Sunday, July 24, 2011
Grand Ballroom, 5th fl (Sheraton New Orleans)
Termites are among the most economically important pests of wooden structures, but despite their destructiveness, termites have an extremely important role in the carbon, nitrogen, and sulfur cycles in nature. All termites are dependent upon an intricate symbiotic relationship with prokaryotes, and in some instances, protists (protozoans) and/or fungi. With the assistance of endosymbionts, termites are responsible for the conversion of biopolymers to simple carbon substrates. Furthermore, due to dietary limitations on the intake of nitrogenous compounds (wood being limited in nitrogen), termites rely on microbial endosymbionts for fixing and recycling nitrogen. As a result, we hypothesize that termite-associated bacteria are a potentially novel source of biocatalysts for the degradation of explosives, which are typically nitrogen rich. The creation of in situ enrichments for bacterial endosymbionts was accomplished by cultivating termites on sterile, unbleached filter paper dosed with various historic or more recently developed explosives compounds, i.e. RDX, TNT, NTO. The microbial communities in control and explosives-fed termites were compared and contrasted using denaturing gradient gel electrophoresis as a molecular fingerprinting technique followed by DNA sequencing identification. Termites were capable of eating substrate spiked with up to 100 ppm of each explosive for 20 days before sacrifice. Community composition between treatment groups and controls exhibited numerous differences. Subsequently, tailored anaerobic isolation of enriched termite gut bacteria upon explosives is expected to yield organisms with unique abilities to degrade nitrogenous compounds relevant to the degradation of nitrogen rich energetic material and potentially novel enzymes and pathways.