• Applied Biological Chemistry
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• v.30 no.2
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• pp.163-168
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• 1987

A method, based upon the separation of cellular proteins by one-and two-dimensional electrophoresis was used for distinguishing butween Bradyrhizobium japonicum strains and Rhizobium fredii strains. Significant differences in protein pattern of one-dimensional SDS-PAGE vs-ere observed between Rhizobium fredii strains and Bradyrhizobium japonicum strains. The differences in six distinct main lands were observed among total 52 kinds of protein bands. Furthermore, the distribution of proteins in two groups by two-dimensional polyacrylamide gel electrophoresis was very different. The majority of visible proteins of Rhizobium fredii were acidic, whereas those of Bradyrhizobium japonicum were basic. In addition, amino acid composition was analyzed to detect the differences between two groups. No significant differences in amino acid composition were observed between Bradyrhizobium japonicum strains and Rhizobium fredii strains. The results indicate that one-and two-dimensional polyacrylamide gel electrophoresis were useful for identifying rhizobia isolates. One-dimensional SDS-PAGE of rhizobia proteins provided a rapid method for screening a large number of isolates, whereas two-dimensional electrophoresis was more of resolution and easiness for analyzing protein spots.

• Korean Journal Plant Pathology
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• v.12 no.3
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• pp.351-357
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• 1996

콩으로부터 분리한 140균주의 근류균은 25균주(17.9%)가 Rhizobium fredii로 115 균주(82.1%)가 Brady-rhizobium japonicum으로 동정되었다. R. fredii에 속하는 분리 균주의 생존 pH 범위는 4..5∼9.0이었고 B. japonicum의 생육 pH 범위는 5.5∼8.0로 비교적 좁게 나타났다. B. japonicum에 속하는 98균주 중에서는 53균주(54%)가 IAA를 생산하지 않는 GT I group으로, 45균주(46%)는 IAA를 생산하는 GT II group으로 명확하게 구분되었으며, 항생물질에 대한 내성 유무에 의해 10개의 group으로 구분되었다.

• Korean Journal of Microbiology
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• v.26 no.4
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• pp.312-317
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• 1988

The genes for ribosomal RNA in Rhizobium meliloti and Bradyrhizobium japonicum were analyzed by southern hybridization of BamHI, EcoRI, HindIII digested chromosomal DNA with purified 5' $^{32}P$-labeled 16S and 23S rRNA. The big differences in the hybridization pattern of both rhizobia were found. The comparative results were discussed in relation to the copy number and conservativity of restriction sites in the rRNA genes of both rhizobia.

• Korean Journal of Microbiology
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• v.26 no.4
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• pp.305-311
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• 1988

The spectinomycin resistant strain of slow growing R. japonicum R-168 was selected to be participated in conjugation with E. coli WA803/pGS9. Tn5 was introduced from suicide vector pGS9 into R. japonicum R-168 $spr^{r}$ chromosome at the frequency of $1.0\times 10^{-5}-5.0\times 10^{-7}$ and the transconjugante were selected on the yeast extract-mannitol plate containing kanamycin ($50{\mu}$g/ml) and spectinomycin ($100{\mu}$g/ml) after 8-9 days incubation. All transconjugants we tested were found to contain Tn 5 DNA on their genome, which was confirmed by Southern hybridization experiments. R. japonicum RNa75, which had been selected through plant test, was found to be defective in symbiotic nitrogen fixing ability and the production of leghemoglobin in soybean nodules formed by the inoculation of this mutant. In addition, this mutant strain hardly developed nitrogenase activity asymbiotically in contrast with the wild type strain, indicating that some nitrogen fixing gene might be blocked in this strain and the production of leghemoglobin could be decreased by the interference in nitrogen fixing genes.

• Korean Journal of Microbiology
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• v.14 no.1
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• pp.36-38
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• 1976

The insecticides, Dithane-M45 and copper sulfate, were introduced in this experiments to elucidate their effects on the nodulation of soybean plant(Glycine max Meer) by Rhizobium japonicum. The nodulation activity was inhibited in accordance with increase of their concentration.

