Rhizobium kunmingense sp. nov., isolated from rhizosphere soil of Camptotheca acuminata Decne

Abstract

Strain LXD30^T was isolated from rhizosphere soil of a plant of the species Camptotheca acuminata Decne which is native to warm, humid stream banks in southern China. Analysis of the 16S rRNA gene sequence revealed that the Gram-negative, rod-shaped bacterium fell within the realm of the genus Rhizobium and was most closely related to Rhizobium huautlense SO2^T (96.4% sequence similarity) and Rhizobium cellulosilyticum LMG 23642^T (96.4%). The isolate grew optimally at pH7.0 and 25-28ºC in the presence of 0-1% (w/v) NaCl. Major fatty acids were C16:0 (17.5%) and summed feature 7 (C18:1ω7c/ω9t/ω12t, 58.3%). Unequivocally low 16S rRNA (<97%), recA (<92%) and atpD (<90%) gene sequence similarities to all existing species of the genus and phenotypic characteristics all suggested that strain LXD30^T (=KCTC 22609^T=CGMCC 1.8903^T) represents a novel Rhizobium species, for which the name Rhizobium kunmingense sp. nov. is proposed.