Bioprospecting for extracellular hydrolytic enzymes from culturable thermotolerant bacteria isolated from Manikaran thermal springs.

Abstract

Microbial enzymes play a major role in hydrolysis oflignocellulosic compounds to fermentable sugars. Inorder to isolate thermotolerant bacterial isolates in Manikaran hot springs having potential to produceextracellular hydrolytic enzymes were analyzed usingdifferent nutrient combinations. Of 120 isolates,twenty strains showed hydrolytic enzymes productionat >70  C. Phylogenetic analysis of positive strains,based on 16S rDNA sequences indicated that isolateswere clustered within 48% Proteobacteria, 33%Firmicutes and 19% Actinobacteria. Evaluation ofhydrolytic enzymes production under submerged andsolid state fermentation was done using paddy strawas sole carbon source. Out of twenty, seven bacterialisolates were found to be novel and efficient for the production of hydrolytic enzymes. A large variation was observed among differentisolates for hydrolytic enzymes production. Sevenisolates Lysinibacillus sp. ,

Enterobacter cloacae, Rhodococcus qingshengii, Paenibacillus pabuli, Bacillus pumilus, Micrococcus indicus and Pseudomonas fragi

based on their maximum production on all different temperature especially70°C were evaluated in terms of enzyme propertiesand kinetics. The enzyme of above seven isolates isactive over broad range of high temperature. Suchthermo stable isolates have potential to be used todevelop as consortia for bioconversion oflignocellulosic residue to fermentable sugars preferably at high temperature.