The ability of termites to eat wood and break the cellulose down into glucose quickly and efficiently have made studying the insects a point of focus for a number of scientists, including Nobel laureate Steven Chu, now Director of the Lawrence Berkeley Labs, who would like to apply that capability to the large-scale generation of ethanol from cellulosic materials.
Researchers at the University of Florida and Purdue University have identified four cellulase genes—one in the Eastern Subterranean Termite (Reticulitermes flavipes) and three in microscopic symbionts that live inside the termite digestive system. Their study is published in the journal Gene.
This is a significant step forward, especially because we looked at the dominant termite species in the US. But we’re confident we haven’t identified all the genes involved in producing these enzymes.—Michael Scharf, co-author
There may be hundreds of cellulose-digesting enzymes produced by the termites and their symbionts, according to Scharf.
The interaction of multiple genes makes cellulose digestion an efficient process in termites, but scientists want to pin down enzyme combinations that will digest cellulose affordably. UF researchers have applied for funding to support a massive effort to identify all cellulose-digesting genes in the eastern subterranean termite and its common symbionts.
Diversa, Caltech, Instituto Nacional de Biodiversidad and the Joint Genome Institute are also working on identifying cellulase enzymes in termite guts.
One potential approach to applying the research would be transferring specific cellulase-expressing genes into bacteria, optimizing them and then culturing the leading bacteria to produce large quantities of enzymes to make ethanol from wood scraps and other fibrous materials.
“Correlation of cellulase gene expression and cellulolytic activity throughout the gut of the termite Reticulitermes flavipes”; Xuguo Zhou, Joseph A. Smith, Faith M. Oi, Philip G. Koehler, Gary W. Bennett and Michael E. Scharf; Gene, in press, available online 26 January 2007