Acidovorax caeni sp. nov., a denitrifying species with genetically diverse isolates from activated sludge

Laboratory of Microbiology, Department of Biochemistry, Physiology and Microbiology, Ghent University, K. L. Ledeganckstraat 35, B-9000 Gent, Belgium Correspondence Kim Heylen Kim.Heylen{at}UGent.be Four Gram-negative, rod-shaped, non-spore-forming, denitrifying isolates were obtained from the activated sludge of an aerobic–anaerobic wastewater treatment plant in Belgium. Analysis of repetitive sequence-based PCR showed that the four isolates were genetically different from each other. Results of 16S rRNA gene sequence analysis and DNA–DNA hybridization experiments indicated that these four isolates were affiliated to the genus Acidovorax and could be differentiated from all recognized species of the genus. Analysis of whole-cell proteins and results of physiological and biochemical tests allowed differentiation of the new isolates from their closest phylogenetic neighbours. These new isolates therefore represent a novel species of the genus Acidovorax , for which the name Acidovorax caeni sp. nov. is proposed. The type strain is R-24608 T (=LMG 24103 T =DSM 19327 T ). The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain R-24608 T is AM084006 . A figure showing the grouping of normalized digitized SDS-PAGE patterns for members of the genus Acidovorax is available as supplementary material with the online version of this paper.