Two hundred and thirteen isolates of soybean bradyrhizobia indigenous to six field sites in Japan were characterized using hybridization probes RSK, RSL, nifDK and hupSL from Bradyrhizobium japonicum and indole-3-acetic acid production to clarify diversity and endemism of their population structures. Significant diversities and site-dependent variations were observed in terms of Bradyrhizobium ...

Extracts of Bradyrhizobium japonicum were fractionated on Sepharose columns covalently derivatized with lactose. Elution of the material that was specifically bound to the affinity column with lactose yielded a protein of Mr approximately 38,000. Isoelectric focusing of this sample yielded two spots with pI values of 6.4 and 6.8. This protein specifically bound to galactose-containing glycoconj...

The recent sequence analysis of the photosynthetic and plant-symbiotic Bradyrhizobium sp. strain BTAi1 revealed the unexpected presence of a pucBA operon encoding the apoproteins of peripheral light-harvesting (LH) complexes. This pucBA operon is found close to a bacteriophytochrome gene (BphP3(B BTAi1)) and a two-component transcriptional regulator gene (TF(BTAi1) gene). In this study, we show...

The ecological examination of members of the family Rhizobiaceae has been hampered by the lack of a selective medium for isolation of root nodule bacteria from soil. A novel non-antibiotic-containing medium has been developed which allows selective isolation of Bradyrhizobium japonicum and B. elkanii strains from soil and inoculants. The medium, BJSM, is based on the resistance of B.japonicum a...

Bradyrhizobium embrapense CNPSo 2833T is a nitrogen-fixing symbiont of the legume pasture Desmodium. Its draft genome contains 8,267,832bp and 7876 CDSs. The symbiotic island includes nodulation and nitrogen fixation genes resembling the operon organization of B. japonicum. Several CDSs related to secretion proteins and stress tolerance were also identified.

Two oxygen-responsive regulatory systems controlling numerous symbiotic genes in Bradyrhizobium japonicum were assayed in free-living cultures for their capacity to activate target genes under different oxygen conditions. NifA- and FixLJ-controlled target genes showed disparate relative expression patterns. Induction of NifA-dependent genes was observed only at oxygen concentrations below 2% in...