Sugarcane bagasse saccharification using Aspergillus tubingensis enzymatic cocktail for 2G bio-ethanol production

In order to meet the increasing demand of 2G ethanol, sugarcane bagasse (SCB), a low cost by-product of sugarcane industry, can be utilized. However, cost-effective degradation of SCB into constituent fermentable sugars and subsequent ethanolic fermentation remains to be a far-fetched goal. In the present study, cellulase and hemicellulase cocktail produced by Aspergillus tubingensis NKBP-55 was applied for SCB hydrolysis under parametrically optimized conditions. Enzyme treatment (SCB: 7%, enzyme load: 1U = 1 mg) resulted in the liberation of fermentable mono-sugars 20 mg/mL (glucose, xylose and arabinose). Powder X-ray diffraction (PXRD) analysis revealed increase in the crystallinity index from 58.4 to 63.9% as a result of degradation of hemicellulose and amorphous cellulose. SCB hydrolysate was fermented to ethanol (0.415 g/g) by glucose and xylose-fermenting yeast, Candida shehatae NCIM 3501. Maximum ethanol concentration (15.54 +/- 0.3 g/L) with 77.9% fermentation efficiency and 0.161 g/L/h productivity was achieved. The present study revealed that A. tubingensis enzyme cocktail can be used for efficient SCB hydrolysis and conversion of resulting hydrolysate into bioethanol using C. shehatae. (C) 2020 Elsevier Ltd. All rights reserved.