Abstract

BIOETHANOL PRODUCTION FROM NAOH+H2O2 PRETREATED POPULUS DELTOIDES WOOD USING COCKTAIL OF INHOUSE AND COMMERCIAL ENZYMES UNDER FOUR DIFFERENT MODES OF SEPARATE HYDROLYSIS AND FERMENTATION

Nisha Sharma* and Nivedita Sharma

Abstract

In the present study the bioconversion of alkaline hydrogen peroxide pretreated P. deltoides wood by using cocktail of inhouse enzymes from Bacillus stratosphericus N12 (M), Myceliophthora thermophila SH1 and Bacillus altitudinis Kd1 (M) under submerged as well as solidstate fermentation was done which was compared with commercial enzymes. Comparative study of bioethanol production from P. deltoides wood was carried out using different methods of non-detoxification/detoxification, enzymatic hydrolysis and fermentation. In method I and II supernatant of alkaline hydrogen peroxide pretreated P. deltoides wood was pooled together with enzyme saccharified residue fraction, while in method III and IV supernatant after pretreatment was discarded and only enzymatic hydrolysate containing simple sugars was used for the fermentation. Different ethanologenic yeasts and bacteria were employed under monoculture and coculture combinations for fermentation. The highest ethanol yield of 18.47 g/l was obtained in method IV as compared to others and 21.41g/l in case of commercial enzymes. The co-culture of Saccharomyces cerevisiae II+ Pichia stipitis was found best combination of ethanologens in both cases i.e. in inhouse enzyme saccharified hydrolysate as well as by using commercial enzymes.

Keywords: Populus deltoides, Bioethanol, Monoculture, Co-culture.