• Microbiology and Biotechnology Letters
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• v.14 no.2
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• pp.187-192
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• 1986

The inoculation effect of the highly nitrogen fixing strains of R. japonicum were tested in the 3 kinds of soil with different cultural history onto Gycine max cv. Jang-yeob. The nodulation and nitrogen fixation activity in 3 test soils all showed the great increase in inoculated group compared to the non-inoculated group. The plant dry weight of the in-oculated groups were increased about 10% than that of the non-inoculated groups. The numerical index of the increase in total nitrogen fixation activity were 238% in the pre-cultivated, 266% in the immatured and 157% in the matured soil and these results suggested the clear effect of inoculation. Among the strains tested, R. japonicum R214 and Rl38 showed the excellent inoculation effect.

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.1045-1048
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• 2007

Two genes, dps encoding decaprenyl diphosphate synthase and dxs encoding 1-deoxy-D-xylulose 5-phosphate synthase, were isolated from Rhizobium radiobacter ATCC 4718. DNA sequencing analysis of the dps and dxs genes revealed an open reading frame of 1,077 bp and 1,920 bp, respectively. The heterologous expression in Escherichia coli BL21(DE3) was carried out in order to identify their functions. Recombinant E. coli BL21(DE3) harboring the dps gene produced $CoQ_{10}$ as well as $CoQ_8$ and $CoQ_9$, whereas E. coli harboring only the dxs gene produced more $CoQ_8$ compared with the wild-type E. coli. Additionally, the coexpression of dps and dxs genes in E. coli was carried out. The recombinant E. coli harboring only the dps gene produced $0.21{\pm}0.04\;mg/l$ of $CoQ_{10}$, whereas the coexpressed E. coli with dps and dxs genes produced $0.37{\pm}0.07\;mg/l$ of $CoQ_{10}$. HPLC analysis also showed that the $CoQ_{10}$ fraction (100% of the total CoQs distribution) was increased from $15.86{\pm}0.66%$ (only dps) to $29.78{\pm}1.80%$ (dps and dxs).

• Journal of Microbiology and Biotechnology
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• v.24 no.9
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• pp.1162-1169
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• 2014

Glyphosate is the active component of the top-selling herbicide, the phytotoxicity of which is due to its inhibition of the shikimic acid pathway. 5-Enolpyruvylshikimate-3-phosphate synthase (EPSPS) is a key enzyme in the shikimic acid pathway. Glyphosate tolerance in plants can be achieved by the expression of a glyphosate-insensitive aroA gene (EPSPS). In this study, we used a PCR-based two-step DNA synthesis method to synthesize a new aroA gene ($aroA_{R.\;leguminosarum}$) from Rhizobium leguminosarum. In vitro glyphosate sensitivity assays showed that $aroA_{R.\;leguminosarum}$ is glyphosate tolerant. The new gene was then expressed in E. coli and key kinetic values of the purified enzyme were determined. Furthermore, we transformed the aroA gene into Arabidopsis thaliana by the floral dip method. Transgenic Arabidopsis with the $aroA_{R.\;leguminosarum}$ gene was obtained to prove its potential use in developing glyphosate-resistant crops.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.1
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• pp.43-46
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• 1979

Curing the studies on the mechanism of the nodule formation and the infection of rhizobia using the continously cultured plant cell tissues, it was found that some calluses possess high nitrogen fixation activity. This experiment was conducted to know the differences among the calluses and the Rhizobia. The results obtained were as follows; 1) In a single inoculation the nitrogenase activity of soybean cell cultures-rhizobium was moderately higher than non-leguminous cell cultures, however, in the mixing inoculation that was reversely found. 2) Host factor, which was characteristics for the nodule formation and the nitrogenase activity, was not appeared generally in the plant cell cultures except for Kuamusume and Toyozuzu in soybean, and Datura in non-leguminous cell cultures. 3) In the 012 rhizoblium cultured on soybean cell cultures and in the 010, 023 and 024 rhizobia cultured on non-leguminous cell cultures the nitrogenase activity higher than the others.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.551-555
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• 1997

