No 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.

The goal was to investigate the cellulase enzyme production ability of bacterial strain C1 isolated from cow dung and identified as Bacillus sp. on the basis of 16 S rDNA sequence homology. The effects of different carbon sources like Carboxymethyl cellulose (CMC), avicel, starch, maltose, sucrose, glucose, fructose, galactose and lactose on cellulase production at varying environmental parameters of incubation period (2-10 days), temperature (35-55°C), and pH (6.0-8.5) were examined. The CMC was the best carbon source for cellulase production followed by lactose in this bacterial strain. The maximum enzyme production was achieved at a temperature of 50°C by Bacillus sp. with pH of 7.0 on the 8th day of growth. The nitrogen source NH 4 NO 3 at 0.175% was optimum for cellulase production by this bacterium. A putative mutant (C1M 26 ) was screened from wild C1 strain after mutagenesis with N-methyl-N 0 -nitro-N-nitrosoguanidine (NTG) as a mutagenic agent. The mutant C1M 26 produced a larger amount of cellulase in comparison to wild type C1 strain. ª 2014 Production and hosting by Elsevier B.V. on behalf of King Saud University.

A cellulase-producing bacterial strain designated Z5 was isolated from the fecal matter of Zebra (Equus zebra). The strain was identified as Microbacterium sp. on the basis of 16S rDNA sequence analysis. The effect of substrates like CMC, avicel, starch, maltose, sucrose, glucose, fructose, galactose, and lactose on cellulase production was also determined. Lactose as the sole carbon source induced cellulase production in this bacterial strain and a positive synergistic effect of lactose and CMC was also observed with enhancement of 3-4 times in cellulase activity. The optimum cellulase production was recorded with 3% CMC and 1% lactose when added individually in the Omeliansky's medium. The optimum temperature and time for cellulase production by this bacterial strain was 37°C and 10 days, respectively. To our knowledge this is the first report on enhancement of cellulase production by lactose in the Microbacterium sp.

A cellulase producing bacterium (E3 strain) was isolated from fecal matter of elephant and identified as Bacillus sp. using 16S rDNA sequenced based molecular phylogenetic approach. While studying the effect of substrates like Carboxymethyl cellulose (CMC), avicel, starch, maltose, sucrose, glucose, fructose, galactose and lactose on cellulase production, it was found that CMC was best carbon source induced cellulase production followed by lactose in this bacterial strain. A positive synergistic effect of lactose with CMC was also observed with enhancement of 5 -6 times in cellulase production. The optimum cellulase production was recorded with 1% CMC and 1% lactose when added individually in the Omeliansky's medium. The results showed that addition lactose with CMC greatly enhances the production and activity of various cellulase enzymes. The optimal fermentation conditions for the biosynthesis of cellulase by this strain were found to be temperature: 37˚C, pH 7.0. The nitrogen source NH 4 Cl at 0.15% was optimum for cellulase production by this bacterium.