Exploration of Thermophilic Lignocellulolytic Enzymes Producing Bacterial Strains from Hot Springs of Western Himalayan Range

Abstract

The increased demand of energy across the globe has led us to rely on biofuels which are nowadays presenting an ideal contender to meet energy requirements in ultimate sustainable manner. Nowadays lignocellulosic biomass (LCB) is a promising source for energy production and also for maintaining sustainable environment. Lignocellulolytic enzymes are dynamically used to develop an environmental friendly and economic biological technique for degradation of LCB leading to secretion of different value added products. There is scarce availability of microbial strains which secretes all types of enzymes required for the complete hydrolysis of LCB. Thus, the formulation of effective and economic enzyme cocktail for LCB hydrolysis is major research platforms within biorefinery. In this study thermophiles were isolated from hot springs of Western Himalayan Range (Manikaran, Manali and Kasol, Himachal Pradesh) using CMC agar media at 55 °C, pH 7.0 under shaking (180 rpm). Out of total 23 isolated thermophilic bacterial strains, 5 bacterial strains (NIBE9, NIBE 10, NIBE 11, NIBE 13 and NIBE 23) displayed an ability to utilize cellulose and hemicellulose. The enzyme activity and specific activity was calculated with reference to standard curve of DNS and BSA for protein. Potent extracellular and cell bound cellulase activity was detected. The 16S rRNA analysis revealed that strain NIBE 9, NIBE 11, NIBE 13 and NIBE 23 showed 99.86%, 100%, 99.86% and 99.93% similarity with Bacillus licheniformis. The isolate NIBE 10 showed 100% similarity with Bacillus smithi. Evolutionary distances and clustering were based on the neighbor joining and maximum-likelihood method.