Microbial lipid production by Cryptococcus curvatus from vegetable waste hydrolysate.

This study primarily evaluated the effect of pre-treatment on release of reducing sugars (RS) from vegetable waste (VW). Different acids and alkalis viz., H2 SO4 , HCl, HNO3 , H3 PO4 , NaOH and KOH were evaluated at varied concentration (0.5, 1.0, 1.5 and 2.0%) for pretreatment. The highest RS yield of 472.36 ± 1.89 g/l and 439.13 ± 1.04 g/l was obtained with 1.5% H2 SO4 and 2% HCl respectively. Secondly, pre-treated vegetable waste hydrolysates (PT-VWH) were evaluated for yeast fermentation using Cryptococcus curvatus MTCC 2698 for lipid production. Maximum biomass (9.46 ± 0.1 g/l and 8.12 ± 0.1 g/l) and lipid (28.3 ± 0.5% and 26 ± 0.5%) was obtained with 1.5% H2 SO4 PT-VWH and 2% HCl PT-VWH respectively. The FAME profiling revealed the predominance of palmitic, stearic, oleic and linoleic acid. The presence of these fatty acids in majority has beneficial effect on the biodiesel quality.