Polaromonas aquatica sp. nov., isolated from tap water.

Two Gram-negative, rod-shaped, non-spore-forming bacteria (CCUG 39402T and CCUG 39797), isolated from different water sources, were investigated in a polyphasic study. The two isolates shared 100% 16S rRNA gene sequence similarity and it was shown that they belonged to the Betaproteobacteria, most closely related to Polaromonas vacuolata (97.8%) and Polaromonas naphthalenivorans (97.8%). A polyamine pattern with 2-hydroxyputrescine and putrescine, as well as ubiquinone Q-8, were in agreement with characteristics of Betaproteobacteria. The presence of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, and major fatty acids C(16:1)omega7c, C(16:0) and C(17:0) cyclo supported the affiliation of the two strains to the genus Polaromonas. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of the two isolates from the two Polaromonas species with validly published names. They therefore represent a novel species, for which the name Polaromonas aquatica sp. nov. is proposed, with the type strain CCUG 39402T (= CIP 108776T).