Description of Pelomonas aquatica sp. nov. and Pelomonas puraquae sp. nov., isolated from industrial and haemodialysis water

Abstract

Three Gram-negative, rod-shaped, non-spore-forming bacteria (strains CCUG 52769T, CCUG 52770 and CCUG 52771) isolated from haemodialysis water were characterized taxonomically, together with five strains isolated from industrial waters (CCUG 52428, CCUG 52507, CCUG 52575T, CCUG 52590 and CCUG 52631). Phylogenetic analysis based on 16S rRNA gene sequences indicated that these isolates belonged to the classBetaproteobacteriaand were related to the genusPelomonas, with 16S rRNA gene sequence similarities higher than 99 % with the only species of the genus,Pelomonas saccharophilaand toPseudomonassp. DSM 2583. The type strains ofMitsuaria chitosanitabidaandRoseateles depolymeranswere their closest neighbours (97.9 and 97.3 % 16S rRNA gene sequence similarity, respectively). Phylogenetic analysis was also performed for the internally transcribed spacer region and for three genes [hoxG(hydrogenase),cbbL/cbbM(Rubisco) andnifH(nitrogenase)] relevant for the metabolism of the genusPelomonas. DNA–DNA hybridization, major fatty acid composition and phenotypical analyses were carried out, which included the type strain ofPelomonas saccharophilaobtained from different culture collections (ATCC 15946T, CCUG 32988T, DSM 654T, IAM 14368Tand LMG 2256T), as well asM. chitosanitabidaIAM 14711TandR. depolymeransCCUG 52219T. Results of DNA–DNA hybridization, physiological and biochemical tests supported the conclusion that strains CCUG 52769, CCUG 52770 and CCUG 52771 represent a homogeneous phylogenetic and genomic group, including strain DSM 2583, clearly differentiated from the industrial water isolates and from thePelomonas saccharophilatype strain. On the basis of phenotypic and genotypic characteristics, these strains belong to two novel species within the genusPelomonas, for which the namesPelomonas puraquaesp. nov. andPelomonas aquaticasp. nov. are proposed. The type strains ofPelomonas puraquaesp. nov. andPelomonas aquaticasp. nov. are CCUG 52769T(=CECT 7234T) and CCUG 52575T(=CECT 7233T), respectively.