Effects of Glycerol Metabolism on Ethanol Fermentation by Industrial Saccharomyces cerevisiae

According to the method of sporulation, the two haploids (a type and α type) of an industrial Saccharomyces cerevisiae Y were achieved. Based on homologous recombination, a recombinant plasmid (pUC19-GPD1::Ω Km) 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 (α type), the diploid mutant S.cerevisiae Y(△gpd1,△gpd1) 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 GPD1△ 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 %.