Sweet sorghum syrup as a renewable material for microbial lipid production

Cryptococcus curvatus, an oleaginous yeast strain was observed to grow on sweet sorghum syrup derived from sorghum juice. In a batch cultivation mode, within the tested range of total sugar concentrations from 11.7 to 34.0. g/L, no substrate inhibition to cell growth was detected. C. curvatus utilized glucose, fructose, and sucrose sequentially. In a fed-batch process, howev)er, this yeast consumed the three sugars more rapidly and simultaneously. Within three days, a biomass density of 23.6. g/L was obtained. The overall lipid productivity was 4.0. g/L-day. Through use of microwave-assisted lipid extraction, 78.1% of available lipid was extracted out of C. curvatus cells in 4. min using methanol as the only solvent. This study demonstrated that fermentation of C. curvatus using sorghum syrup will result in high lipid yield.