斯达氏油脂酵母利用混合糖发酵产油脂

Microbial production of lipids by cofermentation of Glucose and xylose with Lipomyces starkeyi 2#

研究了斯达氏油脂酵母Lipomyces starkeyi2#利用葡萄糖-木糖混合糖为碳源生长和油脂积累特性。L.star-keyi2#利用70 g/L葡萄糖和70 g/L木糖作为碳源在30℃下摇瓶发酵96 h,糖利用率均达90%以上,菌体生物量分别为14.1 g/L和13.1 g/L,油脂质量分数分别为55.7%和52.6%。相同条件下该菌株利用混合糖(葡萄糖46 g/L,木糖24 g/L)为碳源时总糖利用率、生物量和油脂质量分数分别为75.1%,15.0 g/L和40.0%。借助于P lackett-Burm an设计法和单因子实验法对培养条件进行了优化,结果表明发酵96 h混合糖利用率可达到97.3%,发酵120 h后混合糖利用率、生物量和菌体油脂质量分数分别达99.5%、19.0 g/L和52.6%。生物量得率和油脂得率分别达到27%和14%。

Microbial production of lipids by cofermentation of glucose and xylose with oleaginous yeast Lipomyces starkeyi 2# was examined. When cultivated by shaking flask at 30 ℃ with glucose （70 g/L） or xylose （70 g/L） as sole carbon source for 96 h, over 90% substrate was consumed. Cellular biomass and lipid content were 14. 1 g/L and 55.7% for glucose culture, and 13.1 g/L and 52.6% for xylose culture. When grown on mixed sugar containing glucose （46.0 g/L） and xylose （24.0 g/L） under identical conditions, substrate consumption, biomass and lipid content were 75.1% , 15.0 g/L and 40.0% , respectively. Optimization was carried out with Plackett-Burman design and single factor experiments to improve microbial oil production with mixed sugar, leading to substrate consumption of 97.3 % after 96 h. Sugar consumption, cellular biomass, lipid content, biomass yield and lipid yield reached 99.5%, 19. 0 g/L, 52. 6%, 27% and 14%, respectively, under optimized conditions of substrate concentration of 70 g/L （glucose 46.0 g/L and xylose 24.0 g/L）, initial pH 6.0, inoculum concentration 10%, culture temperature 30 ℃ and incubation time 120 h.