• 한국작물학회지
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• 제48권4호
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• pp.308-315
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• 2003

A field experiment was conducted to investigate the performance of three legume species in a zero-tillage, non-fertilized rice field in a temperate zone. Before the experiment for 5 years, from 1995 to 1999, plant growth patterns of three legume species grown as over-wintering (October-May) cover crops on a paddy field were maintained to study N balance and $\textrm{N}_2$ fixation. Decrease in plant density accelerated from after winter to flowering from 1,090, 320, and 5 to 732, 232, and 6 plants $\textrm{m}^{-2}$ in Chinese milk vetch (CMV), white clover (WC), and hairy vetch (HV), respectively. Total dry weights of plants above-ground level were 0.05, 0.11, and 2.43 g $\textrm{plant}^{-1}$. in WC, CMV and HV respectively but steeply increased at ripening up to 0.77, 2.33, and 26 g $\textrm{plant}^{-1}$. The root dry weight of HV and CMV rapidly increased while in WC, root dry weight increased slightly towards flowering. The highest nodule numbers were recorded in CMV to April thereafter WC produced the highest. Nodule size was distributed within 7mm in CMV but it was larger in HV varying from 1 to 10mm. Shoot N (g $\textrm{m}^{-2}$) greatly increased from over-wintering to flowering in CMV, HV and WC and it ranged from 1.66, 0.5 and 1.92 to 12.6, 3.1 and 13.02 g $\textrm{m}^{-2}$, respectively. After wintering, the initial shoot N content (%) was more in CMV. Root N content (%) was constant or slightly decreased in HV and WC. Soil total N in the control plot (clean fallow) was the highest on Mar. 2 then decreased rapidly to flowering. Soil N content was constant in HV plots whereas it was low in WC plots for the entire growth period except just after winter. Maximum nitrogenase activities were 9, 37.8, and 131 mol $\textrm{C}_2\textrm{H}_4$ $\textrm{plant}^{-1}$ $\textrm{hour}^{-1}$. in CMV, HV, and WC, respectively. Nitrogenase activity showed a direct correlation with nodule number, size and fresh weight. As a cover crop preceding a rice crop, CMV is more suited to colder regions due to its earlier ripening characteristics. Hairy vetch and WC are recommended for regions with a mild winter and a long summer owing to their late ripening and great N fixation activity.

• 미생물학회지
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• 제28권2호
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• pp.151-157
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• 1990

식물근권에서 분리된 협생의 미호기성 및 내산성인 A. amazonense Kpl의 질소고정은 용존산소농도 0.2 KPa에서 최대활성을 보였다. 혐기상태 또는 고농도의 산소조건에서는 가역적으로 활성이 저해되였고, 암모늄처리는 350mM 농도까지 점차적으로 활성을 억제하였다. 최대 질소고정활성을 갖는 균체로부터의 효소추출액을 DEAE-52 크로마토그래피, 열처리 및 PAGE에 의해 순수분리한 질소고정효소계인 MoFe 단백질은 분자량이 210,000달톤으로 55,000 및 50,000 달톤인 각각 2개의 서브유닛트를 갖고,2원자의 MO,24원자의 Fe 및 28원자의 S를 함유하며, 등전점이 5.2 그리고 최대비활성이 2,200nM $C_2H_4mg^{-1} min^{-1}$였다. Fe 단백질은 분자량이 66,000달톤으로 35,000 및 30,000달톤인 서브 유닛트로써 구성되고, 4원자의 Fe 및 6원자의 S를 함유하며, 등전점이 4.6으로 산성이고, 최대비활성이 1.700nM $C_2H_4mg^{-1} min^{-1}$였다. 이 효소계는 pH7, 온도 $35^{\circ}C$에서 최척할성을 나타내었고, $4^{\circ}C$에서 MoFe 단백질과 Fe단백질은 각각 30일과 10일 정도 활성을유지하였다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1986년도 춘계 학술대회지
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• pp.64-65
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• 1986

• 미생물학회지
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• 제24권3호
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• pp.317-322
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• 1986

It was observed that the strains of Klebsiella pneumoniae isolated from rhizosphere of rice, capable of utilizing chlorivated hervicides, such as 2, 4-dichlorophenoxyacetate, 2-methyl-4-chlorophenoxyacetate and 3-chlorobenzoate, as sole source of carbon and energy and confirmed that their degrading ability of the herbicides was due to plasmid genes. Characteristics of selected strains such as nitrogenase activity, resistances to antibiotics and heavy metal ion were measured.

