Wang Han, Zhang Liang, Shi Guiyang
Sheng Wu Gong Cheng Xue Bao. 2014 Sep;30(9):1381-9.
Glycerol is the main byproduct in ethanol production by Saccharomyces cerevisiae. In order to improve ethanol yield and the substrate conversion, a cassette about 4.5 kb for gene homologous recombination, gpd2Δ::PGK1(PT)-POS5-HyBR, was constructed and transformed into the haploid strain S. cerevisiae S1 (MATa) to replace the GPD2 gene by POS5 gene. The NADH kinase gene POS5 was successfully over expressed in the recombinant strain S. cerevisiae S3. Comparing with the parent strain, the recombinant strain S. cerevisiae S3 exhibited an 8% increase in ethanol production and a 33.64% decrease in glycerol production in the conical flask fermentation with an initiatory glucose concentration of 150 g/L. Overexpression of NADH kinase gene seems effective in reducing glycerol production and increasing ethanol yield.
甘油是酿酒酵母生产乙醇过程中的主要副产物。为了提高乙醇产量和底物转化率，构建了一个约4.5 kb的用于基因同源重组的盒式结构gpd2Δ::PGK1(PT)-POS5-HyBR，并将其转化到单倍体酿酒酵母菌株S1（MATa）中，用POS5基因替换GPD2基因。NADH激酶基因POS5在重组菌株酿酒酵母S3中成功过表达。与亲本菌株相比，在初始葡萄糖浓度为150 g/L的锥形瓶发酵中，重组菌株酿酒酵母S3的乙醇产量提高了8%，甘油产量降低了33.64%。NADH激酶基因的过表达似乎在降低甘油产量和提高乙醇产量方面是有效的。
