Isolation, Identification And Characterization Of A Cellulase-producing Strain

Cellulose is one of the most abundant renewable resource utilization in the industrial and agricultural produce if it will have a huge positive effect, but it was difficult to degrade that cellulose utilization is limited. In recent years, the degradation of cellulose has a lot of aspects of the research report, and the most economical method and environmentally friendly biodegradable by microorganisms that produce cellulase enzymes catalyze the degradation of cellulose.In this study, the sole carbon source of enrichment medium was used to enrich the microorganism cultures. CMC-Na medium was used to screen the cellulose-degrading strains, Four cellulose-degrading strains were isolated and purified using LB medium. Through filter paper disintegration and enzyme activity assay the ability to obtain a relatively high enzyme production strains KZ-2. The bacteria is Gram-negative bacteria, facultative anaerobic. Followed by identification utilizing morphological, physiological and biochemical properties, and 16S rRNA gene sequence profiles, it was identified as Enterobacter sp., its highest homology is Enterobacter aerogenes, and potentially to be a novel species.Experimental study on bacteria in the fermentation medium conditions incubation time by a single factor, temperature, initial pH, the effect of initial NaCl concentration on the bacteria enzyme production, test results show that the bacteria in the fermentation medium for enzyme production reached 5 days maximum, at 25-35 ℃, initial pH 4.5-5.5, optimum fermentation conditions NaCl concentration within the range of 1.0%-2.0%, the activity reached 80.93 U/mL. By orthogonal experiment to optimize fermentation conditions after fermentation broth CMCA enzyme activity and FPA were 108.53 U/mL and 82.36 U/mL.The bacteria produced by univariate study of cellulose enzymatic properties. The results showed that the strain produced in a neutral cellulase enzyme having a high activity under the conditions of 50 ℃.In the chloride salts on the KZ-2 production of cellulase obvious, KCl and FeCl3 on the enzyme activity promoted, CuCl2 and ZnCl2 inhibition of enzyme activity, MgCl2 does not have much impact on the enzyme activity. KZ-2 strain of cellulase production of these properties it offers good prospects for the use of neutral cellulase in the development process, it is worth further study.