Bacterial communities in worker versus

Soldier and worker castes of lower wood-feeding termites, Reticulitermes flavipes, differ in morphology and diet, and may therefore play host to distinct bacterial communities. While many studies have attempted to characterize the gut microbiota in lower termites, to date no study exists which explores the differences in bacterial communities in these two lower termite castes . In this study TRFLP and clonal analyses of the 16S rRNA gene were used to compare bacterial community composition in the guts of soldier versus worker termites. Clone library analysis found a significant difference in the two communities, although TRFLP data was inconclusive. Enrichments for N2 fixing microorganisms in each caste were also carried out, yielding growth in higher dilutions for workers versus soldiers although all growth consisted of Lactococcus monocultures. Community analysis based on clone libraries highlighted three candidate taxa for future comparisons of the two bacterial communities. Introduction: This study focused on the differences in bacterial communities residing in the guts of worker versus soldier castes of the lower wood-feeding termite, Reticulitermes flavipes. Termite soldiers are unable to feed themselves due to their enlarged mandibles, and must therefore rely on the worker caste to provide them with regurgitated droplets of partially digested food. There has been speculation that this difference in diet between the two castes may result in a difference in gut microbiota of lower termites, but no literature exists which explores this theory empirically. TRFLP and clone library analysis of the 16S rRNA gene were used to compare the communities of these castes. The high lignocellulose diet has a C:N ratio of 1000:1, as compared to the 10:1 ratio of termite biomass. Thus, R. flavipes are strongly limited by N and rely heavily on their gut microbiota as a sole source of N2 fixation. It is possible, however, that the regurgitate fed