Bioconversion of corncob hydrolysate into microbial lipid by an oleaginous yeast Rhodotorula taiwanensis AM2352 for biodiesel production

Corncob is a kind of abundant lignocellulosic biomass. One of the bottlenecks in utilization of corncob in fermentation industry is many microorganisms cannot ferment xylose, which is the main component of corncob hydrolysate. Here we identified a novel oily yeast strain AM2352 of Rhodotorula taiwanensis, which could effectively convert corncob hydrolysate into microbial lipid. Notably, the fatty acid synthase alpha-subunit of R. taiwanensis has two acyl carrier protein (ACP) domains, which may be involved in high-level oil contents in its cells. Based on a 5-L fermentation analysis, the coefficient of lipid production was 55.8 g oil per kilogram of corncob. Long-chain fatty acids (C16-C18) were the main components of the intracellular lipid accumulated by the yeast strain AM2352. Over 81.5% of the extracted oil could be converted into biodiesel. This work not only provides an inspiring information into the utilization of corncob hydrolysate by the yeast strain AM2352 for microbial lipid production, but also probably promotes biofuel production. (C) 2020 Elsevier Ltd. All rights reserved.