Effect Of Carbon Sources On Cellulase Producing Activity Of Bacterial Isolates
Cow dung and municipal solid wastes have been selected as cellulolytic bacterial habitants. Nine bacterial strains designated as cd1, cd2, cd3, cd4, mw1, mw2, mw3, mw4 and mw5 were isolated and screened the cellulolytic activity on Berg’s media containing 1%carboxymethyl cellulose (CMC) and cellulose substrate. Six strains showed the halo zone formations which indicate the cellulolytic activity. Among cd strains, cd3 was more effective on cellulolytic activity. On the other hand, mw4 was also potentially more effective. For both carbon sources, they showed the highest halo zone diameters with 30mm and 15mm. The two strains have been studied for quantitative determination of cellulolytic activities by DNS method. CMC and cellulose were used as inducer substrates for cellulase enzyme. In CMC broth, the enzyme producing of cd3 and mw4 showed the reducing sugar formation 1.7mg/ml and 1.677mg/ml when the crude enzyme react with 1% cellulose solution. In cellulose broth, they showed the reducing sugar formation in 0.562mg/ml and 0.415mg/ml. The optimal incubation period for cellulase enzyme producing was 36hr and 60hr for cd3 and mw4 in CMC broth but 84hr and 60hr were the optimal incubation period in cellulose broth. The selected strains were more favour CMC than cellulose for the producing activity of cellulase enzyme..
Keywords- Bacteria, Cellulose, CMC, DNS, Enzyme, Quantitative, Screening