Open AccessBradyrhizobium ripae sp. nov., a nitrogen-fixing symbiont isolated from nodules of wild legumes in Namibia
Author(s) -
Wiebke Bünger,
Jann Lasse Grönemeyer,
Abhijit Sarkar,
Barbara ReinholdHurek
Publication year - 2018
Publication title -
international journal of systematic and evolutionary microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 173
eISSN - 1466-5034
pISSN - 1466-5026
DOI - 10.1099/ijsem.0.002955
Subject(s) - biology , nitrogen fixation , bradyrhizobium , symbiosis , rhizobiaceae , root nodule , botany , microbiology and biotechnology , bacteria , genetics
Root-nodule bacteria were isolated from wild legumes growing in the Kavango region, Namibia. Using a polyphasic approach, four strains belonging to the genus Bradyrhizobium (WR4 T , WR87, T10 and T12) were further characterized to clarify the taxonomic status of this group. On the basis of 16S rRNA gene sequences, the four strains showed highest similarity to Bradyrhizobium elkanii USDA 76 T (99.9 %), Bradyrhizobium pachyrhizi PAC48 T (identical) and to Bradyrhizobiumbrasilense UFLA03-321 T (identical). Multilocus sequence analysis of concatenated glnII-recA-gyrB-dnaK-rpoB sequences and comparison of the intergenic transcribed spacer (ITS) sequences confirmed that the novel group belongs to a distinct lineage of the genus Bradyrhizobium, with <96.7 % (MLSA) and 97.25 % (ITS) nucleotide identity with B. elkanii USDA 76 T . Results from the sequence-based analysis were validated by DNA-DNA hybridization experiments and suggested a novel species. Several phenotypic features including carbon compound utilization and growth characteristics supported the phylogenetic data, thus it is concluded that the strains represent a novel species, for which the name Bradyrhizobium ripae sp. nov. is proposed, with type strain WR4 T [LMG 30283, DSM 105795, NTCCM 0019 (Windhoek)].