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为高效利用水稻秸秆中的纤维素和半纤维素产油脂,采用稀酸预处理和酶水解两步法对水稻秸秆进行水解,然后以水解液为碳源,培养发酵性丝孢酵母Trichosporon fermentans HWZ004产微生物油脂。结果表明,经简单overliming法脱毒后水稻秸秆水解液中乙酸、糠醛和5-羟甲基糠醛的浓度分别为0.4 g/L、0.1 g/L和0.05 g/L。只需添加少量氮源和微量CuSO4.5H2O,该水解液即可满足T.fermentans HWZ004发酵产油脂的要求。发酵最适接种量、初始pH和温度分别是5.0%、7.0和25℃。T.fermentans HWZ004在优化条件下培养7 d的生物量、油脂含量和油脂产量分别是26.4 g/L,52.2%和13.8 g/L;油脂得率系数为17.0,大大高于驯化前菌株T.fermentans CICC 1368在脱毒水稻秸秆半纤维素水解液中的对应值(11.9)。所产油脂的脂肪酸组成与植物油相似,不饱和脂肪酸含量达70%以上,宜作为生物柴油的生产原料。
In order to make efficient use of the cellulose and hemicellulose-producing oil in rice straw, the straw was hydrolyzed by two steps of dilute acid pretreatment and enzymatic hydrolysis, and then the hydrolyzate was used as carbon source to culture Trichosporon fermentans HWZ004 Microbial fat production. The results showed that the concentrations of acetic acid, furfural and 5-hydroxymethylfurfural in rice straw hydrolyzate were 0.4 g / L, 0.1 g / L and 0.05 g / L, respectively, after detoxification by simple overliming method. Just add a small amount of nitrogen and trace CuSO4.5H2O, the hydrolyzate to meet T.fermentans HWZ004 fermentation fat production requirements. The optimum amount of fermentation inoculation, initial pH and temperature were 5.0%, 7.0 and 25 ℃. T.fermentans HWZ004 was cultured under optimum conditions for 7 days and its lipid content and oil yield were 26.4 g / L, 52.2% and 13.8 g / L, respectively. The coefficient of yield of oil was 17.0, much higher than that of domesticated strain T. Corresponding value of fermentans CICC 1368 in detoxified rice straw hemicellulose hydrolyzate (11.9). The fat composition of fat and vegetable oil similar to unsaturated fatty acid content of more than 70%, should be used as raw material for the production of biodiesel.