Isolation and Screening of Cellulose Hydrolyzing Bacteria from Different Ecological Niches

Abstract

371 bacteria were isolated from different ecological niches. Cellulolytic potential of the isolates was evaluated by qualitative as well as quantitative screening methods. 124 bacterial cultures showed production of zone of hydrolysis in the plate assay method. The hydrolytic potential of the isolates measured in terms of cellulolytic index indicated that 84 isolates showed cellulolytic index (CI) values between 1 and 4, 22 isolates between 4 to 6 and 18 isolates in the range of 6 to 13. The positive isolates with CI values ≥4.0 were screened quantitatively for the production of cellulases, determined as carboxy methyl cellulase (CMCase) activity and filter paper activity (FPase). Comparison of the activities shown by the isolates with that recorded in the standard isolate of Cellulomonas fimi indicated that large number of bacteria produced considerably high amounts of cellulases. The isolate NAB37 showed highest levels of CMCase (0.948±0.011 U/ml) as well as FPase (0.125±0.005 FPU/ml) activities. The cellulolytic potential of the bacteria can be exploited in various cellulases based applications including detergents, textile, paper and pulp, food and bioethanol industries.