Hydrogen Metabolism by Termite Gut Microbes

Abstract

In Reticulitermes flavipes termites, H₂/CO₂ acetogenesis outcompeted methanogenesis as the main H₂-consuming (i.e., electron sink) reaction of wood fermentation by the hindgut microbiota. Moreover, acetate produced from H₂ + CO₂ supported up to 1/3 of this termite’s respiratory requirement^1,2. To increase our understanding of the nature and nutritional significance of H₂ metabolism by termite gut microbes in general, we have begun extending our studies to taxonomically diverse termites including soil-feeding species. In this paper, we report rates of H₂/CO₂ acetogenesis and methanogenesis in various termite species, as well as the enumeration and isolation of some of the gut bacteria involved in H₂ metabolism.