Marine sponge Callyspongia diffusa associated with Pseudomonas fluorescens BCPBMS-1 was isolated from Madapam Coast, Tamil Nadu, India and screened for chitinase production. Chitinase was tested for its biocontrol activity against phytopathogenic fungi. Chitinase is an enzyme capable of hydrolyzing chitin, an insoluble polysaccharide present in the cell wall of higher fungi, insect gut walls and nematodes. Chitinase was extracted and purified by ion exchange chromatography using DEAE Sephadex A-50 column. Purified sample was found to be a protein with a molecular weight of 65 kDa. Both partially purified and purified chitinase were tested for their inhibitory activity against fungal pathogens. Among the fungal pathogen, maximum inhibitory activity was observed with Botrytis cinerea. Hence, it can be used as a potential biocide against Botrytis diseases in crops.

Keywords: Marine sponge, Pseudomonas fluorescens, chitinase, biocide, botrytis.