ISOLATION AND SCREENING OF CELLULOLYTIC BACTERIA INHABITING GUT OF EISENIA FETIDA FED ON MUNICIPAL SOLID WASTE

Abstract: Cellulose is the most abundant biopolymer in nature and constitutes a large pool of carbon source for the microorganisms responsible for the decomposition of organic matter in soil. Earthworms influence this decomposition by enhancing the structure and dynamics of the microbial population inside their gut as an efficient bioreactor. The assessment of cellulolytic activity in the microbes isolated from the mid-gut of the popular composting earthworm, Eisenia fetida (Redworm), revealed the bacterial community is responsible for the breakdown of cellulose and thereby decomposition of organic matter by this earthworm. The bacterial counts for viable microorganisms were made in the mid-gut section of Eisenia fetida collected from vermicomposting unit. The number of bacteria present in the mid gut identified by standard plate count technique. Based on the morphological characteristics of colony, 3 cultures were raised. They were further screened for their cellulolytic activity in modified czapex-dox agar. Out of 3 cultures, only 2 cultures proved to be cellulolytic. Carboxy methyl cellulase assay was then performed to find out the most efficient cellulase producers. Accordingly, the culture designated as Cdb1 produced 26.041 ± 14.062 IU/ml and the culture designated as Cdb2 produced 47.800 ± 25.812 IU/ml of CMCase 0.1% substrate in 72hours at 37°C and at pH 7.

Keywords: Bacterial enzyme, Cellulose, Carboxy methyl cellulose, Earthworm Eisenia fetida.