Differential Gut Bacteria in Phosphine Resistant and Susceptible Population of Tribolium castaneum (Herbst) and their Biochemical and Molecular Characterization

Gut bacteria community associated with insects are crucial to understand their function in the physiology of the host. The hypothesis of the present study was that gut microbiota in phosphine resistant population inhabits phosphine degrading bacteria. The study demonstrated the differential gut bacteria in phosphine-resistant and susceptible populations in Tribolium castaneum. Phosphine bioassay of different populations of T. castaneum revealed that Jagatsinghpur (Odisha, India) population had the highest LC50 value (1.104 mg/l). Further, gut bacteria were isolated and characterized through biochemical and molecular techniques. Among nine isolates of bacteria from resistant and susceptible populations, six isolates belonged to gram positive bacteria and three belonged to gram-negative. The 16S rRNA gene sequences displayed 96 to 100 per cent homology to other 16S rRNA gene of strains within the National Centre for Biotechnological information (NCBI), Genbank. Among different bacteria strains, two, Bacillus subtilis and Staphylococcus saprophyticus were reported from resistant populations. Other species belonged to Staphylococcus sp., Enterobacter sp., Lysinibacillus fusiformis, Klebsiella pneumonia (all four from resistant populations) and Achromobacter sp (from a susceptible population). Present study provides a basis for elucidating the role of the gut bacteria in the phosphine resistance and design novel strategies for the management of T. castaneum.