• Title/Summary/Keyword: Rhizobium

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Rhizobium meliloti 102F51 Mutants Defective in Heme Synthesis (Heme 합성특성이 다른 Rhizobium meliloti 102F51 Mutant의 선별)

  • 최영주;정원화;김경수;신평균;조무제
    • Korean Journal of Microbiology
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    • v.24 no.2
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    • pp.98-105
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    • 1986
  • Rhizobium meliloti 102 F 51, the symbiotic partner of alfalfa, was mutagenized with N-methyl-N'-nitro-N-nitrosoguanidine (NTG) and UV-irradiation. Three group of mutants which form white, white-pink and red nodules were selected. The adetylene reduction activity, nodulation activity, amount of heme synthesis during the nodulation, and ${\delta}-aminolevulinic$ acid synthetase (ALAS) and ${\delta}-aminolevulinic$ acid dehydratase (ALAD) activities in free living rhizobia and bacteroid states of the each group of mutants were compared. The mutants forming white nodules showed lower acetylene reduction activity compared to those of red nodule forming mutants. The two key enzymes for the heme synthetic pathway, ALAS and ALAD activities of the mutants forming red nodules was much higher than those of the mutants forming white nodules in bacteroid state, however no significant difference was observed in free living state. In the nodules the ALAS was detected only in bacteroid fraction, while ALAD was detected both in bacteroid and plant fraction. ALAS was dramatically increased with the heme synthesis during the nodulation, while ALAD was decreased in plant fraction but slight increase was observed in bacteroid fraction.

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Effects of Osmoprotectants on the Growth and Nitrogenase Activity of Rhizobium and Azospirillum under Osmotic Stress (질소고정균의 성장과 질소고정력에 대한 osmoprotectant의 영향)

  • Gal, Sang-Wan;Choi, Young-Ju
    • Applied Biological Chemistry
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    • v.41 no.1
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    • pp.53-59
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    • 1998
  • The Rhizobium and Azospirillum spp. were isolated from the root nodules of several leguminous plants and rhizosphere of various paddy rice varieties. The growth of the nitrogen-fixing strains isolated was largely inhibited in yeast extract-mannitol medium (AMA) containing 0.6 M NaCl. In response to osmotic stress, the nitrogen-fixing strains accumulate intracellular free glutamate. The growth and nitrogenase activity of Rhizobium and Azospirillum were increased by addition of osmoprotectants such as proline, glycine betaine, and glutamate during salt stress. Glycine betaine was the most effective among exogenous osmoprotectants tested. In the absence of sodium chloride, nitrogenase activity seem to be slightly decreased by the presence of the proline or glycine betaine. These results revealed that nitrogenase activity was repressed by fixed nitrogens such as proline or glycine betaine.

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The effect of environmental factors affecting to the growth of Rhizobium japonicum (Rhizobium japonicum의 생장 및 poly$\beta$hydroxybutyric acid(PHB)의 축적에 미치는 환경요인의 영향)

  • 이기성;최영길
    • 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.

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Identification of Amino Acid Residues in the Carboxyl Terminus Required for Malonate-Responsive Transcriptional Regulation of MatR in Rhizobium leguminosarum bv. trifolii

  • Lee, Hwan-Young;Kim, Yu-Sam
    • BMB Reports
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    • v.34 no.4
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    • pp.305-309
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    • 2001
  • MatR in Rhizobium trifolii is a malonate-responsive transcription factor that regulates the expression of genes, matABC, enabling decarboxylation of malonyl-CoA into acetyl-CoA, synthesis of malonyl-CoA from malonate and CoA, and malonate transport. According to an analysis of the amino acid sequence homology, MatR belongs to the GntR family The proteins of this family have two-domain folds, the N-terminal helix-turn-helix DNA-binding domain and the C-terminal ligand-binding domain. In order to End the malonate binding site and amino acid residues that interact with RNA polymerase, a site-directed mutagenesis was performed. Analysis of the mutant MatR suggests that Arg-160 might be involved in malonate binding, whereas Arg-102 and Arg-174 are critical for the repression activity by interacting with RNA polymerase.

