Production, purification and characterization of a novel thermotolerant endoglucanase (CMCase) from Bacillus strain isolated from cow dung

Abstract

In an attempt to screen out cellulase producing bacteria from herbivorous animal fecal matter it was possible to isolate a potent bacterium from cow dung. The bacterium was identified as Bacillus sp. using 16S rDNA based molecular phylogenetic approach. The effect of different agricultural wastes, paper wastes and carboxymethyl cellulose on endoglucanase production was tested and was found to produce maximally at 8% carboxymethyl cellulose. The endoglucanase was precipitated by ammonium sulfate saturation and purified by DEAE- Sepharose column. The purification was achieved 8.5 fold from the crude extract with a yield of 68.1%. The molecular weight of the protein was determined to be 97 kDa by SDS-PAGE. The enzymatic activity was moderately reduced by detergents (SDS, Tween-80), metal ions (MnCl2, ZnCl2) and EDTA. The endoglucanase was stable between pH 5.0 – 9.0 and temperature between 20−70°C with optimal activity at pH 7.0 and temperature 50°C. The apparent Km value of the enzyme for the substrate carboxymethyl cellulose was recorded to be 0.25 mg/ml. The endoglucanase was stable in the presence of commercial detergents such as Ariel, Surf Excel and Tide, indicated might be of potential applications in detergent industry. The enzyme from this strain could also be applied in bioconversion of lignocellulosic biomass into fermentable sugars.

Current status of cow dung as a bioresource for sustainable development

“…Bacillus spp. from cow dung is capable of producing cellulose, carboxymethyl cellulose and cellulase (Das et al 2010;Sadhu et al 2013;Illavarasi 2014). In case of poor enzyme production, genetically improved strains can be constructed for enhanced enzyme production.…”

Production and characterization of endoglucanase secreted by Streptomyces capoamus isolated from Caatinga

“…The effect of several carbon sources on the cellulase production was investigated using different substrates (carboxymethyl cellulose, corn cobs and passion fruit residue). The choice of the cheapest and appropriate substrate is of great importance for the successful production of enzymes (Sadhu et al, 2013). The highest levels of extracellular cellulase activities were detected in medium supplemented with carboxymethyl cellulose (Figure 1).…”

Properties of <i>Bacillus</i> species Cellulase Produced Using Cellulose from Brewers Spent Grain (BSG) as Substrate

“…In another related study, a novel thermo-tolerant endoglucanase from Bacillus strains with the highest specific activity of 1.1 U/Mg proteins on utilisation of 8% carboxymethyl cellulose was reported [14].…”