This experiment was carried out to elucidate the biological activity and absorption characteristics of flavonoids in Rhizobium and Bradyrhizobium and to obtain basic information on host specific nodulation by flavonoids in rhizobium-legume symbiosis. The purpose of the present study was to explore the biological activity and the flavonoid absorption indicates that host-specificity is induced by flavonoids in symbiotic nitrogen fixation. Biological activity increased by daidzein and genistein treatment on B. japonicum KCTC 1539 whereas decreased by luteolin treatment but increased by luteolin treatment on R. meliloti whereas decreased by daidzein and genistein treatment. Daidzein and genistein are absorbed by B. japonicum, KCTC 1539 at higher rate than other flavonoids. Especially, luteolin was absorbed at a least rate. Luteolin are absorbed by R. meliloti KCTC 2353 at higher rate than other flavonoids. Especially, daidzein and genistein was absorbed at a least rate.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.562-573
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• 2017

Some symbiotic characteristics of native Korean Rhizobium leguminosarum biovar viciae were analysed to get some informations desirable for cultivation of hairy vetch (Vicia villosa Roth) using its symbiont in Korea. The size of indigenous populations of R. leguminosarum biovar viciae was higher in seven upland soils showing $1.7{\times}10^2{\sim}5.8{\times}10^4cells\;g{\cdot}soil^{-1}$, which appeared to be 10% and 37% higher for cultivated and uncultivated soils of hairy vetch, respectively, than seven paddy soils with $1.7{\times}10^2{\sim}1.7{\times}10^4cells\;g{\cdot}soil^{-1}$. In symbiotic potentials, however, the yields of hairy vetch treated with 10-fold-diluted ($10^{-1}$) inoculum and 1000-fold-diluted ($10^{-3}$) one was 11.2% and 8.8% more, respectively, in paddy than upland. Hairy vetch inoculated with either strain KHR 106 from Sacheon or strain KHR 120 from Yesan among native Korean R. leguminosarum biovar viciae isolates was of similar yield increment of 16% (p < 0.05) in upland soils with native R. leguminosarum biovar viciae of $5.8{\times}10cells\;g{\cdot}soil^{-1}$. In case of coinoculation of the two strains, however, the yields was not significantly increased. In especial, isolate KHR 106, KHR 120, and KHR 122 from Suwon, which has also good symbiotic effectiveness, showed different protein profile patterns each other. As a result, hairy vetch is possibly able to use atmospheric nitrogen through symbiotic relationship with diverse native R. leguminosarum biovar viciae in Korean arable lands. For safe and good production of hairy, however, the use of superior strains with high symbiotic effectiveness and competitiveness will be desirable.

• Journal of Ginseng Research
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• v.45 no.3
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• pp.442-449
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• 2021

Background: Panax ginseng is an important crop in Asian countries given its pharmaceutical uses. It is usually harvested after 4-6 years of cultivation. However, various abiotic stresses have led to its quality reduction. One of the stress causes is high content of heavy metal in ginseng cultivation area. Plant growth-promoting rhizobacteria (PGPR) can play a role in healthy growth of plants. It has been considered as a new trend for supporting the growth of many crops in heavy metal occupied areas, such as Aluminum (Al). Methods: In vitro screening of the plant growth promoting activities of five tested strains were detected. Surface-disinfected 2-year-old ginseng seedlings were dipping in Rhizobium panacihumi DCY116^T suspensions for 15 min and cultured in pots for investigating Al resistance of P. ginseng. The harvesting was carried out 10 days after Al treatment. We then examined H₂O₂, proline, total soluble sugar, and total phenolic contents. We also checked the expressions of related genes (PgCAT, PgAPX, and PgP5CS) of reactive oxygen species scavenging response and pyrroline-5-carboxylate synthetase by reverse transcription polymerase chain reaction (RT-PCR) method. Results: Among five tested strains isolated from ginseng-cultivated soil, R. panacihumi DCY116^T was chosen as the potential PGPR candidate for further study. Ginseng seedlings treated with R. panacihumi DCY116^T produced higher biomass, proline, total phenolic, total soluble sugar contents, and related gene expressions but decreased H₂O₂ level than nonbacterized Al-stressed seedlings. Conclusion: R. panacihumi DCY116^T can be used as potential PGPR and "plant strengthener" for future cultivation of ginseng or other crops/plants that are grown in regions with heavy metal exposure.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.2
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• pp.137-140
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• 1982