• Bulletin of the Korean Chemical Society
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• 제27권1호
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• pp.35-36
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• 2006

• Mycobiology
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• 제33권1호
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• pp.51-60
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• 2005

Pot greenhouse experiments were carried out to attempt to increase the salinity tolerance of one of the most popular legume of the world; cowpea; by using dual inoculation of an Am fungus Glomus clarum and a nitrogen-fixer Azospirillum brasilense. The effect of these beneficial microbes, as single- or dual inoculation-treatments, was assessed in sterilized loamy sand soil at five NaCl levels ($0.0{\sim}7.\;2ds/m$) in irrigating water. The results of this study revealed that percentage of mycorrhizal infection, plant height, dry weight, nodule number, protein content, nitrogenase and phosphatase activities, as well as nutrient elements N, P, K, Ca, Mg were significantly decreased by increasing salinity level in non-mycorrhized plants in absence of NFB. Plants inoculated with NFB showed higher nodule numbers, protein content, nitrogen concentration and nitrogenase activities than those of non-inoculated at all salinity levels. Mycorrhized plants exhibited better improvement in all measurements than that of non-mycorrhized ones at all salinity levels, especially, in the presence of NFB. The concentration of $Na^+$ was significantly accumulated in cowpea plants by rising salinity except in shoots of mycorrhizal plants which had $K^+/Na^+$ ratios higher than other treatments. This study indicated that dual inoculation with Am fungi and N-fixer Azospirillum can support both needs for N and P, excess of NaCl and will be useful in terms of soil recovery in saline area.

• Environmental Engineering Research
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• 제12권4호
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• pp.136-147
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• 2007

In an effort to identify possible microbes for seeking bioagents for remediation of herbicide-contaminated soils, seven species of phototrophic nonsulfur bacteria (Rhodobacter capsulatus and sphaeroides, Rhodospirillum rubrum, Rhodopseudomonas acidophila, blastica and viridis, Rhodomicrobium vannielii) were grown in the presence of the herbicide, butachlor, and bacterial growth rates and nitrogen fixation were measured with different carbon sources. Under general conditions, all species showed 17-53% reductions in growth rate following butachlor treatment. Under nitrogen-fixing conditions, Rb. capsulatus and Rs. rubrum showed 1-4% increases in the growth rates and 2-10% increases in nitrogen-fixing abilities, while the other 5 species showed decreases of 17-47% and 17-85%, respectively. The finding that Rp. acidophila, Rp. blastica, Rp. viridis and Rm. vannielii showed stronger inhibitions of nitrogenase activity seems to indicate that species in genera Rhodobacter and Rhodospirillum are less influenced by butachlor than those in Rhodopseudomonas and Rhodomicrobium in terms of nitrogen-fixing ability. Overall, nitrogenase activity was closely correlated with both growth rate and glutamine synthetase activity (representing nitrogen metabolism). When the carbon sources were compared, pyruvate (three carbons) was best for all species in terms of growth rate and nitrogen fixation, with malate (four carbons) showing intermediate values and ribose(five carbons) showing the lowest; these trends did not change in response to butachlor treatment. We verified that each of the 7 species had a plasmid ($12.2{\sim}23.5\;Kb$). We found that all 7 species could use butachlor as a sole carbon source and 3 species were controlled by plasmid-born genes, but it is doubtful whether plasmid-born genes were responsible to nitrogen fixation.

