Breznak 9709000 Roughly 2000 species of termites degrade 1 billion tons annually of lignocellulosic plant material and residues derived from it (e.g. humus) and in doing so derive nutrition from some of earth's most abundant, but refractory and nitrogen-poor food resources. To accomplish this feat, they have evolved into spectacular symbioses with gut microorganisms representing all known domains of life on Earth -- Bacteria, methane-producing Archaea, and Eukarya (protozoa). Such microbes are important in: (i) nitrogen economy (via N2-fixation and excretory N-recycling); (ii) production of acetate (a major carbon and energy source for termites) from H2 + CO2; and (iii)production of digestive enzymes. Nevertheless, a lingering source of frustration has been an inability to culture (and thereby better understand) some of the major members of the termite gut community, ea. spirochetes. However, molecular biological tools now afford a means to probe the nature, number, physiological role(s), and phylogenetic diversity of termite gut microbes without the absolute requirement for cultivation. Accordingly, research in this project will integrate molecular biological approaches with biochemical and physiological studies to increase our understanding of termite gut spirochetes, as well as a variety of other microbes relevant to termite nutrition and vitality. It is expected that this research will continue to reveal termites as a rich reservoir of novel (and largely untapped) microbial diversity and a fruitful system for discovering new principles of microbial interactions.
