Valorization of agri-wastes through microbial consortia and its conversion into bioethanol by co-fermentation method using Saccharomyces cerevisiae NCIM 3594 and Pichia stipitis NCIM 3497 strains

This study aimed to describe the valorization four agri-wastes: paddy straw, wheat straw, corn cobs and sugarcane bagasse through the microbial consortia (bacterial and fungal) followed by fermentation of reducing sugars into bioethanol through yeast strains Saccharomyces cerevisiae NCIM 3594 and Pichia stipitis NCIM 3497. The saccharification of alkali-treated biomass was performed by utilizing microbes (bacterial and fungal) under the submerged conditions at 35 and 30 °C, 150 rpm for 10 days. Saccharification of biomass revealed that the maximum reducing sugar was obtained from alkali pretreated corn cobs and wheat straw through the fungal and bacterial hydrolysis, respectively The results of fermentation study showed that fungal hydrolysates yielded 1.27 fold more bioethanol compared to the bioethanol produced from bacterial hydrolysate with a bioethanol production efficiency of 80.46 %.