甘油代谢对酿酒酵母酒精发酵的影响

Effects of Glycerol Metabolism on Ethanol Fermentation by Industrial Saccharomyces cerevisiae

以工业酒精酵母菌株(Saccharomyces cerevisiae Y)为对象,通过生孢子法获得其a型和α型单倍体。根据同源重组原理构建整合载体pUC19-GPD1::ΩKm线性化后电击转化进入a型单倍体,G418抗性筛选缺失GPD1基因的转化子S.cerevisiae Y(a,△gpd1)。重组菌S.cerevisiae Y(a,△gpd1)与α型单倍体杂交获得二倍体,采用PCR扩增法鉴定得到GPD1全突变菌株S.cerevisiae Y(△gpd1,△gpd1)。分别以20g/L和150g/L的初糖在摇瓶中进行发酵实验考察。结果表明,S.cerevisiae Y(a,△gpd1)的葡萄糖转甘油率分别从12.43%和6.04%降低到9.35%和5.54%,葡萄糖转酒精率分别从36.4.9%和39.96%提高到36.91%和40.29%;而S.cerevisiae Y(△gpd1,△gpd1)的葡萄糖转甘油率分别从14.16%和7.49%降低到10.46%和5.79%,葡萄糖转酒精率分别从36.23%和39.89%提高到38.52%和41.50%。

According to the method of sporulation, the two haploids （a type and a type） of an industrial Saccharomyces cerevisiae Y were achieved. Based on homologous recombination, a recombinant plasmid （pUC 19-GPD1：：ΩKm） was constructed and introduced into haploid （a type） by electroporation after it was linearized. The transformants were screened by G418 resistance.After hybridization between transformant and haploid （or type）, the diploid mutant S.cerevisiae Y（△gpdl,△gpdl） was generated and comfirmed by the method of PCR. By flask shaking test with the initial sugar concentration as 20 g/L or 150 g/L, hoploid GPD 1 △ mutant showed that glycerol production rates decreased from 12.43 % and 6.04 % to 9.35 % and 5.54 %, ethanol production rates increased from 36.49 % and 39.96 % to 36.91% and 40.29 %; diploid GPD1 null mutation showed that glycerol production rates decreased from 14.16 % and 7.49 % to 10.46 % and 5.79 %, and ethanol production rates increased from 36.23 % and 39.89 % to 38.52 % and 41.50 %.