Latest Research on Bradyrhizobium: Dec – 2019

Latest Research on Bradyrhizobium: Dec – 2019

Latest Research on Bradyrhizobium: Dec – 2019

Genetic diversity in Bradyrhizobium japonicum Jordan 1982 and a proposal for Bradyrhizobium elkanii sp.nov.

Fourteen randomly selected clones from cosmid libraries of Bradyrhizobium were used as hybridization probes in Southern blot analysis. Seven of the probes used were from strain USDA 83, a gaggle II strain, and therefore the other seven were from strain I-110, a gaggle Ia strain. The 30 strains examined included 9 strains of Rj4-incompatible soybean bradyrhizobia. Considerable polynucleotide sequence dissimilarity between DNA homology groups was evidenced by striking differences within the number of hybridizing bands, except where the probe carried repetitive DNA. Predictable, simple fragment length polymorphism differences were observed only within DNA homology groups. The previous description that 8 of 9 Rj4-incompatible strains belonged to DNA homology group II was verified. The new data, along side many previously documented differences, make it clear that the DNA homology group II organisms should be classified as a replacement species, that the name Bradyrhizobium elkanii is proposed, and strain USDA 76 is designated the sort strain. The ATCC number for the sort strain is 49852. Key words: DNA:DNA hybridization, soybean, nodulation, bacteria, symbiosis, organic process, host compatibility. [1]

Complete Genomic Sequence of Nitrogen-fixing Symbiotic Bacterium Bradyrhizobium japonicum USDA110

The complete nucleotide sequence of the genome of a symbiotic bacterium Bradyrhizobium japonicum USDA110 decided. The genome of B. japonicum was one circular chromosome 9,105,828 bp long with a mean GC content of 64.1%. No plasmid was detected. The chromosome comprises 8317 potential protein-coding genes, one set of rRNA genes and 50 tRNA genes. Fifty-two percent of the potential protein genes showed sequence similarity to genes of known function and 30% to hypothetical genes. The remaining 18% had no apparent similarity to reported genes. Thirty-four percent of the B. japonicum genes showed significant sequence similarity to those of both Mesorhizobium loti and Sinorhizobium meliloti , while 23% were unique to the present species. [2]

Fatty Acids, Antibiotic Resistance, and Deoxyribonucleic Acid Homology Groups of Bradyrhizobium japonicum

The carboxylic acid compositions and multiple antibiotic resistance patterns of 32 strains of Bradyrhizobium japonicum correlated with two major desoxyribonucleic acid homology groups. In group I, the carboxylic acid composition was 1.3% 16:1 cis9 acid, 3.6% 16:1C acid, 8.8% 16:0 acid, 1.2% 19:0 cyclopropane acid, and 81.2% 18:1 acid. Group II contained 0.5% 16:1C acid, 11.1% 16:0 acid, 0.8% 17:0 cyclopropane acid, 24.7% 19:0 cyclopropane acid, and 62.3% 18:1 acid. Group I strains were vulnerable to rifampin (500 μg/ml), tetracycline (100 μg/ml), streptomycin (100 μ/ml), chloramphenicol (500 μg/ml), erythromycin (250 μg/ml), carbenicillin (500 μg/ml), and NegGram (50 μg/ml), whereas group II strains were immune to these antibiotics. Both groups were immune to trimethoprim (50 μg/ml) and vancomycin (100 μg/ml). [3]

Novel European free-living, non-diazotrophic Bradyrhizobium isolates from contrasting soils that lack nodulation and nitrogen fixation genes – a genome comparison

The slow-growing genus Bradyrhizobium is biologically important in soils, with different representatives found to perform a variety of biochemical functions including photosynthesis, induction of root nodules and symbiotic organic process and denitrification. Consequently, the role of the genus in soil ecology and biogeochemical transformations is of agricultural and environmental significance. Some isolates of Bradyrhizobium are shown to be non-symbiotic and don’t possess the power to make nodules. Here we present the genome and gene annotations of two such free-living Bradyrhizobium isolates, named G22 and BF49, from soils with differing long-term management regimes (grassland and bare fallow respectively) additionally to carbon metabolism analysis. [4]

Nutritional Status of Cowpea Plants Inoculated with Bradyrhizobium and Azospirillum brasilense in Associated with Phosphate Fertilization in Soil Amazonian

Biological organic process (BNF) plays a crucial role in cowpea cultivation. Thus, this study aimed to guage the consequences of inoculation and co-inoculation of rhizobacteria related to phosphate fertilization on biometric parameters and absorption and use of nutrients by different cowpea genotypes. The experimental design was randomized blocks during a 4x3x2 factorial scheme, like four rates of phosphorus (0, 80, 120 and 160 kg ha-1 of P2O5), absence, inoculation and co-inoculation with rhizobacteria; two cowpea genotypes (White and Butter), with four replicates. The results revealed variability between the cowpea genotypes with reference to efficiency and response to phosphorus application. [5]

Reference

[1] Kuykendall, L.D., Saxena, B., Devine, T.E. and Udell, S.E., 1992. Genetic diversity in Bradyrhizobium japonicum Jordan 1982 and a proposal for Bradyrhizobium elkanii sp. nov. Canadian Journal of Microbiology, 38(6), (Web Link)

[2] Kaneko, T., Nakamura, Y., Sato, S., Minamisawa, K., Uchiumi, T., Sasamoto, S., Watanabe, A., Idesawa, K., Iriguchi, M., Kawashima, K. and Kohara, M., 2002. Complete genomic sequence of nitrogen-fixing symbiotic bacterium Bradyrhizobium japonicum USDA110. DNA research, 9(6), (Web Link)

[3] Kuykendall, L.D., Roy, M.A., O’neill, J.J. and Devine, T.E., 1988. Fatty acids, antibiotic resistance, and deoxyribonucleic acid homology groups of Bradyrhizobium japonicum. International Journal of Systematic and Evolutionary Microbiology, 38(4), (Web Link)

[4] Novel European free-living, non-diazotrophic Bradyrhizobium isolates from contrasting soils that lack nodulation and nitrogen fixation genes – a genome comparison
Frances Patricia Jones, Ian M. Clark, Robert King, Liz J. Shaw, Martin J. Woodward & Penny R. Hirsch
Scientific Reports volume 6, (Web Link)

[5] Oliveira Araújo, Érica de, Mauad, M., César Tadeu, H., Lima Filho, H. A. de, Figueira da Silva, J. A. and Avelino Cardoso, J. (2018) “Nutritional Status of Cowpea Plants Inoculated with Bradyrhizobium and Azospirillum brasilense in Associated with Phosphate Fertilization in Soil Amazonian”, Journal of Experimental Agriculture International, 23(5), (Web Link)

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