• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.211-214
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• 2004

MTBE로 오염된 토양에서 생태독성학적 접근 방법으로 3가지 토양 효소의 활성도를 측정해 보았다. MTBE의 잠재적 위험성으로 인한 논란은 계속되고 있으나 토양 오염에 대한 지표로써 토양 효소 활성도의 사용타당성 여부에 대한 실험은 이전에 행해지지 않았다. 따라서 중금속 오염 토양에 대해 좋은 지표로 사용되고 있는 토양 미생물 효소의 활성도를 MTBE에 적용하여 실험해 보았다. 사용한 토양 효소는 Acid Phosphotase, $\beta$-Glucosidase 그리고 Arysulfatase였다. 그러나 실험 결과 MTBE로 오염된 토양의 경우 중금속으로 오염된 토양에 비해 토양 미생물 활성도의 감소가 매우 적었다. 따라서 MTBE의 오염 토양의 경우 본 연구에서 측정된 효소의 활성도는 좋은 지표로 적합하지 않다는 것을 확인했다.

• Journal of Wetlands Research
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• v.14 no.1
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• pp.47-57
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• 2012

We have measured soil enzyme activities, which represent the rates of organic matter decomposition, in four riparian ecosystems in Korea. ${\beta}$-glucosidase, N-acetylglucosaminidase, phosphatase and arylsulfatase activities were determined in five occasions over a year period in soils of control plots and plots with invasive plants, namely Sicyos angulatus and Humulus japonicus. Significantly higher enzyme activities were found in soils with invasive plant in barren land, but the difference was season and enzyme-specific. Although it was not universal changes, the invasive plants appeared to accelerate organic matter decomposition in some disturbed riparian ecosystems.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.307-316
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• 2009

Soil microbial activity and diversity are affected by organic sources applied to improve soil quality and fluctuate seasonally. We investigated the effects of municipal compost (MC), poultry litter (PL), and cover crops of spring oats and red clover (RC) on soil enzyme activities, and soil bacterial community-level physiological profiling (CLPP) in a Mexico silt loam in North Central Missouri, USA. Temporal patterns of these parameters were observed by periodic five soil sampling from spring to fall over a two year period. MC increased soil dehydrogenase (DH) activity consistently beginning about three months after MC application; fluorescein diacetate (FDA) hydrolytic activity significantly began to increase by the September of the first year but fluctuated during the following period. DH activity responded more directly to the amount or properties of organic residues in soils while FDA hydrolysis and CLPP were generally influenced by composition of organic sources, and enzyme activities and CLPP showed seasonal variation, which depended on organic sources and soil moisture. MC and cover crops may be useful organic sources for enhancing general soil microbial activity and altering soil microbial diversity, respectively. Because microbial activities and diversity are dynamic and subject to seasonal changes, the effects of organic amendments on these parameters should be investigated frequently during a growing season.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.518.2-519
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• 1986

토양으로부터 분리한 질소고정균인 Klebsiella pneumoniae NFB320의 chromosomal DNA를 BamHI으로 절단하여 동일한 제한효소로 절단한 pBR322에 ligation시켜 E. coli HB101에 형질전환을 행하여 pullulanase activity를 나타내는 clone을 얻어내었다. 이 형질 전환체로부터 분리한 pullulanase 유전자가 재조합된 plasmid DNA는 약 10kb의 DNA단편을 가지고 있었으며, 재조합된 plasmid로부터 생산되는 pullulanase의 특성은 최적 활성 pH가 6.0이며, 효소의 pH안정성은 5-10이었다. 또한 형질 전환체로부터 생산되는 pullulanase의 localization,효소활성에 영향을 미치는 온도안정성 둥을 조사하였다.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.234-241
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• 2007

Biological amendments consisting of suspensions of selected microorganisms are often used in conjunction with various organic materials for amending soils to improve soil quality and plant growth. The effects of the biological amendment on chemical and biological properties of soil were investigated for a biological amendmentalone and when combined with different organic materials includingmunicipal compost (MC), poultry litter (PL), and cover crops (red clover (RC) and spring oats). A liquid preparation of a biological amendment called Effective Microorganisms was sprayed on the tested plots three times over a two-year period. Effective Microorganisms alone did not influence pH, K, or organic matter content in soil. However, increases in P in PL-treated soils in fall of both years andCa in MC-treated soil in fall 2001, and decreases in Ca, Mg, and cation exchange capacity (CEC) in RC-planted soil were associated with EM. Increased dehydrogenase(DH) activitiesassociated with Effective Microorganismswere only detected in July (P=0.0222) and October (P=0.0834) for RC-planted soils in the first year. Fluorescein diacetate (FDA) hydrolysisappeared to be enhanced by Effective Microorganisms in soils untreated or treated with MC and oatsbut only sporadically during the sampling period. FDA hydrolysis in both PL- and RC-treated soils as well as DH activity in PL-treated soils decreased with Effective Microorganisms treatment. Effective Microorganisms did not influence substrate utilization patterns expressed by the BIOLOG assay. We conclude that Effective Microorganisms effects on soil chemical and biological properties varied depending on the added organic materials. Effective Microorganisms periodically increased soil DH activity and FDA hydrolysis with RC and with MC plus oats, respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2132-2137
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• 2009

