• Korean Journal of Soil Science and Fertilizer
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• v.8 no.4
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• pp.171-176
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• 1975

The rate and extent of decomposition of rice straw and compost in an acid sulfate soil amended with urea and lime and incubated under aerobic and anaerobic(flooded) conditions were investigated in the laboratory. Results are summarized as follows: 1. The rate of compost(alone) decomposition in a flooded soil was more than twice as high as all other treatments, which included rice straw+urea, rice straw+lime, rice straw (alone), and compost+lime. Lime appeared to suppress the decomposition of compost in a flooded soil but actually enhanced its decomposition under aerobic conditions. 2. Compost decomposition in both anaerobic and aerobic environments was characterized by single maximum peak rates of $CO_2$ evolution that were reached soon after the start of incubation. 3. Both urea and lime greatly increased the rate and extent of rice straw decomposition in the soil when incubated aerobically, although urea had a greater effect than did liming. Decomposition rates were characterized by the appearance of two maximum peak rates, a greater primary peak and a smaller secondary peak. 4. The percent decomposition of rice straw in soil incubated aerobically was approximately half (10.8%) that of compost(23.1%). However, percent decomposition of these substrates in soil amended with lime was essentially the same; i.e., rice straw+lime (29.4%) and compost+lime(31.6%). 5. There is a need to investigate the possible interaction between the addition of lime (pH) and supplemental nitrogen applied to acid sulfate soils and how this interaction might affect the decomposition of organic wastes and residues.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.949-957
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• 2000

This study investigates the remediation of the phenol or PNP(p-Nitrophenol) contaminated soils in a slurry reactor by a pure culture, P-99. The application of a pure culture for the phenol decontamination make the degradation rate three times faster than that of the mixed activated sludge. The destruction of 300 mg/L phenol was completed in 26 hours. As 1 mg of phenol was added, 0.1457 mg of microorganism was grown in the medium. The pure culture could not utilizes PNP, one of the xenobiotics, as a growth substrate. When the bacteria was induced by phenol enrichment medium. PNP could be effectively transformed with cometabolic process. The induction of the bacteria requires 1 mg of phenol for the destruction of 0.027 mg PNP. When PNP concentration in the medium contained phenol and PNP increased. the degradation rate of phenol was decreased. The degradation rate of phenol and PNP in the slurry reactor was about two times faster than in the reactor without slurry because of higher dissolved oxygen supply in the aqueous phase and adsorption on the surface of the soil.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.304-314
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• 2010

This study was carried out to find out potential use of ochre as an agent to reduce phosphorus content in water. Ochre is a by-product from treatment of acid mine drainage (AMD) which is composed mostly of $Fe_2O_3$, $Fe_2O_3{\cdot}H_2O$, $FeO{\cdot}OH$ and $Fe(OH)_3$. Three ochre samples (ochre-H, ochre-D and ochre-S) were collected from three treatment facilities in Gangwon province. Physico-chemical characteristics of three ochre samples including pH, electrical conductivity, total phosphorus, available phosphorus, particle size distribution were analyzed. Scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis were also carried out. In addition, experiments for phosphorus removal from water was performed. Calcium content of ochre-H was higher than that of ochre-D and ochre-S, whereas iron content of ochre-H was lower than that of ochre-D and ochre-S. All the phosphorus in water up to maximum 191,411 mg $kg^{-1}$ per unit mass of ochre was removed with ochre-H. Ochre has immense potential as an agent to reduce phosphorus content in water.

• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.217-227
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• 2006

