Efficient Conversion of Rice Straw Holocellulose into Microbial Lipid by Cryptococcus curvatus O3

Efficient microbial lipid conversion from rice straw holocellulose hydrolysate (RSHH) by Cryptococcus curvatus O3 was first performed. Fermentation from RSHH without detoxification gave a lipid production of 6.72 g l–1, much higher than the result with glucose (4.74 g l–1. RSHH detoxification by active carbon adsorption led to significant improvement of biomass and lipid production. The maximum biomass of 21.19 g l–1 containing 10.09 g l–1 of lipid could be achieved by using detoxified RSHH. The accumulated lipids RSHH were mainly constituted by palmitic acid, stearic acid and oleic acid. Additionally, unsaturated and unusual long-chain fatty acid production was significantly increased. After culture parameter optimization, the highest lipid yield of 11.84 g l–1 and lipid content of 54.07% were obtained with the detoxified RSHH. This research established an essential strategy for efficient microbial lipid accumulation from RSHH.