Functional characterization of bacteria isolated from different gut compartments of white grub, Anamola dimidiata, larvae

Abstract

Aim: The aim of the present study was to isolate and characterize cellulolytic, lipolytic and nitrate reductase activities in the bacteria isolated from the gut of white grub, Anamola dimidiata larvae Methodology: Field collected third instar scarab larvae were dissected under aseptic conditions and inoculated on different bacteriological media to isolate gut bacteria. Identification of these isolates was carried out by amplifying and sequencing the 16S rRNA gene and comparing with their closest relatives in GenBank. Cellulolytic, lipolytic and nitrate reductase activities were assayed using Carbonmethyl cellulose (CMC), Rhodamine B and nitrate broth media. Results: The majority of culturable bacteria in the gut of A. dimidiata belonged to two phyla: Firmicutes (62.5%) and Proteobacteria (37.5%). Forty aerobic and eleven anaerobic bacterial strains were isolated and tested for cellulolytic, lipolytic and nitrate reductase activity, and twenty seven and thirty one cellulolytic and lipolytic gut bacteria were identified, respectively, with 19 isolates exhibiting both activities whereas ten facultative anaerobic bacteria isolates were positive for nitrate reductase activity. Interpretation: These bacterial isolates may be good sources for profiling novel isolates and enzymes for industrial use besides identifying new solutions for pest control.