Mesorhizobium shangrilense sp. nov., isolated from root nodules of Caragana species

1 State Key Laboratories for Agro biotechnology/College of Biological Sciences, China Agricultural University, Beijing 100193, PR China 2 Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, México D. F. 11340, Mexico 3 Agricultural Cultural Collection of China, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China 4 College of Life Science, Capital Normal University, Beijing 100037, PR China Correspondence Wen Feng Chen chenwf{at}cau.edu.cn Five strains of bacteria isolated from nodules of Caragana bicolor and Caragana erinacea in Yunnan Province of China were classified within the genus Mesorhizobium in the class Alphaproteobacteria . The highest degree of 16S rRNA gene sequence similarity was determined to be to Mesorhizobium loti LMG 6125 T (99.7 %) and Mesorhizobium ciceri UPM-Ca7 T (99.7 %). Polyphasic taxonomic methods including SDS-PAGE of whole-cell soluble proteins, comparative housekeeping sequence analysis of atpD , glnII and recA , fatty acid profiles and a series of phenotypic and physiological tests allowed us to cluster the five strains into a coherent group while differentiating them from all previously established Mesorhizobium species. The DNA–DNA relatedness between the representative strain CCBAU 65327 T and the type strains of M. loti and M. ciceri was 26.5 and 23.4 %, respectively, clearly indicating that strain CCBAU 65327 T represents a novel species for which we propose the name Mesorhizobium shangrilense sp. nov. Strain CCBAU 65327 T (=LMG 24762 T =HAMBI 3050 T ) is designated as the type strain, and could nodulate Caragana microphylla , Caragana intermedia , Glycyrrhiza uralensis, Astragalus adsurgens , Vigna unguiculata , Vigna radiata and Phaseolus vulgaris in cross-nodulation tests. Abbreviations: MP, maximum-parsimony; NJ, neighbour-joining The GenBank/EMBL/DDBJ accession numbers for the partial 16S rRNA, atpD , recA , glnII , nodC and nifH gene sequences of strain CCBAU 65327 T are EU074203 , EU672471 , EU672501 , EU672486 , EU687487 and EU877532 , respectively. Fatty acid profiles, sequence similarities, nodC and nifH gene phylogenetic trees and a phenogram derived from UPGMA/ S SM analysis and SDS-PAGE analysis of whole-cell soluble proteins of strains from Mesorhizobium shangrilense sp. nov. and related species are available as supplementary material with the online version of this paper.