皮状丝孢酵母B3利用木薯淀粉发酵生产微生物油脂

Microbial oil production by Trichosporon cutaneum B3 using cassava starch

摘要:

对皮状丝孢酵母B3以木薯淀粉水解液为碳源发酵生产微生物油脂培养条件进行了优化，并在2 L发酵罐中对菌体生长和油脂积累进行了考察。摇瓶实验表明，木薯淀粉水解液的浓度高于90 g/L时不利于菌体的生长和油脂积累，皮状丝孢酵母B3发酵生产微生物油脂的最适氮源及其浓度、最适C/N比和pH分别为酵母提取物3.0 g/L、116、6.0，在此条件下培养144 h菌体生物量、油脂产量和油脂含量分别达到15.2 g/L、6.22 g/L和40.9％；在2 L发酵罐中分批发酵44 h后菌体生物量、油脂产量和油脂含量分别达28.7 g/L、12.27 g/L和42.8％。以皮状丝孢酵母B3所产油脂制备生物柴油，其主要组成包括棕榈酸甲酯、硬脂酸甲酯、油酸甲酯、亚油酸甲酯等，且理化特性符合相关国家标准，可作为一种有潜力的化石燃料替代品。

Abstract:

Microbial oil, as raw material for biodiesel, can be produced by Trichosporon cutaneum B3 using cassava starch hydrolysate. Batch cultures demonstrated that there was little inhibitory effect with the concentration of cassava starch hydrolysate up to 90 g/L. The favorable initial pH, C/N molar ratio, nitrogen source and its concentration were 6.0, 116, yeast extract and 3.0 g/L, respectively. Under the optimized conditions, dry biomass reached 15.2 g/L and lipid content reached 40.9% after culture for 144 h in flask. Batch cultures in a 2 L stirred-tank fermenter were run for 44 h and resulted in dry biomass, lipid content and lipid yield of 28.7 g/L, 42.8% and 12.27 g/L, respectively. The chemical compositions of biodiesel prepared from lipids of T. cutaneum B3 mainly included palmitic acid methyl ester, stearic acid methyl ester, oleic acid methyl ester and linoleic acid methyl ester etc., and its main physicochemical properties were in compliance with relevant national diesel standards. Therefore, the biodiesel prepared from lipids of T. cutaneum B3 can serve as a potential fossil fuel alternatives.