Denitrobacterium detoxificans gen. nov., sp nov., a ruminal bacterium thatrespires on nitrocompounds

A new group of anaerobic, Gram-positive, high G+C (56-60 mol%) bacteria was isolated from the bovine rumen, Of four strains characterized, all were no nmotile and none produced spores. The isolates did not produce indole or H2 S and did not hydrolyse gelatin. Cells of each strain exhibited similar rod -shaped morphology (0.5-1.0 x 1.0-1.5 mu m) although bulbous ends were some times present. None of the four strains were able to grow via oxidation of a variety of potentially fermentable substrates but rather obtained energy for growth via anaerobic respiration processes, oxidizing hydrogen, formate or lactate for reduction of various oxidized nitrogen compounds. Trimethyl amine oxide and DMSO were also used as electron acceptor. All four strains shared greater than 99% 16S rRNA gene sequence identity. The closest match found between the 16S rRNA gene sequence of all four strains, NPOH1(T), NPO H2, NPOH3 and MAJ1, to sequences available in GenBank was that of Coriobact erium glomerans (86 % sequence similarity), a phenotypically dissimilar ana erobe within the class Actinobacteria, To accommodate these bacteria the cr eation of a new genus and species, Denitrobacterium detoxificans, for place ment within the family Coriobacteriaceae is proposed. The type strain, NPOH 1(T) (ATCC 700546(T)), grew equally well over a narrow range of incubation temperatures tested (32-39 degrees C).