Guo Zhong-peng, Zhang Liang, Ding Zhong-yang, Wang Zheng-Xiang, Shi Gui-Yang
The Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, People's Republic of China.
Appl Microbiol Biotechnol. 2009 Feb;82(2):287-92. doi: 10.1007/s00253-008-1777-7. Epub 2008 Nov 19.
The two homologous genes GPD1 and GPD2, encoding two isoenzymes of NAD(+)-dependent glycerol-3-phosphate dehydrogenase in industrial yeast Saccharomyces cerevisiae CICIMY0086, had been deleted. The obtained two kinds of mutants gpd1Delta and gpd2Delta were studied under alcoholic fermentation conditions. gpd1Delta mutants exhibited a 4.29% (relative to the amount of substrate consumed) decrease in glycerol production and 6.83% (relative to the amount of substrate consumed) increased ethanol yield while gpd2Delta mutants exhibited a 7.95% (relative to the amount of substrate consumed) decrease in glycerol production and 7.41% (relative to the amount of substrate consumed) increased ethanol yield compared with the parental strain. The growth rate of the two mutants were slightly lower than that of the wild type under the exponential phase whereas ANG1 (gpd1Delta) and the decrease in glycerol production was not accompanied by any decline in the protein content of the strain ANG1 (gpd1Delta) but a slight decrease in the strain ANG2 (gpd2Delta). Meanwhile, dramatic decrease of acetate acid formation was observed in strain ANG1 (gpd1Delta) and ANG2 (gpd2Delta) compared to the parental strain. Therefore, it is possible to improve the ethanol yield by interruption of glycerol pathway in industrial alcoholic yeast.
工业酿酒酵母CICIMY0086中编码两种NAD(+)依赖性甘油-3-磷酸脱氢酶同工酶的两个同源基因GPD1和GPD2已被敲除。对获得的两种突变体gpd1Δ和gpd2Δ在酒精发酵条件下进行了研究。与亲本菌株相比，gpd1Δ突变体的甘油产量降低了4.29%（相对于消耗的底物量），乙醇产量提高了6.83%（相对于消耗的底物量）；而gpd2Δ突变体的甘油产量降低了7.95%（相对于消耗的底物量），乙醇产量提高了7.41%（相对于消耗的底物量）。在指数生长期，这两种突变体的生长速率略低于野生型，而ANG1（gpd1Δ）甘油产量的降低并未伴随着ANG1（gpd1Δ）菌株蛋白质含量的任何下降，但ANG2（gpd2Δ）菌株有轻微下降。同时，与亲本菌株相比，在ANG1（gpd1Δ）和ANG2（gpd2Δ）菌株中观察到乙酸形成显著减少。因此，通过中断工业酒精酵母中的甘油途径有可能提高乙醇产量。
