Phenylobacterium falsum sp nov., an Alphaproteobacterium isolated from a nonsaline alkaline groundwater, and emended description of the genus Phenylobacterium

A Gram-negative bacterium designated AC-49(T) Was isolated from an alkaline groundwater with a pH 11.4. This organism formed rod-shaped cells, was strictly aerobic, catalase and oxidase positive, with an optimum growth temperature of 35 degrees C and an optimum pH value of 8.0. Strain AC-49(T) assimilated primarily amino acids and some Krebs cycle metabolites, did not use sugars for growth. The organism did not grow on L-phenylalanine or antipyrin. The G+C content of DNA was 66.9mol%. The phylogenetic analyses based on the 16S rRNA sequencing showed that the closest relatives of strain AC-49(T) were Phenylobacterium lituiforme and Phenylobacterium innnobile, indicating that the organism is a member of the order Caulobacterales of the Alphaproteobacteria. Based on the phylogenetic analyses and distinct phenotypic characteristics, we are of the opinion that strain AC-49(T), represents a novel species of the genus Phenylobacterium for which we propose the name Phenylobacterium falsum sp. nov. (c) 2005 Elsevier GmbH. All rights reserved.