• 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

• Applied Biological Chemistry
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• v.35 no.3
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• pp.179-185
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• 1992

Rhizobium meliloti populated in five Korean pasture soils were characterized by symbiotic effectiveness and intrinsic antibiotic resistance using whole-soil inoculum and 11 antibiotics, respectively. Most probable number (MPN) of naturalized rhizobia counted with alfalfa Vernal[Medicago sativa (L.)] as a host ranged $1.7{\times}10^2\;cells/g$. soil(Chunghyo, Kyeongiu)-$1.0{\times}10^5\;cells/g$. soil(Gampo, Kyeongiu) and ended to be positively associated with soil pH. On the whole, the effectiveness of population as compared to TAL mix inoculum (TAL 380+TAL 1372+TAL 1373) was very low. Nevertheless, there were two highly effective strains, YCK 539 and YCK 542, which were not inferior to TAL 1372, from Ogpo, Dalseong among the total of 30 of 6 isolates per each soil. As long as mean $N_2$ fixing ability of each soil isolate, the isolates from Hyeongog, Kyeonju were outstanding and the rest were in order of Ogpo, Dalseong>Chunghyo, Kyeongju>Hwaweon, Dalseong>Gampo, Kyeongiu. Isolates as a whole were resistant to erythromycin(67崙), nalidixic acid(77%), and streptomycin sulfate(8051), which had the concentration of $100\;{\mu}g/ml$, $160\;{\mu}g/ml$, and $10\;{\mu}g/ml$, respectively and divided into 14 patterns of resistance. Association between resistances in each soil was not clear. And there was no relationship of resistance pattern to effectiveness. The best effective strain YCKa 542 exclusively fell into No. X pattern having resistance to erythromycin, nalidixic acid, and neomycin sulfate.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.219-224
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• 1991

An acid tolerant R. meliloti "YA03" which was characterized through both acidified tube and pot soil experiment, was examined on its inoculation effect to alfalfa[Medicago sativa (L.)]cv. Vernal on hilly acid soil. It was conducted for 2 years to evaluate inoculation residual effect and there were two-fertilizer factors of nitrogen(0.8kg/10a) and lime(0,162kg/10a)as urea and $Ca(OH)_2$, respectively. The results obtained were summarized as follows : 1. In the 1st-year experiment, YA03 inoculated without nitrogen and lime application showed higher symbiotic effectiveness than check strains, YA026 and Rm2011 in nodule mass, $N_2$-fixing activity, and dry matter yield, but with N 8kg/10a application lower effectiveness than Rm2011. 2. In the 2nd-year experiment, Alfalfa dry matter yield by YA03 inoculation with N application(without lime) was 74% higher than that(276 kg/10a) in the 1st year, and the value showed 166%, 20%, and 21% increments as compared with noninoculated control(180kg/10a). YA026(399kg/10a), and Rm2011(397kg/10a), respectively. 3. In the 2nd-year experiment of N applicated plote(without lime), especially, YA03 showed higher shoot nitrogen(7.7kg N/10a/Yr.) fixed and soil rhizobial population($1{\times}10^4\;cells/g.\;soil$) than check strains. 4. On the basis of lime application, application effect of three major fertilizers with YA03 inoculation on alfalfa yield and soil rhizobial population was in the order of $N+P_2O_5+K_2O>P_2O_5+K_2O>P_2O_5+K_2O$. 5. On the whole, alfalfa yield by acid tolerant R. meliloti YA03 inoculation on hilly acid soil was enhanced with nitrogen application, and besides it appeared 44% higher with lime than without lime.

• 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.

• KSBB Journal
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• v.29 no.4
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• pp.244-249
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• 2014

Biosynthesis pathway of medium-chain-length (MCL) polyhydroxyalkanoates (PHA) from fatty acid ${\beta}$-oxidation pathway was constructed in recombinant Escherichia coli by introducing the Pseudomonas sp. 61-3 PHA synthase gene (phaC2) and the maoC genes from Pseudomonas putida, Sinorhizobium meliloti, and Ralstonia eutropha. The metabolic link between fatty acid ${\beta}$-oxidation pathway and PHA biosynthesis pathway was constructed by MaoC, which is homologous to P. aeruginosa (R)-specific enoyl-CoA hydratase (PhaJ1). When the E. coli W3110 strains expressing the phaC2 gene and one of the maoC genes from P. putida, Sinorhizobium meliloti, and Ralstonia eutropha were cultured in LB medium containing 2 g/L of sodium decanoate as a carbon source, MCL-PHA that mainly consists of 3-hydroxyhexanoate (3HHx), 3-hydroxyoctanoate (3HO) and 3-hydroxydecanoate (3HD), was produced. The monomer composition of PHA and PHA contents varied depending on MaoC employed for the production of PHA. The highest PHA content of 18.7 wt% was achieved in recombinant E. coli W3110 expressing the phaC2 gene and the P. putida maoC gene. These results suggest that MCL-PHA biosynthesis pathway can be constructed in recombinant E. coli strains from the b-oxidation pathway by employing MaoC able to supply (R)-3-hydroxyacyl-CoA, the substrate of PHA synthase.

