Isolation and characterization of potential cellulose degrading bacteria from sheep rumen

Abstract

In the present study, cellulose degrading bacteria was isolated from sheep rumen. Screening of cellulose degrading bacteria was carried out based on CMC (carboxyl methyl Cellulose) hydrolytic test which was seen as clear zone around colony as well as whatsman filter paper degradation test. Twenty bacterial isolates with clearance zone diameter of >10mm on CMC agar were screened out for filter paper degradation test. Out of twenty isolates, only eight were able to digest filter paper and subjected to cellulase enzyme assay, microbiological analysis and molecular characterization. Cellulase enzyme was extracted from each isolate and enzyme activity assay was performed based on 3-5, dinitro- salcylic acid (DNS) method. Enzyme activity ranged from 0.225u/ml to 1.652u/ml in which maximum result was obtained in bacterial isolate labelled as KLCD08. Bacteriological study of the isolates showed that five isolates (KLCD04, KLCD012, KLCD15, KLCD18, KLCD19) belong to Bacillus species, two isolates (KLCD01, KLCD09.) Bacteriodes species and one isolate (KLCD08) Enterobacter pecies. Molecular characterization was applied to the isolate with greater cellulolytic activity (KLCD08) based on 16srRNA gene sequencing. According to phylogenetic analysis made by the use of EZBIocloud database, the isolate showed 99.84 % homology with Enterobacter cloacae subsp. Dissolvens. The sequence was deposited to NCBI GenBank with accession number of MN120893. The identified bacteria could be used for large scale production of cellulase enzyme through bio-processing technology. It can also be formulated as probiotics in animal nutrition.