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Identification of Malonate-specific Enzymes, Malonyl-CoA Synthetase and Malonamidase, in Rhizobia (Rhizobia에서 Malonyl-CoA synthetase와 Malonamidase의 확인)

  • Kim, Yu-Sam;Chae, Ho-Zoon;Lee, Eun;Kim, Yong-Sung
    • Korean Journal of Microbiology
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    • v.29 no.1
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    • pp.40-48
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    • 1991
  • Two malonate-specific enzymes, malonyl-CoA synthetase and malonamidase, were found in free-living cultures of Rhizobium japonicum, Rhizobium meliloti, and Rhizobium trifolii, that infect plant roots where contain a high concentration of malonate. Malonyl-CoA synthetase catalyzes the formation of malonyl-CoA, AMP, and PPi directly from malonate, coenzyme A, and ATP in the presence of $Mg^{2+}$ Malonamidase is a novel enzyme that catalyzes hydrolysis and malonyl transfer of malonamate, and forms malonohydroxamate from malonate and hydroxylamine. Both enzymes are highly specific for malonate. These results show that Rhizobia have enzymes able to metabolize malonate and suggest that malonate may be used in symbiotic carbon and nitrogen metabolism.

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Association of Colony Morphology with Coenzyme $Q_{10}$ Production and Its Enhancement from Rhizobium radiobacter T6102W by Addition of Isopentenyl Alcohol as a Precursor

  • Seo, Myung-Ji;Kook, Moo-Chang;Kim, Soon-Ok
    • Journal of Microbiology and Biotechnology
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    • v.22 no.2
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    • pp.230-233
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    • 2012
  • Rhizobium radiobacter T6102 was morphologically purified by the aniline blue agar plates to give two distinct colonies; white smooth mucoid colony (T6102W) and blue rough colony (T6102B). The coenzyme $Q_{10}$ ($CoQ_{10}$) was produced just by T6102W, showing 2.0 mg/g of $CoQ_{10}$ content, whereas the T6102B did not produce the $CoQ_{10}$. All of the used $CoQ_{10}$ biosynthetic precursors enhanced the $CoQ_{10}$ production by T6102W. Specifically, the supplementation of 0.75 mM isopentenyl alcohol improved the $CoQ_{10}$ concentration (19.9 mg/l) and content (2.4 mg/g) by 42% and 40%, respectively.

Studies on the Response of Rhizobium Inoculation and Nitrogen Concentration to the Soybean Growth in Nutri-Culture I. Effects of Rhizobium Inoculation and Nitrogen Concentration on the Nodulation, Total and Allantoin Nitrogen Contents of the Plants, and Contents of crude fat and Protein of Soybean Seeds in Nutri-Culture (양액재배(養液栽培)에 있어 근류균(根瘤菌)의 접종(接種) 및 질소반응(窒素反應)에 관(關)한 연구(硏究) 1. 근류균(根瘤菌)의 접종(接種) 및 질소시용량(窒素施用量)이 대두품종(大豆品種)의 근류착생(根瘤着生), 전질소(全窒素) 및 Allantoin 질소함량(窒素含量)과 종실중(種實中)의 조지방(粗脂昉) 및 조단백함량(粗蛋白含量)에 미치는 영향(影響))

  • Lee, Hong-Suk;Ku, Ja-Hwan
    • Korean Journal of Soil Science and Fertilizer
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    • v.22 no.3
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    • pp.245-252
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    • 1989
  • This experiment was carried out to study the effects of nitrogen concentration of cultural solution, rhizobium inoculation, and planting density on nodulation, contents of total-N and allantoin-N of the plants, and contents of crude fat and protein of the seeds with 4 cultivars and 1 non-nodulation isogenic line (Hwangeumkong, Jangbaegkong, Paldalkong, Clark, non-nodulating Clark) in nutri-culture. Modulation was increased significantly by the rhizobium inoculation and decreased by the increase of nitrogen concentration of the cultural solution and planting density, and more nodule per plant was observed in Hwangeumkong than other cultivars. Total nitrogen contents of the soybean plant were higher in Hwangeumkong and Janbaegkong compared with other two cultivars, and were increased by rhizobium inoculation and the increase of nitrogen concentration of the cultural solution except in case of $R_3$ stage of non-inoculation of rhizobium, and was decreased by the increase of planting density. Allantoin nitrogen contents of stem were lower in Paldalkong compared with other cultivars and was increased significantly by the rhizobium inoculation, and thus was correlated significantly with nodulation. Allantoin-N contents were also decreased by the increase of planting density and nitrogen concentration of the solution, and was very low in case of non-nodulating isogenic line at any level of nitrogen concentration. The contents of crude fat of the seed were lower in cases of higher nitrogen concentration of the solution and more plants per pot, but no effects of rhizobium inoculation was observed. The contents of crude protein were tend to increase by the increase of nitrogen concentration, but were little effected by rhizobium inoculation and planting density.

