Co-production of microbial oil and exopolysaccharide by the oleaginous yeast grown in fed-batch culture.

The production cost of microbial oil was reduced by improving the exopolysaccharide (EPS) production to share the production cost using JD-2. Batch fermentation demonstrated that JD-2 has the potential to co-produce oil and EPS with 120 g L glucose, 20 g L corn steep liquor and 10 g L yeast extract as carbon and nitrogen sources. Using fed-batch fermentation for 72 h resulted in oil and EPS production of 41.6 ± 2.5 g L and 13.1 ± 0.6 g L with the productivity of 0.58 g L h and 0.182 g L h, respectively. The fat soluble nutrients in the oil were studied, indicating that it was constituted of 79.19% unsaturated fatty acids and contained 505 mg per kg-oil of carotenoids. Moreover, the EPS contained only one type of polysaccharide; the main monosaccharide compositions were galactose, glucose and mannose in a proportion of 16 : 8 : 1. These results implied that EPS produced by JD-2 was a new type of EPS.