Isolation and purification of cellulase from alkaline-tolerant Bacillus subtilis

Abstract

Lignocellulosic biomass is one of the most abundant renewable resource in the world. It has high potential to be used as material for biorefinery process because it yields fermentable sugar that can be converted to various bioproducts via microorganism functions. To make the biorefinery process success, the efficient hydrolysis process is needed to be improved to release the maximum amounts of sugars from lignocellulosic biomass. Natural environment is an important source to find an efficient cellulase producing bacteria. Previously, an alkaline-tolerant cellulase-producing bacterium, Bacillus subtilis strain MSB9, was screened and isolated from Botanic garden in Mahasarakham province, Thailand. In this study, we focused on the purification and characterization of cellulase enzyme produced by B. subtilis strain MSB9. The crude cellulase enzyme was partially purified and concentrated by ammonium sulfate precipitation and fractionated by using size exclusion chromatography using sephacryl S-100 HR column. Two of purified cellulase have relative molecular mass of 35 and 45 kDa, as determined by SDS-PAGE combined with CMC-zymogram.