Saccharification of the pretreated husks of corn, peanut and coffee cherry by the lignocellulolytic enzymes secreted by Sphingobacterium sp. ksn for the production of bioethanol

Abstract

The present work emphasizes to develop a cost-effective process for the saccharification of lignocellulosic agro-wastes viz., husks of corn, peanut and coffee cherry, utilizing the consortium of crude lignocellulolytic enzymes produced by the newly isolated Sphingobacterium sp. ksn followed by fermentation process with yeast strains. The agro-residues were subjected for steam pretreatment before enzymatic hydrolysis and compared with NaOH or H2SO4 pretreatments. Corn husk was found to be the best substrate for enzymatic hydrolysis for the production of fermentable sugars. The Saccharomyces cerevisiae and Candida tropicalis were employed individually or as co-culture for fermentation of the hydrolysate obtained after enzymatic breakdown of steam treated agro-residues. The maximum ethanol produced by utilizing enzymatic hydrolysate of the steam treated husk of corn as substrate by separate hydrolysis and fermentation were 20.61, 5.81 and 18.21 g L?1 respectively, whereas 20.66 and 5.85 g L?1 were acquired from the corresponding immobilized yeast cells after 72h of fermentation. © 2019 Elsevier Ltd