Aerobic and facultative anaerobic bacteria from gut of red palm weevil (Rhynchophorus ferrugineus)

Abstract

Red palm weevil (RPW), Rhynchophorus ferrugineus Oliver is one of the insects that attack date palm trees directly and cause its death. This infection poses serious economical consequences in Saudi
Arabia and other gulf countries. RPW assimilates the components of palm tree tissues. Significant amount of microbiota in the gut of RPW may contribute to success of its pathogenesis. This study
explored the nature of microbiota in RPW by culture-dependent and molecular-based techniques using PCR and sequencing analysis. Larvae of RPW were fed on an artificial diet and were fixed before
opening its gut for microbial cultivation on enrichment media. Pure cultures were obtained after incubating the plates at different atmospheric conditions (aerobic, and strictly anaerobic). The majority
of isolated microbiota observed were aerobes and facultative anaerobes (Bacillus sp., Salmonella sp., Enterococcus sp., and Xanthomonas sp.). These qualitative differences of bacteria, suggest the presence of a complex ecosystem in the gut of RPW. Subsequently, bacterial DNAs were extracted from pure cultures for definitive molecular identifications. Hot start-touchdown PCR was performed to
amplify regions within 16S rDNA. Amplicons were cloned into the TOPO-TA vector for sequencing. The data reveal to some extent that aerobic and facultative anaerobic bacteria are more distributed in the gut of RPW.