Comamonas granuli sp nov., isolated from granules used in a wastewater treatment plant

Abstract

A Gram-negative, motile, rod-shaped, non-spore-forming bacterial strain, designated as Ko03(T), was isolated from microbial granules, and was characterized, using a polyphasic approach, in order to determine its taxonomic position. The isolate was positive for catalase and oxidase, but negative for gelatinase and beta-galactosidase. Phylogenetic analyses using the 168 rRNA gene sequence showed that the strain formed a monophyletic branch towards the periphery of the evolutionary radiation occupied by the genus Comamonas, its closest neighbors being Comamonas koreensis KCTC 12005(T) (95.9% sequence similarity), Comamonas nitrativorans DSM 13191(T), (95.7%), and Comamonas odontotermitis LMG 23579(T) (95.7%). Strain Ko03T had a genomic DNA G+C content of 68.4 mol % and the predominant respiratory quinone was Q-8. The major fatty acids were C-16:1 omega 7c (44.7%), C-16:0 (28.1%), C-18:1 (16.1%), and C-10:0 3-OH (3.5%). These chemo-taxonomic results supported the affiliation of strain Ko03T to the genus Comamonas. However, low 168 rRNA gene sequence similarity values and distinguishing phenotypic characteristics allowed genotypic and phenotypic differentiation of strain Ko03(T) from recognized Comamonas species. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Ko03T represents a novel species of the genus Comamonas for which the name Comamonas granuli sp. nov. is proposed. The type strain is Ko03(T) (= KCTC 12199(T) = NBRC 101663(T)).