• Korean Journal of Microbiology
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• v.27 no.4
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• pp.398-403
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• 1989

The root nodule of Canavalia lineta was classified as a determinate nodule and the symbiont as a Rhizobium-bacteriod based on their morphological characteristics. Isolated encosymbiont was similar both to R. leguminosarum and R. meliloti in its peritrichous arrangement of flagella and some of the physiological characteristics. Compared to control plants, Canavalia seedlings inoculated with the isolate grew normally due to induced root nodules, confirming isolate's infectivity and effectivity. Characteristics of the reisolated endosymbiont from induced root nodule were identical to those of the first isolate, indicating the nodules were induced by the first isolate. From these results, it was confirmed that Rhizobium strain isolated from the root nodules of Canavalia lineata was a real symbiont, and was named Rhizobium sp. SNU003.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.275-281
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• 1995

From the plasmid pYA300 carring a CMCase of Rhizobium fredii USDA193 plasmid was subcloned into pBluescript II KS(+)/pBluescript II SK(+) vectors and designated pYA500 and pYA600, respectively. Escherchia coli cells transformed with pYA500 porduced the CMCase more than with pYA600. The orientation of the cloned fragment in pBluescript vector had the effect on gene expression in E. coli background. When the 1.7 kb CMCase gene fragment of R. fredii USDA193 was hybridized to EcoRI-digested total DNA from R. meliloti and R. fredii USDA 191 the unique bands hybridized respectively, indicating that some genetic diversity exists in the EcoRI restriction enzyme site for CMCase gene in Rhizobium strains. The optimum pH of enzyme activity was 7 and the optimum temperature of that was nearly 37$\circ$C. The cellulase-minus derivatives of pYA500 were constructed by Tn5 insertional mutation. Among 6000 transconjugants, two mutant plasmids (designated pYA500::Tn5a and pYA500::Tn5b) were detected from the cellulase- negative transconjugants. The product of CMCase gene was analyzed by one dimensional SDS- PAGE of the cell extracts. About 45 kDa protein was considered to be a product of CMCase gene.

• Journal of Microbiology
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• v.38 no.3
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• pp.176-179
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• 2000

A challenge phage system was used to study the DNA-protein interaction between C4-dicarboxylic acid transport protein D(DCTD) or $\sigma$54, and a $\sigma$54 -dependent promoter, dctAp. R. meliloti dctA promoter regulatory region replaced the Omnt site on the phage. S. typhimurium strains overproducing either DCTD or $\sigma$54 directed this challenge phage towards lysogency, indicating that DCTD or E$\sigma$54 recognized the dctA promoter on the phage and repressed transcription of the ant gene. These challenge phage constructs will be useful for examining interactions between DCTD(or $\sigma$54) and the dctA promoter region.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1338-1342
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• 2004

Cyclosophoraoses (Cys), cyclic ${\beta}-(1{\rightarrow}2)-D-glucans$ produced by Rhizobium meliloti 2011, were used as a novel chiral stationary phase for the enantiomeric separation. A novel Cys stationary phase, chemically immobilized onto porous silica via aminopropyltrimethoxysilane as a molecular linker, showed good separation for each racemate of bupivacain (separation factor, $\alpha$=1.3), propranolol ($\alpha$=1.3), and fenoprofen ($\alpha$=2.9), respectively, under the mobile phase of water: methanol (80:20, v/v) at a constant flow rate of 0.9 ml/min at pH7.

• Korean Journal of Agricultural Science
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• v.8 no.2
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• pp.238-243
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• 1981

This experiment was carried out to study the availability of Korean peat as a main carrier material of rhizobial inoculant, using the alfalfa strain Rhizobium meliloti M 14 which was isolated in the previous report. Modification of powdered peat with calcium carbonate and other materials was studied; inoculation of the peat with culture broth, maturation of the mixture under different conditions, and survival of the strain in the peat culture was examined. The results obtained were as follows. 1. Peat produced in Pyongtak was highly acidic, pH 3.8, and addition of calcium carbonate by 14% was required for pH adjustment to 6.4. However the amount of calcium carbonate could be reduced by 4 to 8% when carbon or charcoal was mixed with the peat. 2. Viable number of the strain reached to $7-9{\times}10^9cells/g$ after 3 days, when inoculated with the culture broth of early stationary growth phase and matured in unsteriled peat of open trays; and the number in steriled peat was $1.1-6.2{\times}10^{10}cells/g$ after 5 days, when matured in closed bottles. 3. Survival of the strain was affected markedly by storage temperature, and positive effect of D-sorbitol on the viability was recognized at elevated temperatures, when added as an additional carbon source and moistening agent. Glycerol, sorbitol, or sodium lactate was utilized by the strain as a sole source of carbon, and the decimal reduction time of viable number in the peat culture was was found to be 8 to 9 weeks at $25^{\circ}C$ when these agents were added by 0.5%.