Optimization of lipids production by Cryptococcus laurentii 11 using cheese whey with molasses

This study aimed the optimization of culture condition and composition for production ofCryptococcus laurentii 11 biomass and lipids in cheese whey medium supplemented with sugarcanemolasses. The optimization of pH, fermentation time, and molasses concentration according to a fullfactorial statistical experimental design was followed by a Plackett-Burman experimental design,which was used to determine whether the supplementation of the culture medium by yeast extract andinorganic salts could provide a further enhancement of lipids production. The following conditionsand composition of the culture medium were found to optimize biomass and lipids production: 360 hfermentation, 6.5 pH and supplementation of (g L-1): 50 molasses, 0.5 yeast extract, 4 KH2PO4, 1Na2HPO4, 0.75 MgSO4•7H2O and 0.002 ZnSO4•H2O. Additional supplementation with inorganicsalts and yeast extract was essential to optimize the production, in terms of product concentration andproductivity, of neutral lipids by C. laurentii 11. Under this optimized condition, the production of totallipids increased by 133% in relation to control experiment (from 1.27 to 2.96 g L-1). The totallipids indicated a predominant (86%) presence of neutral lipids with high content of 16- and 18- carbon-chain saturated and monosaturated fatty acids. This class of lipids is considered especially suitablefor the production of biodiesel.

Uncontrolled Keywords

Cryptococcus laurentii, microbial lipids, cheese whey, sugarcane molasses, biodiesel.