In this study, we attempted to identify bacteria that produce major lignocellulolytic enzymes in the hindgut of higher termites, with the aid of production of monoclonal antibodies against proteins on the surface of bacterial community associated with wood particles using the wood-feeding termite, Nasutitermes takasagoensis. We successfully obtained 15 different monoclonal antibodies, while the screening against the predominantly expressed xylanase in the wood fiber-associated bacterial community identified one monoclonal antibody cross-reacting the xylanase. Indirect fluorescence microscopy using epifluorescence and confocal laser-scanning microscopes indicated that this antibody recognized the entire cell surface of some helical bacteria associated with the wood-fibers in the hindgut. These antibodies are among valuable property for future studies on bacterial symbiosis in termites.

We investigated on the intraspecific variation in fore-stomach microbial communities of proboscis monkeys inhabiting mangrove and riverine forests, Sabah, Borneo, Malaysia. We found that proboscis monkeys have a similar microbe community to that in ruminants including Ruminococcus sp., Prevotella sp., Oscillospira sp. and Selenomonas sp. In addition, the diversity of microbe community was much higher in the proboscis monkeys living in a riverine forest compared to those in a mangrove forest, suggesting that the differences of their food habits between riverine and mangrove forests strongly influence their microbe community.

The present study explored metabolic factors that involved in invention of efficient cellulolytic systems during evolution from wood roaches to termites. In evolution of wood roaches to lower termites, we found some overlaps of metabolic networks between endo- and intestinal symbioses, which had led to relaxed selection of some genes in endosymbionts and increased in dependence of the host insects in intestinal symbionts. In lower termites, we analyzed a genome sequence of a Japanese subterranean lower termite. Endogenous cellulase genes were duplicated in the genome, while a few of them appeared to differentiate their functions. Furthermore, we analyzed transcripts of the so-called “the mixed segment" in the gut of a higher termite, which expressed a variety of transporter genes. Among them, V-ATPases and NHE transporters were assumed to be involved in the gut alkalization, which may contribute to solubilize lignin to facilitate cellulose degradation by the intestinal bacteria.