Polaromonas aquatica sp. nov., isolated from tap water

Abstract

Two Gram-negative, rod-shaped, non-spore-forming bacteria (CCUG 39402^T 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 ω7c, 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 39402^T (=CIP 108776^T).