Method for creating distiller's yeast ethanol high yield bacterial strain

Abstract

The invention discloses a method for constructing the ethanol high-yield strains of Saccharomyces cerevisiae, which comprises the following steps: (1) ethylmethane sulfonate is utilized to carry out random mutagenesis to the amphiploid strains of the Saccharomyces cerevisiae to cause the final concentration of the volume of the ethylmethane sulfonate in the bacteria liquid to be processed to be 2 to 4 percent and the concentration of the amphiploid strains of the Saccharomyces cerevisiae to be 2 multiplied by 10<6> to 6 multiplied by 10<6> cell / ml; (2) 3 to 5 rounds of the sexual recombination of high efficient sporulation, spore purification and full integration cause genome recombination between strains in a library to construct the ethanol high-yield strains of the Saccharomyces cerevisiae. The ethanol output of the recombinant strains constructed by the method of the invention is increased by 8.88 percent compared with that of contrast strains, residual sugar is reduced by 64.37 percent, the fermentation cycle is shortened by 10 hours and ethanol and high osmotic resistance are 5.10 times of that of the contrast strains, thus providing excellent strains for the industrial production of fuel ethanol.

Description

technical field [0001] The invention relates to a whole genome transformation method, in particular to a method for constructing a high-yield ethanol-producing strain of Saccharomyces cerevisiae. Background technique [0002] High-concentration ethanol is the main factor for the slow or even termination of yeast ethanol fermentation in the late stage of fermentation and the high residual sugar at the end of fermentation. Screening yeast strains resistant to high-concentration ethanol is one of the important strategies to improve the ethanol fermentation performance of Saccharomyces cerevisiae. Meanwhile, most fermentation-related traits of yeast are controlled by polygenes, which are poorly understood and widely distributed throughout the genome. At present, although genome rearrangement technology has been successfully applied to prokaryotes, the complexity of eukaryotes prevents genome rearrangement technology from being applied to yeast research. For example, yeast has a...

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Problems solved by technology

At present, although genome rearrangement technology has been successfully applied to prokaryotes, the complexity of eukaryotes prevents genome rearrangement technology from being applied to yeast research.

For example, yeast has a thicker cell wall (100-200nm), and the fusion of yeast is a complex process controlled by the MAT allele, etc. These factors make it impossible to directly apply the method of protoplast fusion in yeast

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