ABSTRACTPreviously we reported the cultivation of novel verrucomicrobia, including strain TAV2 (93% 16S rRNA gene identity to its nearest cultivated representative,Opitutus terreaePB90-1) from the gut of the termiteReticulitermes flavipes. To gain better insight into theVerrucomicrobiaas a whole and understand the role of verrucomicrobia within the termite gut ecosystem, we analyzed a draft genome and undertook a physiological characterization of TAV2. Strain TAV2 is an autochthonous member of theR. flavipesgut microbiota and groups phylogenetically among diverseVerrucomicrobiafromR. flavipesand other termites that are represented by 16S rRNA gene sequences alone. TAV2 is a microaerophile, possessing a high-affinitycbb3-type terminal oxidase-encoding gene and exhibiting an optimum growth rate between 2 and 8% (vol/vol) oxygen. It has the genetic potential to degrade cellulose, an important function within termite guts, but itsin vitrosubstrate utilization spectrum was limited to starch and a few mono- and disaccharides. Growth occurred on nitrogen-free medium, and genomic screening revealed genes for dinitrogenases, heretofore detected in only a few members of theVerrucomicrobia. This represents the first (i) characterization of a verrucomicrobial species from the termite gut, (ii) report ofnifandanfgenes in a nonacidophilic verrucomicrobial species, and (iii) description of a microaerophilic genotype and phenotype in this phylum of bacteria. The genetic and physiological distinctiveness of TAV2 supports its recognition as the type strain of a new genus and species, for which the nameDiplosphaera colitermitumgen. nov., sp. nov., is proposed.