Three levels of inoculum concentration from 10 to 30 percent, three kinds of adhesive materials, gum arabic, methyl cellulose and carboxy methyl cellulose, and five different pelleting materials including 4 different sources of lime and calcium carbonate were compared to investigate an optimum condition for seed inoculation by counting the number of viable rhizobium cells. For a peat-cultured Rhizobium inoculant, 10 per cent was found to be an optimum by showing 3.5 $\times$ 10$^9$ viable cells per seed. The highest number of viable cells were observed from gum arabic at 40 per cent, methyl cellulose at 5 per cent and carboxy methyl cellulose at 4 per cent. Among pelleting materials, a dental lime for investment originated from Ransom & Randolph Co. Ohio, U.S.A. resulted best as pelleting material.

• Korean Journal of Agricultural Science
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• v.11 no.2
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• pp.322-327
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• 1984

As a basic studies for the laboratory scale production of alfalfa inoculum, Rhizobium meliloti M14 was characterized for its carbon and nitrogen sources, and some parameters for broth cultivation in a chemostat were studied by semi-continuous operation. The result s obtained were as follows. 1. Growth rate of the strain was increased by disaccharides than by monosaccharides tested, and pentoses resulted in poor growth than hexoses. Sugar alcohols including inositol supported the best growth among sugars. 2. Mannitol in the yeast-mannitol-broth was substituted by natural carbon sources such as malt extract or molasses. 3. Ten per cent of fresh yeast water appeared to supply enough amount of growth factor s for the strain, and the effect was equivalent to 0.24 percent of the commercial yeast extract powder. 4. Batch growth of the stain in a chemostat, New Brunswick Micro Ferm 28L, reached in the early stationary growth phase of $5{\sim}7{\times}10^9cells/ml$ after 36 hours of incubation. The culture at this stage was switched to semi-continuous cultivation, and the culture broth of four-fifth of the working volume was recovered every 24 hours when the maximal count was obtained.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.278-285
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• 2010

We examined the distribution of exopolysaccharide (EPS) producing bacteria population in rhizosphere soils of domestic medicinal herbs; Angelica sinensis, Atractytodes japonica, Achyranthes japonica, Anemarrhena asphodeloides, and Astragalus membranaceus. Fifty-six percent of the total isolates from rhizosphere soil of Angelica sinensis were EPS producing bacteria, suggesting the dominance of EPS producing bacteria in rhizosphere soil of Angelica sinensis. EPS producing bacteria were enumerated in root system (rhizosphere soil, rhizoplane, inside of root) of Angelica sinensis. Bacterial density of rhizosphere soil, rhizoplane, and inside of root were distributed $9.0{\times}10^6CFU/g{\cdot}soil$, $7.0{\times}10^6CFU/g{\cdot}soil$, and $1.4{\times}10^3CFU/g{\cdot}soil$, respectively. EPS producing bacteria from rhizosphere soil were categorized into five major phylogenetic groups: Alphaproteobacteria (4 strains), Betaproteobacteria (6 strains), Firmicutes (2 strains), Actinobacteria (3 strains), and Bacteroidetes (1 strain) subdivisions. Also, the EPS producing isolates from rhizoplane were distributed as 7 strains in Alphaproteobacteria, 3 strains in Betaproteobacteria, 2 strains in Actinobacteria, 3 strains in Bacteroidetes, and 1 strain in Acidobacteria subdivisions. All of the EPS producing bacteria inside of root belong to genus Chitinophaga. Burkholderia caribiensis DR14, Terriglobus sp. DRP35, and Rhizobium hainanense SAP110 were selected in 112 EPS producing bacteria. These appeared to have produced high levels of exopolysaccharide 6,555 mpa.s, 3,275 mpa.s, and 1,873 mpa.s, respectively. The purified EPS was analyzed Bio-LC. As neutral sugars, glucose, galactose, mannose were detected and as amino sugars, galactosamine and glucosamine were detected. Especilally, analysis of Bio-LC showed that Rhizobium hainanense SAP110 produced glucose (60~89%) and glucosamine (8.5%) as major neutral sugar and amino sugar, respectively.