갈대(Phragmites communis Trin.)란 염분이 있는 곳에서 자라는 염생식물로서 우리나라 전역에 분포하고 있다. 지난 50년 동안 우리나라의 여러 습지에 걸쳐서 갈대는 우점종으로 자라왔고, 육지와 수중서식지에서 갈대의 확산범위는 증가하고 있다. 갈대의 확산은 다른 습지 식물의 서식지를 파괴하고, 갈대가 번식하면 동 식물들의 번식 자체가 어려울 뿐 아니라 갈대숲에 포식자가 늘어나 살아가기 어려운 환경으로 변하기때문에 갈대를 체계적으로 관리할 수 있는 방안이 마련되어야 한다. 본 연구는 우점종이 다른 두 습지에서 갈대군집의 성장률을 관찰하고, 토양의 화학적 분석과 식물의 생리적 분석을 통해 갈대군집 성장에 미치는 영양염류의 영향을 규명하였다. 연구 대상지는 한강하구에 위치한 장항습지와 성동습지로서 동일하게 갈대가 분포하며, 장항습지에는 줄 군락이 성동습지에는 새섬매자기 군락이 우점하고 있다. 분석 항목은 이화학적 항목을 비롯하여 용존유기탄소(DOC, dissolved organic carbon), 체외미생물효소활성도(Extracellular enzyme activities), 암모니아성 질소($NH_4^+$), 질산성 질소($NO_3^-$)을 분석하였다. 실험결과, 두 습지 갈대의 성장은 7월부터 9월에 증가하였고 성동습지의 토양성분이 점토질로 형성되어 높은 수분함량과 유기물함량을 유지하고 있기 때문에 갈대의 밀도가 높고 성장률이 활발한 것으로 나타났다. 또한 미생물활성과 환경인자간 양의 상관관계를 보아 환경인자들이 미생물 활성을 자극하고 미생물들은 식물의 성장을 촉진하여 영향을 주며, 반면 식물 뿌리는 enzyme을 생성하는 미생물에게 C 삼출물을 공급해 enzyme 활성에 영향을 미칠 것으로 사료된다.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.04a
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• pp.98.5-99
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• 1978

항생물질과 RNA 분해효소를 동시에 생산하는 방선균의 한 균주를 토양으로부터 분리하여 이 균주가 생산하는 RNA 분해효소의 물리화학적 성질 및 분해산물에 대해 검토하였다. 효소반응의 최적 pH 및 온도는 명명 pH 5.6과 $50^{\circ}C이었다.$ $37^{\circ}C$ 에서 90분간 열처리 시켰을 때, 이 효소의 활성은 비교적 안정하였지마는 $50^{\circ}C$ 에서 90분간 열처리 시켰을 때는 효소활성이 심하게 저하되었다. 이 효소의 활성은 $Ba^{2+}$ 에 의하여 50% 정도의 저해 작용을 나타내었지만 EDTA에 의해서는 저해되지 않았다. 이 효소에 의한 RNA분해로 이 효소가 대사산물로서 guanosine, adenosine과 밝혀지지 않은 두 가지의 핵산관연물질을 생산함을 알 수 있었다. 제2보에서는 ENase의 효소학적 성질을 검토하였으며 이후 항생물질 측면에서 검토할 예정이다.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.105-110
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• 1985

A incubation study was conducted to find out the effects of rice straw and gypsum as soil ameriolite on urease, nitrate and nitrite reductase activities in newly reclaimed saline sandy soil. The results obtained were summarized as follows: 1. Very low urease activities were observed in saline soil if contrast to high productive paddy soil. Urease activities were lower at 5 days than that of 25 and 50 days after incubation. Remarkably high urease activities were obtained by the application of rice straw and gypsum. 2. Comparing with NPK treatment, application of rice straw and gypsum were enhanced the activities of nitrate and nitraite reductase. 3. Positive correlation (r=0.5501 p=0.05) was obtained between urease activities and ammonium nitrogen concentration in soil. 4. Cyclic oxidation and reduction of nitrate and nitrite in soil were obtained in terms of first order microbial kinetics reaction in case of application of rice straw and gypsum, respectively. 5. Positive correlation (r=0.6296 p=0.05) was obtained between the activitie of nitrite reductase and nitrate reductase in soil.

• Journal of Korea Soil Environment Society
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• v.4 no.1
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• pp.13-23
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• 1999

In this research, 3-hydroxypyridine(2-HP) metabolic ability of starving Arthrobacter crystallopoietes cell and the effect of humic acid on the metabolism of this starving cell were evaluated. 2-HP metabolic ability of exponential phase cell (acclimated cell) was much higher than that of lag phase cell (unacclimated cell) during starvation period. After 3 days of starvation, 2-HP half-life of the acclimated cell was 14 hours and that of the unacclimated cell was 46.5 hours. Humic acid enhanced the stability of 2-HP monooxygenase of starving co]1 and, after 2 days of starvation, the residual activity rate of this enzyme of the microbial cell starved in humic acid solution was 12% while the rate for control condition was 1.5%. After 14 days of starvation, 2-HP half-life for control condition was 43 hours and that for humic acid condition was 1.25 hour.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.139-143
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• 2002

To find $\alpha$-glucosidase inhibitors produced by Actinomycetes, bacteria belonging to Actinomycetes were isolated from soil sample using Bennett's medium. The inhibitory activity induced by these bacteria on $\alpha$-glucosidase, which is the key enzymes far carbohydrates digestion and the prevention of diabetic complications, was investigated. A strain of these bacteria, PM718 potently inhibited $\alpha$-glucosidase activity in vitro.