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Host Specificities Between Soybean Varieties and Rhizobium japonicum Strains (대두품종(大豆品種)과 선발(選拔) Rhizobium japonicum간의 숙주(宿主) 친화성(親和性))

  • Kim, Chang-Jin;Rhee, Yoon;Kim, Sung-Hoon;Yoo, Ick-Dong;Mheen, Tae-Ick
    • 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.

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Phylogenetic analysis of the genera Azorhizobium, Bradyrhizobium, Mesorhizobium, Rhizobum and Sinorhizobium on the basis of internally transcribed spacer region (ITS 영역의 염기서열을 이용한 근류형성 질소고정균의 계통분류)

  • Kwon, Soon-Wo;Kim, Chang-Yung;Ryu, Jin-Chang;Go, Seung-Joo
    • Korean Journal of Soil Science and Fertilizer
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    • v.35 no.1
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    • pp.12-26
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    • 2002
  • The phylogenetic relationships for 33 strains belonging to the genera Azorhizobium, Bradyrhizobium, Mesorhizobium, Rhizobium and Sinorhizobium were conducted by the sequence analyses of the ITS regions. The sequence homologies of these strains showed the high variations(28.0 - 94.9%). According to the phylogenetic analysis of ITS regions. 37 ITS clones from 33 strains of 32 species were classified into four groups. Group I included all strains of the genus Sinorhizobium as core members and R. giardinii as a peripheral member. The genus Rhizobium strains were clustered into group II which was very heterogeneous and the tree toplogy of this group were very unstable. Among the members of group II. the taxonomic position of R. radiobacter and R. rubi was not clearly identified on the basis of ITS I regions. R. undicola and R. vitis were remotely related with other Rhizobium strains including R. leguminosarum, R. galegae, R. gallicum, R. mongolense, R. tropici, R. hainanense, R. rhizogense and R. huautlense of group II were supposed to be loosely related to R. leguminosarum. While the stains of the genera Bradyrhizobium constituted group III with Azorhizobium caulindans, the strains of the genus Mesorhizobium formed group IV on the relatively high sequence homology level.

Effects of inoculation with selected Rhizobium japonicum on the yield, nodule formation and nitrogen fixing activity of soybean(Glycine max) (선발대두근류균(選拔大豆根瘤菌)의 접종(接種)의 대두근류형성(大豆根瘤形成) 질소고정호성(窒素固定浩性) 및 수량(收量)에 미치는 영향(影響))

  • Yoo, Ick-Dong;Kim, Chang-Jin;Rhee, Yoon;Kim, Seok-Dong;Hong, Eun-Hi
    • Korean Journal of Soil Science and Fertilizer
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    • v.21 no.1
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    • pp.55-60
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    • 1988
  • To develop soybean inoculant the effects of inoculation with selected Rhizobium japonicum strains were tested in the field, and the results were as following. 1. With the inoculation of selected strains, increase of nodule number, nodule weight and nitrogen fixing activity were observed with or without applying N-fertilizer. 2. Chlorophyll contents was increased and senescence of plant was delayed with the inoculation of selected strains in case without applying N-fertilizer. But there was little difference of chlorophyll contents in case with applying N-fertilizer. 3. There were little differences of plant height and number of nodes, and some increase of plant stem dry matter and number of pods with inoculation of selected strains. 4. The mean yield of inoculation group (363-374kg/10a) was increased by 8-11% comparing to the uninoculated group (337kg/10a) in case without applyiag N-fertilizer. The mean yield of inoculated group (368-384kg/10a) was increased by 9-14% also in case with applying N-fertilizer.

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