AbstractsBiology & Animal Science

Termites are among the few insects capable of efficiently digesting cellulose, the major component in wood. This singular ability enables termites to play important ecological roles and makes them major structural pests worldwide. All termite species require the presence of specialized enzymes called cellulases for the digestion of cellulosic materials. In many termite pest species, cellulases are both symbiotic and endogenous in origin. This collaborative cellulase system is central to termite nutrition and survival, and consequently considered a potential target site for novel termite control agents, including cellulase inhibitors. Thus, the overall objective of this research project was to identify novel compounds as potential inhibitors of termite cellulases. Specifically, three prototype cellulase inhibitors were tested against workers of the Eastern subterranean termite, Reticulitermes flavipes, including the disaccharide-based cellobioimidazole (CBI) and fluoro-methyl cellobiose (FMCB) and the monosaccharide-based fluoro-methyl glucose (FMG). These compounds were tested in vitro through cellulase activity assays, as well as in vivo in 24-day bioassays. In addition, this research developed a technique to monitor cellulolytic protozoan populations in termites, as an effort to clarify whether decreases in cellulase activity are the result of protozoan death or enzymatic inhibition. This study provides novel data indicating that the disaccharide-based inhibitor CBI is a strong inhibitor of termite cellulases and caused moderate termite mortality. This research also suggests that quantitative real time -PCR is a viable method to monitor shifts in cellulolytic protozoa populations.