Industrial Saccharomyces cerevisiae bacterial strain by using CRISPR/Cas9 system for knocking out XKS1 gene and construction method

Abstract

The invention discloses an industrial Saccharomyces cerevisiae bacterial strain with XKS1 gene knockout for high efficient production of xylitol, the bacterial strain is named SEB9, and a preservationnumber is CGMCC No.14272; the invention also relates to a construction method of the Saccharomyces cerevisiae bacterial strain, and the method comprises the following steps: a KanMX gene of an initial strain is knocked out in order to construct a KanMX-bacterial strain, and a KanMX-bacterial strain with high xylitol yield is screened; the XKS1 gene of the screened KanMX-bacterial strain is knocked out in order to construct a delta XKS1 bacterial strain, and a delta XKS1 bacterial strain with high xylitol yield is screened. A CRISPR / Cas9 gene editing technology is used, the XKS1 gene can be rapidly and fast knocked out by one-time yeast conversion, in order to block further metabolism from xylosone into D-xylulose 5-phosphate, and obtain the bacterial strain with high-yield of xylitol; compared with the initial strain, the Saccharomyces cerevisiae bacterial strain SEB9 prepared by the construction method has superior performance for producing xylitol by fermentation of xylose, the yield may reach a theoretical value 1.0, yield and production of xylitol are effectively improved, and the strain has good application prospects.

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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