Spatial distribution of bacterial phylotypes in the gut of the termite Reticulitermes speratus and the bacterial community colonizing the gut epithelium

The bacterial community colonizing the gut wall of the termite Reticulitermes speratus was characterized without cultivation. Analysis of 16S rRNA genes after fractionation of the gut revealed that the bacterial composition on the gut wall was diverse and significantly different from that able to move unconfined in the gut fluid or physically associated with the gut protists. Actinobacteria, Firmicutes and Bacteroidetes were dominant on the gut wall, but Spirochaetes and the Termite group 1 phylum, abundant in the gut lumen, were relatively rare. A sequence-specific probe enabled the in situ detection of a rod-shaped Actinobacteria member, abundantly colonizing the gut paunch epithelium.