Mucilaginibacter dorajii sp.nov., isolated from the rhizosphere of Platycodon grandiflorum

Abstract

A Gram-negative, nonmotile and rod-shaped bacterial strain was isolated from the rhizosphere of Platycodon grandiflorum in a study of bacterial diversity, and its taxonomic position was investigated by a genotypic and phenotypic analysis. This isolate, designated as DR-f4, grew at 4-30 °C (optimally at 20-25 °C) and in the presence of 0-1% (w/v) NaCl. It contained MK-7 as the predominant menaquinone. The isolate had activities of catalase, oxidase and β-galactosidase and hydrolyzed aesculin, casein, carboxymethyl-cellulose, starch and l-tyrosine. The major cellular fatty acids were summed feature 3 (C16:1 ω7c and/or iso-C15:0 2OH) and iso-C15:0. The DNA G+C content was 42.6 mol%. This isolate belonged to the genus Mucilaginibacter based on phylogenetic analysis using 16S rRNA gene sequences. The nearest phylogenetic neighbors of strain DR-f4 T were Mucilaginibacter lappiensis ANJL12T and Mucilaginibacter rigui WPCB133T, with 16S rRNA gene sequence similarity levels of 96.9% and 96.4%, respectively. The genotypic and phenotypic evidence suggests that strain DR-f4T should be classified as a novel species, for which the name Mucilaginibacter dorajii sp. nov. is proposed. The type strain for the novel species is DR-f4T (=KACC 14556 T=JCM 16601T).