Microbial degradation of lobster shells to extract chitin derivatives for plant disease management

Abstract

Chitinolytic microorganisms are an environment safe approach to utilize lobster processing wastes and extract chitin derivatives from lobster shells. Two microbes, “S223” and “S224” isolated from soil samples exhibited significant levels of deproteinisation, demineralisation of lobster shells and chitinolysis among ten microorganisms screened. Their culture conditions were optimized for factors influencing efficient degradation of lobster shells and chitinase was purified (∼30 kDa) from crude extract by affinity chromatography. Morphological observations and 16S rDNA sequencing resolved that the isolates belong to Streptomyces genus. The digested lobster shell extracts induced disease resistance in Arabidopsis, which was determined by the increased levels of enzyme activity and expression of defence related genes (PR1 > 500 fold, PDF1.2 > 40 fold) upon Pseudomonas syringae and Botrytis cinerea infection. The study strongly suggests that soil microbial diversity aid in the sustainable bioconversion of lobster shells and the chitin derivatives extracted could be applied in plant protection.