Optimization and strain improvement by mutation for enhanced cellulase production by Bacillus sp. (MTCC10046) isolated from cow dung

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 NH4NO3 at 0.175% was optimum for cellulase production by this bacterium. A putative mutant (C1M26) was screened from wild C1 strain after mutagenesis with N-methyl-N′-nitro-N-nitrosoguanidine (NTG) as a mutagenic agent. The mutant C1M26 produced a larger amount of cellulase in comparison to wild type C1 strain.