol strain; Compared with the starting strain, the Saccharomyces cerevisiae strain SEB9 prepared by the construction method of the invention has superior performance in xylose fermentation to produce xylitol, and the yield can be close to the theoretical value of 1.0, which can effectively improve the yield of xylitol and xylose Alcohol production, which has a good application prospect.

Description

technical field [0001] The invention relates to the technical field of microbial genetic engineering, in particular to an industrial Saccharomyces cerevisiae strain and a construction method for efficiently producing xylitol by using a CRISPR / Cas9 system to knock out the XKS1 gene. Background technique [0002] Agricultural wastes such as straws, husks, and cores are the most abundant renewable organic substances on the earth. About 900 million tons of straws are produced in China every year. However, due to the high cost of processing these agricultural wastes, although they have attracted widespread attention, However, most of the transformation and treatment methods are discarded or directly burned in the field, which causes a great waste of resources and environmental pollution, and also destroys the ecological balance. And xylitol can be obtained by reducing the hydrolyzate of hemicellulose (mainly xylose). Xylitol is one of the most promising biological platform compo...

AI Technical Summary

Problems solved by technology

These endogenous metabolic pathways lead to xylitol consumption, making the xylitol yield lower than the theoretical yield of 1.0

[0006] The industrial Saccharomyces cerevisiae expression system is relatively complicated. The currently used Candida tropicalis CtXYL1 (encoding xylose reductase) gene is heterologously expressed in Saccharomyces cerevisiae. There is still the problem that the yield of xylitol is low and cannot meet the needs of fermentation

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