一株丝孢酵母属菌株发酵产油脂的研究

摘要

The lipid productions of Trichosporon sp. JM-B under different nutrition and fermentation con-ditions were compared by flask fermentation. With cell biomass, lipid productivity, lipid content and lip-id coefficient as indexes, the composition of fermentation medium including mass concentration of carbon source, composition and mass concentration of nitrogen source and mass concentration of phosphate, and fermentation conditions including inoculation amount,fermentation temperature, shaker speed and fermen-tation time were optimized, and the fatty acid composition of the lipid was determined by gas chromatogra-phy. The results showed that the optimal composition of fermentation medium was obtained as follows:glucose 100 g/L, ammonium sulfate 1. 0 g/L, yeast extract 10 g/L, potassium dihydrogen phosphate 4 g/L, natural pH;the optimal fermentation conditions were obtained as follows:fermentation temperature 25℃, shaker speed 160 r/min,seedage of seed liquid 36 h, inoculation amount 10%( based on the vol-ume of broth) and fermentation time 144 h;under the optimal conditions, the cell biomass and lipid pro-ductivity were the highest, reaching 16. 14 g/L and 6. 64 g/L, respectively;compared with the lipid ob-tained under the initial culture conditions, the lipid productivity under the optimal culture conditions im-proved by 161 . 4%, while the content of saturated fatty acids in the lipid decreased by 28 . 1%. There-fore, Trichosporon sp. JM-B could be considered as a strain with great potential for producing lipid.%通过摇瓶发酵,比较丝孢酵母属菌株JM-B在不同营养和发酵条件下的产油脂情况。以菌体生物量、油脂产量、油脂含量及油脂系数为指标,优化碳源质量浓度、氮源组成与质量浓度、磷酸盐质量浓度等发酵培养基组成,优化接种量、发酵温度、摇床转速、发酵时间等发酵条件,利用气相色谱法测定油脂脂肪酸组成。结果表明：最适培养基组成为葡萄糖100 g/L,硫酸铵1.0 g/L,酵母膏10 g/L,磷酸二氢钾4 g/L,pH自然；最适发酵条件为发酵温度25℃,摇床转速160 r/min,种子液种龄36 h,接种量10%(以发酵液体积计),发酵时间144 h。在最适培养条件下,得到的菌体生物量和油脂产量最高,分别为16.14、6.64 g/L,油脂产量较优化前提高了161.4%,油脂中饱和脂肪酸含量比优化前降低了28.1%。可以认为丝孢酵母属菌株JM-B是一株很有开发潜力的产油脂菌株。