• Microbiology and Biotechnology Letters
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• v.13 no.1
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• pp.79-85
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• 1985

Rhizobium japonicum wild type strains isolated from local soybean variety Jangback root nodules with higher nitrogenase activity than R. japonicum 3I1110 or 61A76 was mutangenized by N-methyl-N'-nitro-N-nitrosoguanidine and UV-irradiation, and screened by effectiveness assay with soybean. One mutant strain JB65 nodulated the roots earlier than the wild type and also expressed higher acetylene-reducing activity in the presence and absence of fixed nitrogen. The selected mutant was compared with SM35 strain and showed greater nodulation and symbiotic nitrogen fixing activity with local soybean variety Jangback than SM35 strain.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.345-350
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• 1986

In order to select suitable strains for utilization as soybean inoculants, the affinity between Rhizobium japonicum strains isolated from the domestic field and the several soybean varieties being distributed as recommended species was investigated by cross-inoculation experiments. The results obtained are as follows: 1. Rhizobium japonicum R-214 and R-138 showed broad affinity range to varies soybean species in terms of the nodule forming ability, the nitrogen fixing activity and the amount of total nitrogen absorption. In contrast, Rhizobium japonicum R-224 showed very low affinity to the same soybean groups. 2. The affinity of Hwang-Keum Kong and Jang-Paeck Kong to the rhizobium strains was the most signigicant, and that of Jang-Yeop Kong, Dong-Buk Tae, Paeck-Woon Kong and Dan-Yeop Kong was also significant. On the other hand, Pang-Sa Kong showed low affinity to the strains. 3. In general, the strains having high nitrogen-fixing activity seemed to possess the broad affinity range to the soybean hosts.

• Korean Journal of Microbiology
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• v.20 no.4
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• pp.195-200
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• 1982

Rhizobium japonicum was isolated from the nodule of soybean root grown at the reclaimed tidal land in Kang-Wha island. The effect of pH and salt concentration to the viability of the isolated strain were examined in relationship between microbial growth and accumulation of PHB. Optimal pH value for the good viability of the isolated strain was 7.0 and also, at 5.0 and 6.0 viability was favorable to large extent, but 9.0 was unfavorable. Examined the effect of salt concentration treated two times as of the salinity in the reclaimed tidal land, viability of the isolated strain showed about 30 to 40%. And also in treatment with NaCl(40g/l) whatever the pH value adopted, viability was mostly less than 10%. The amount of accumulated PHB was relatively high at low pH value(5-6) and at high salt concentrration, respectively.

• Applied Microscopy
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• v.8 no.1
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• pp.9-15
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• 1978

Five strains of the Genus Rhizobium were isolated from the nodules of five leguminous plants respectively. They were identified according to Bergey's Manual together with the results of Vincent. The flagella of each strains were observed by electron microscope using negative staining with PTA and metal shadowing with chromium. Five host plants and identified Rhizobium strains were as. follows. Pisum sativum.....R. leguminosarum Phaseolus vulgaris.....R. phaseoli Trifolium repens.....R. trifolii Glycine max.....R. japonicum Lupinus grandiflorus.....R. lupini Electron micrographs showed that R. leguminosarum and R. phaseoli had 4 peritrichous flagella, where as R. trifolii had 5 peritrichous flagella. On the other hand, R. japonicum and R. lupini had 1 subpolar flagellum.

• Korean Journal of Microbiology
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• v.22 no.2
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• pp.73-76
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• 1984

From the root nodules of legumes distributed in South Korea, 74 strains of Rhizobium were isolated. The strains isolated were identified based on Bergey's Manual and Vincent's identification key. Following 5 species of Rhizobium were confirmed. R. leguminosarum, R. meliloti, R. phaseoli, R. trifolii, and R. japonicum