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

• Published in: Biomass & bioenergy 2019-08, Vol.127, p.105298, Article 105298
• Main Authors: Shankar, Kumar, Kulkarni, Neelkant S., Jayalakshmi, S.K., Sreeramulu, Kuruba
• Format: Article
• Language: English
• Subjects: Bioethanol; Enzymatic hydrolysis; Fermentable sugars; Lignocellulosic agro-wastes; Sphingobacterium sp ksn
• ISSN: 0961-9534; 1873-2909
• DOI: 10.1016/j.biombioe.2019.105298

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. •Enzymatic hydrolysis of steam, acid and alkali treated agro-residues were compared.•The steam treatment was best method for agro-residues before enzymatic hydrolysis.•The maximum ethanol was produced using corn husk as a substrate by S. cerevisiae.•The immobilized beads of yeast may be used upto four cycles for ethanol production.