Method for quickly and efficiently constructing good S yeast strain

Abstract

The invention relates to a method for quickly and efficiently constructing good S yeast strain. On the basis of determining the optimal acting time of EMS (methyl methane sulfonate) on amphiploid cells of S yeast (namely, Saccharomycesrouxii used in soya sauce enterprises), S yeast amphiploid of non-conventional yeast strains is subjected to random mutagenesis by using EMS to generate an S yeast genetic diversity strain library, and genome rearrangement is generated among the strains in the library through multiple sexual recombination of efficient spore generation, spore purification, full integration and salt-resistant screening so as to construct S yeast recombinant strain with good fermentation performance. The salt resistance of the recombinant strain constructed by the method is obviously improved, the fermentation period is shortened by 10 days, the generated flavor substances are obviously improved compared with wild strains, and an important flavor substance 4-EG is also generated; and the good strain can generate thick and ester-flavor soya sauce flavor in high salt liquid state fermentation, has better physicochemical standard, and is provided for the industrial production of soya sauce.

Description

technical field [0001] The invention belongs to the field of biotechnology and food fermentation, and relates to a genetic operation method for strain transformation, in particular to a method for rapidly and efficiently constructing an excellent strain of S yeast. Background technique [0002] High-concentration salt is the main factor determining the metabolic activity of yeast during brine fermentation in the later stage of soy sauce fermentation. Therefore, screening high-salt-tolerant S yeast strains is one of the important strategies to improve the flavor and quality of soy sauce. At the same time, most of the flavor-related characteristics of S. yeast are controlled by polygenes, which are widely distributed throughout the genome, and people know little about them. Therefore, the method of genome-wide transformation, that is, the genome rearrangement strategy, is generally used. The method of genetically modifying S yeast solves the problem. At present, although geno...

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Problems solved by technology

At present, although genome rearrangement technology has been successfully applied to prokaryotes and a small number of eukaryotes, the complexity of eukaryotes limits the wide application of genome rearrangement technology.

For example, the cell wall of S yeast is thicker than that of the model organism Saccharomyces cerevisiae, and the fusion of S yeast is controlled by the MAT allele. Low

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