Fermentation of Enzymatically Saccharified Groundnut shell for Fuel Ethanol Production by Pichia stipitis NCIM 3498

Ethanol production was evaluated from Groundnut shell (GS), a readily available potential feedstock, for production of fermentable sugars. Sodium hydroxide pretreated GS was enzymatically saccharified (50°C, pH 5.0, 50 h) using cellulolytic enzyme cocktail (cellulase, xylanase, β–glucosidase etc.) from a novel isolate, Aspergillus sp. RCAL-5. It showed cellulolytic enzyme production (Filter paperase (FPase) 0.86 U ml⁻¹, Carboxy methyl cellulase (CMCase) 1.25 U ml⁻¹, β-glucosidase 1.68 U ml⁻¹ and xylanase

4.57 U ml⁻¹) after 4 days of incubation at 28°C using delignified wheat bran as a carbon source. The maximum yield of monomeric sugars from delignified substrate was 0.64 g g⁻¹ with a saccharification efficiency of 63.12%. The fermentation performance of Pichia stipitis NCIM3498 was assessed using GS enzymatic hydrolysate (49 g l⁻¹ sugars) for ethanol production in 10 l fermenter. A maximum of ethanol production (19.4 g l⁻¹) was obtained with a yield

(0.46 g g⁻¹ sugar utilized) and productivity (0.23 g _l-1 _h-1_).