Detection of chitinase activity and its characterization from Pseudomonas fluorescens of tea rhizosphere

摘要

Rhizosphere soil was used for the isolation of chitin-degrading bacteria that produce chitinase enzyme with pesticidal activity. The use of chitinase from bacterial biocontrol agents instead of spraying whole organism to control insect pests is an attractive field of biotechnological research. Chitin (CgH|305N)n, an insoluble, most abundant polysaccharide is composed of linear chains of pM ,4-N-acetylglucosamine (GlcNAc) residues that are highly cross-linked by hydrogen bonds. Chitin is widely distributed in nature and it is the principle structural component of outer skeleton (50% of the cuticle made up of chitin), foregut, hindgut and midgut lining of peritrophic membrane and essential for structural integrity of many insects, nematodes and most of the fungi (Bhattachrya et al, 2007; Park et al., 2011). Chitinase degrade chitin into its monomelic or oligomeric components, hence, it might be speculated that if applied on to the insect, either it enters the gut of insect larvae causing significantdamage to the peritrophic membrane structure, which restricts feeding activity, leading to its death.