Isolation of Desulfovibrio intestinalis sp nov from the hindgut of the lower termite Mastotermes darwiniensis

A Gram-negative, anaerobic sulfate-reducing bacterium was isolated from hin dgut contents of the lower termite Mastotermes darwiniensis Froggatt (strai n KMS2). Strain KMS2 is motile by a single polar flagellum. The isolate pos sesses desulfoviridin and catalase activity. The G+C content of its DNA is in the range of 54.5-55.5 mol% (strain KMS2). It respires hydrogen and diff erent low molecular weight organic compounds in the presence of sulfate, th iosulfate, and sulfite, and also oxygen. The isolated strain ferments pyruv ate. Fastest growth with a doubling time of 12.5 h was obtained at 37 degre es C and not at 28 degrees C, the temperature at which the termites were gr own. The isolate showed a 16S rDNA sequence homology of 95.9% to Desulfovib rio desulfuricans ATCC 27774 and a DNA-DNA homology of 44.6% to D. desulfur icans Essex 6 (type strain). Based on its biochemical properties and 16S rD NA sequence, the isolate was assigned to a new species named Desulfovibrio intestinalis.