Advances in Recycling & Waste Management

Optimization of Ethanol Production from Enzymatic Hydrolysate of Maize Stover

Abstract

Harshvadan Patel, Jyoti Divecha and Amita Shah

For efficient bioethanol production from maize stover, fermentation of glucose and xylose both was attempted using Saccharomyces cerevisiae and Pichia stipitis sequentially from enzymatic hydrolysate of mild alkali treated maize stover. Enzymatic saccharification of mild alkali treated maize stover at high substrate (30%) loading using 13.0 FPU/g commercial cellulase (MAPs 450) and 74.42 U/g crude β-xylosidase (Inhouse produced) after 36 h, yielded 161.32 mg ml-1 reducing sugars. Ethanol production was optimized employing response surface methodology. Under optimized conditions viz. 5% glucose, 14.55% inoculum and Time 35.51 h; 90.65% glucose was utilized and produced 18.93 g l-1 ethanol with 0.53 g l-1 h-1 productivity by Saccharomyces cerevisiae NCIM 3524. Further attempts were made to produce ethanol from xylose present in enzymatic hydrolysate using Pichia stipitis NCIM 3497. However, xylose conversion was not satisfactory as only 71% xylose was utilized.