School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, 947 Heping Road, Wuhan, 430081, People's Republic of China.
State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China.
Appl Biochem Biotechnol. 2022 Jul;194(7):2968-2979. doi: 10.1007/s12010-022-03903-x. Epub 2022 Mar 22.
Direct bioconversion of high concentration of volatile fatty acids (VFAs) into microbial lipid is challenging due to the aggravated cytotoxicity of VFAs at high loadings. Herein, a robust oleaginous yeast Trichosporon cutaneum was screened for lipogenesis from high concentration of VFAs using a regular batch culture. Biomass and lipid content of 8.9 g/L and 49.1%, respectively, were attained from 50 g/L acetic acid with 90.9% of which assimilated within 10 days. The blend of VFAs (50 g/L), with mass ratio of acetic, propionic, and butyric acids of 6:3:1, was found superior to acetic acid for lipogenesis. Biomass and lipid titer increased by 16.9% and 18.2%, respectively, with the three VFAs completely consumed within 8 days. Butyric acid was assimilated simultaneously with acetic acid at the beginning of the culture. Heptadecanoic acid (C17:0) and heptadecenoic acid (C17:1) were produced when propionic acid co-existed with acetic and butyric acids. The estimation of biodiesel properties indicated that lipid prepared from VFA blend showed superiority to acetic acid for high-quality biodiesel production. This study strongly supported that T. cutaneum permitted high concentration of VFA mixture for lipid production.
由于高浓度挥发性脂肪酸（VFAs）的细胞毒性加剧，直接将其生物转化为微生物油脂具有挑战性。在此，通过常规分批培养，筛选出一种具有强大产油能力的油脂酵母——毛孢子菌（Trichosporon cutaneum），用于从高浓度 VFAs 中合成油脂。该酵母可以从 50g/L 的乙酸中获得 8.9g/L 的生物量和 49.1%的脂质含量，其中 90.9%的乙酸在 10 天内被同化。发现混合 VFAs（50g/L），其中乙酸、丙酸和丁酸的质量比为 6:3:1，比乙酸更有利于产油。生物量和脂质产量分别提高了 16.9%和 18.2%，在 8 天内三种 VFAs 完全被消耗。丁酸在培养初期与乙酸同时被同化。丙酸与乙酸和丁酸共存时会产生十七烷酸（C17:0）和十七碳烯酸（C17:1）。生物柴油性质的评估表明，与乙酸相比，来自 VFA 混合物的油脂更有利于生产高质量的生物柴油。这项研究有力地支持了毛孢子菌可以耐受高浓度的 VFA 混合物用于油脂生产。