• 한국미생물·생명공학회지
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• 제46권2호
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• pp.154-161
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• 2018

현재 도시의 도시열섬현상을 완화시키는 방안으로 도시 녹화사업 및 연구가 주목 받고 있다. 이 연구에서는 질소고정균을 분리하고, 식물 성장에 미치는 영향을 확인했다. 먼저 질소고정 균을 분리하기 위해, 질소원이 없는 배지에서 enrichment를 실시했고, 질소원이 제한된 배지에서 높은 성장을 보인 colony를 분리하여 순수분리 했다. 순수 분리된 균은 ARA를 통해 acetylene이 90% 이상 감소되고, ethylene 생성을 통해 nitrogenase의 활성을 간접적으로 확인했다. 재현성이 확인된 Cedecea sp. MK7과 Enterobacter sp. Y8을 선별했다. 선별된 질소고정 균을 perennial rye grass의 성장에 적용한 결과 건조중량이 18.65 mg인 대조군에 비해 34.80 mg (186.60%)으로 증가한 것을 확인했다. 식물 성장 후, 질소고정 균이 접종된 토양의 미생물 군집 분석은 대조군과 유사했다. 따라서 본 연구에서는 도시녹화 시스템에 질소고정 균을 이용하여 식물 성장을 촉진한다면 그 효율이 증대될 것이다.

• The Korean Journal of Ecology
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• 제18권1호
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• pp.43-54
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• 1995

Effects of environmental factors of N, P, pH, moisture, temperature and oxygen on growth and nitrogen fixation activity of kummerowia striate (Thunb.) Schindler seedling, bearing symbiotic root nodules, were quantitatively analyzed during the growing period. The specific nitrogenase activity (ARA) of nodules showed the maximum value of 187 μmol C₂H₄g fr wt-1 h-1 6 weeks after seeds were germinated. The total nitrogenase activities per plant attained as 1.56, 0.85, 0.09 and 4.0, 1.11, 0.04 μmol C₂H₄hr-1, respectively for the treatments of 1, 3 and 5 mM NO₃￣and NH₄＋ on the 60th day. While the plant grown in N-free media for 20 days after treatments of 5 mM NH₄+for 40 days resulted in 30 mg fr wt of nodule formation and exhibited the relative activities of 152％ and 162％ for total and specific ARA in comparison with those of control plant grown with N-free for 60 days. Total biomass and ARA was by 70％ and 86％ lower in N and P deficiency, respectively. The N and P deficient plot showed 70％ and 86％ decreases of total biomass and ARA in comparison with those of control. The plant grown with N-free for 20 days after pretreatment with N and P free media for 40 days showed the relative values of 77％, 118％ and 150％, respectively for nodule biomass, total and specific ARA in comparison with those of control. The treatment with acid or alkali gradients resulted in significant decreases of nodule biomass and ARA. The optimum temperature and pO₂for ARA were 30°C and 40 kPa, respectively. Two peaks of diurnal variation appeared at 11:00 and 23:00 o'clocks by the continuous light condition. The plants with water stress by temporary wilting point rsulted in 95~97％ inhibition for nodule respiration, transpiration and specific ARA. Transpiration and ARA ware recovered to 88％ and 38％ of those of water unstressed plants, respectively, 6 hours after the plants were rewatered from water stressed condition.

• The Korean Journal of Ecology
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• 제15권4호
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• pp.377-386
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• 1992

Seasonal changes of symbiotic nitrogen-fixation activity and growth characteristics of four different natural populations of kummerowia striata were quantitatively analyzed during the growing period. the nitrogen-fixation activity of root nodules attained the maximum rates of 148, 132, 102 and 100$\muM\;C_2H_4\;\cdot\;g\;fw\;nodule^{-1}\;\cdot\;hr^{-1}$, respectively for sunny, multibranched, shade and unibranched populations at the optimum growth conditions. and the seasonal changes showed fluctuations by environmental conditions such as light, temperature, nutrient contents, water stress and plant ages, etc. The multibranched plant showed the greater amount of leaf and root nodule biomass, and the higher nitrogenase activity than the unibranched plant. the optimum conditions of leaf chloropht11 and water content of each organ indicated the active growth and the maximum fresh biomass of 4 different populations were 1.92, 1.85, 0.97 and 0.56 g $fw\cdotplant^{-1}$ for shade multibranched, sunny and unibranched populations, respectively.