Breeding of Saccharomyces cerevisiae with Cross-tolerance and Its Application to Production of Ethanol from Sugarcane Juice
In this study,Saccharomyces cerevisiae AS2.1189 was used as the parent strain,a strain library containing 561 mutants was established by nitrous acid mutagenesis.Through the initial screening method of tolerance plate seeding,genetically stable mutants with stable genetic performance were screened after five generations of cultivation.Among them,Y75,Y226,and Y324 strains were mutants with improved heat resistance,osmotic pressure resistance,and alcohol resistance.The growth rate and final cell concentration of the three mutants were higher than those of the parent strains under extreme tolerance conditions.The mutant Y75 was studied to use cane juice to ferment alcohol under stress conditions.The results showed that the highest cell concentration of Y75 was about 2.5 OD600 units higher than that of the parent strain;the pH of the fermentation broth of Y75 was about 0.4 units lower than that of the parent strain;and the sugar consumption rate of Y75 was significantly higher than that of the parent strain,but the final residual sugar concentration is basically the same;after 20 hours of fermentation,the alcohol yield of Y75 is about 1%higher than that of the parent strain,and the final alcohol yield of Y75 and the parent strain are 14.82%and 14.22%,respectively.
万方数据
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