Screening of oleaginous microorganisms for microbial lipids production and optimization

To screen potential oleaginous microorganisms for production of microbial lipid, thirty-one yeast strains from forest soils collected from Hunan Province, China, were tested for their potentiality to produce microbial lipid, and fourteen potential strains were further screened. The results showed that yeast strain SCIM 2.012 displayed the most potential ability in producing microbial lipid, the lipid content of cells reached 52.4%, and the lipid yield was 7.8±0.54 g/L. Furthermore, the components profile of the lipid was analyzed. The results suggested that the lipid was abundant in low degree unsaturated long chain fatty acid (C18: 1) and saturated long chain fatty acids (C16: 0), suggesting the lipid could be used for biodiesel production. The optimized media for lipid production from strain SCIM 2.012 were as the follows: Sucrose as carbon source with initial concentration 100 g/L, NH4NO3 as nitrogen source at 3.5 g/L, the initial pH was 6.0. With the optimized media, the lipid content of cells highly reached 56.7%, the lipid yield was 9.7±0.67 g /L, and biomass was 17.1±0.37 g/L.