Anaerovorax odorimutans gen. nov., sp. nov., a putrescine-fermenting, strictly anaerobic bacterium

The strictly anaerobic, Gram-positive, non-spore-forming bacterium strain NorPut1T ferments putrescine to acetate, butyrate, molecular hydrogen and ammonia. It also utilizes 4-aminobutyrate and 4-hydroxybutyrate as growth substrates. Comparative 16S rDNA sequence analysis confirmed a phylogenetic affiliation of this strain to the phylum of Gram-positive bacteria with low DNA GMC content. Together with its closest relative, Clostridium aminobutyricum (DSM 2634), and several Eubacterium species, strain NorPut1T represents a well-defined monophyletic group. Moderate overall 16S rRNA sequence similarities (< 91%) were found for the NorPut1T/ Clostridium aminobutyricum pair and several Eubacterium species. The type species, Eubacterium limosum, is not a member of the group and, together with Eubacterium barkeri and Pseudoramibacter alactolyticus, represents a distant phylogentic cluster. Therefore, a new genus, Anaerovorax, is proposed as harbouring strain NorPut1T (=DSM 5092T), which is described as a new species, i.e. Anaerovorax odorimutans