Description of Pseudaminobacter gen. nov. with two new species, Pseudaminobacter salicylatoxidans sp. nov. and Pseudaminobacter defluvii sp. nov.

An aerobic bacterium, strain BN12(T), which degrades substituted naphthalen esulfonates and substituted salicylates was isolated from a 6-aminonaphthal ene-2-sulfonate-degrading microbial consortium originating from the River E lbe, Germany, Chemotaxonomic investigations of quinones, polyamines and pol ar lipids allowed allocation of this strain to the alpha-subclass of the Pr oteobacteria and revealed similarity to species of the genera Aminobacter, Chelatobacter and Mesorhirobium. This was confirmed by typing with 16S rRNA -targeted oligonucleotide probes and 16S rDNA sequencing and phylogenetic a nalysis, indicating that BN12(T) clusters most closely with a strain 'Thiob acillus' THI 051(T) and with the above genera but comprising a separate bra nch. DNA-DNA hybridizations demonstrated that strain BN12(T) is different f rom all species of Aminobacter currently described and recognized. The fatt y acid patterns, substrate utilization profile and biochemical characterist ics displayed no obvious similarity to the characteristics of Aminobacter a nd Chelatobacter species. 'Thiobacillus' THI 051(T), however, revealed phen otypic similarities to BN12(T). Furthermore, 16S rRNA sequences of Chelatob acter heintzii showed a high similarity to the 16S rRNA sequences of all cu rrently recognized Aminobacter species. On the basis of these and previousl y published results, the new genus Pseudaminobacter is proposed, harbouring the two new species Pseudaminobacter salicylatoxidans sp, nov, and Pseudam inobacter defluvii sp. nov. The type strains are BN12(T) (= DSM 6986(T)) an d THI 051(T) (= IFO 14570(T)), respectively.