Rhizobium azibense sp. nov., a nitrogen fixing bacterium isolated from root-nodules of Phaseolus vulgaris.
Three microbial strains isolated from common beans, 23C2T (Tunisia), Gr42 (Spain) and IE4868 (Mexico), which have been identified previously as representing a genomic group closely related to Rhizobium gallicum, are further studied here. Their 16S rRNA genes showed 98.5-99% similarity with Rhizobium loessense CCBAU 7190BT, R. gallicum R602spT, Rhizobium mongolense USDA 1844T and Rhizobium yanglingense CCBAU 71623T. Phylogenetic analysis based on recA, atpD, dnaK and thrC sequences showed that the novel strains were closely related and could be distinguished from the four type strains of the closely related species. Strains 23C2T, Gr42 and IE4868 could be also differentiated from their closest phylogenetic neighbours by their phenotypic and physiological properties and their fatty acid contents. All three strains harboured symbiotic genes specific to biovar gallicum. Levels of DNA-DNA relatedness between strain 23C2T and the type strains of R. loessense, R. mongolense, R. gallicum and R. yanglingense ranged from 58.1 to 61.5%. The DNA G+C content of the genomic DNA of strain 23C2T was 59.52%. On the basis of these data, strains 23C2T, Gr42 and IE4868 were considered to represent a novel species of the genus Rhizobium for which the name Rhizobium azibense is proposed. Strain 23C2T (=CCBAU 101087T=HAMBI3541T) was designated as the type strain.
Laboratory of Legumes, Centre of Biotechnology of Borj-Cédria, BP 901, Hammam-lif 2050, Tunisia.
Bacem
B
Mnasri
State Key Lab for Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
Tian Yan
TY
Liu
Laboratory of Legumes, Centre of Biotechnology of Borj-Cédria, BP 901, Hammam-lif 2050, Tunisia.
Sabrine
S
Saidi
State Key Lab for Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
Wen Feng
WF
Chen
State Key Lab for Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
Wen Xin
WX
Chen
Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100080, PR China.
Xiao Xia
XX
Zhang
Laboratory of Legumes, Centre of Biotechnology of Borj-Cédria, BP 901, Hammam-lif 2050, Tunisia.
Ridha
R
Mhamdi
D015373:Bacterial Typing Techniques; D001482:Base Composition; D004269:DNA, Bacterial / Q000235:genetics; D005227:Fatty Acids / Q000737:chemistry; D005798:Genes, Bacterial; D008800:Mexico; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation; D009693:Nucleic Acid Hybridization; D027805:Phaseolus / Q000382:microbiology*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012231:Rhizobium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D053204:Root Nodules, Plant / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013030:Spain; D014416:Tunisia
D004269:DNA, Bacterial; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S