Micronutrient status in soils and crops of plastic film house and their relationship were investigated. Total 203 plastic film houses were selected (red pepper, 66; cucumber, 63; tomato, 74) in Yeongnam region and soil and leaf samples were collected. Hot-water extractable B and 0.1 N HCl extractable Cu, Zn, Fe, and Mn in soil samples and total micronutrients in leaf samples were analyzed. Contents Zn, Fe, and Mn in most of the investigated soils were higher than the upper limits of optimum level for general crop cultivation. Contents of Cu in most soils of cucumber and tomato cultivation were higher than the upper limit of optimum level, but Cu contents in about 30% of red pepper cultivation soils were below the sufficient level. Contents of B in most soils of cucumber and tomato were above the sufficient level but in 48% of red pepper cultivation soils B were found to be deficient. Micronutrient contents in leaf of investigated crops were much variable. Contents of B, Fe, and Mn were mostly within the sufficient levels, while in 71% of red pepper samples Cu was under deficient level and in 44% of cucumber samples Cu contents were higher than the upper limit of sufficient level. Contents of Zn in red pepper and cucumber samples were mostly within the sufficient level but in 62% of tomato samples Zn contents were under deficient condition. However, any visible deficiency or toxicity symptoms of micronutrients were not found in the crops. No consistent relationships were found between micronutrient contents in soil and leaf, and this indicates that growth and absorption activity of root and interactions among the nutrients in soil might be important factors in overall micronutrient uptake of crops. For best management of micronutrients in plastic film house, much attention should be focused on the management of soil and plant characteristics which control the micronutrient uptake of crops.

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.603-613
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• 2019

This study was carried out to examine the antagonistic effect against phytopathogenic fungi of isolated strains from soil samples collected from Busan, Changwon, and Jeju Island: Botrytis cinerea, Colletotrichum acutatum, Corynespora cassiicola, Fusarium sp., Rhizoctonia solani, Phytophthora capsici, and Sclerotinia sclerotiorum. According to results of our studies, isolated strains showed an antagonistic effect against phytopathogenic fungi. Such an antagonistic effect against phytopathogenic fungi is seen due to the production of siderophores, antibiotic substances, and extracellular amylase, cellulase, protease, and xylanase enzyme activities. Extracellular enzymes produced by isolated strains were significant, given that they inhibited the growth of phytopathogenic fungi by causing bacteriolysis of the cell wall of plant pathogenic fungi. This is essential to break down the cell wall of plant pathogenic fungi and thus help plant growth by converting macromolecules, which cannot be used by the plant for growth, into small molecules. In addition, they are putative candidates as biological agents to promote plant growth and inhibit growth of phytopathogenic fungi through nitrogen fixation, indole-3-acetic acid production, siderophore production, and extracellular enzyme activity. Therefore, this study suggests the possibility of using Bacillus subtilis ANGa5, Bacillus aerius ANGa25, and Bacillus methylotrophicus ANGa27 as new biological agents, and it is considered that further studies are necessary to prove their effect as novel biological agents by standardization of formulation and optimization of selected effective microorganisms, determination of their preservation period, and crop cultivation tests.

• Journal of the Korean Society of Groundwater Environment
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• v.3 no.2
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• pp.70-79
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• 1996

The Friar Tuck Abandoned Coal Mine site is one of the most complexly disturbed areas in the midwestern United States. The deposits of gob and tailings contain high concentrations of pyrite, whose oxidation contributes to the acidification of soil and water and prevents the growth of vegetation. In an effort to quantitatively evaluate the effects of reclamation techniques, detailed monitoring program was performed. Water samples were collected from surface water, groundwater, and pore water from the unsaturated zone during a period of five years. According to the results, The spoil deposits are a relatively minor source of contamination and gob piles are the source of severe contamination to surface water and groundwater. But, loess and till beneath the gob piles effectively prevent the contaminated water migration from the source. Surface layers of the gob piles and the tailing deposits are less toxic than the interior of the deposits as a consequence of weathering over several decades. Acid mine drainage is in a post-peak stage and acid formation potential is probably situated in the unsaturated zone of refuse.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.49-56
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• 2003

The strain Ralstonia eutopha JMP134 (formerly Alcaligenes eutrophus JMP134) can degrade trichloroethylene(TCE) through a chromosomal phenol-dependent pathway. The phenol hydroxylase was previously found to be a single responsible enzyme for TEC degradation. Here, we demonstrate that a recombinant bacterium, R. eutopha AEK301, one of Tn5-induced mutants of JMP134 containing a recombinant plasmid pYK3011, degrades TCE in the absence of inducer, phenol and in the presence of various carbon sources. Complete removal of TCE ($50{\mu}M$) was observed in minimal medium containing only 0.05% ethanol as a carbon source within 24 hours. The bacterium removed $200{\mu}M$ of TCE to below detectable level within two days under non-selective pressure. When TCE concentration was increased up to $400{\mu}M$, the degradation had been continued until two days, then ceased with removal of 70% of detectable TCE.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1415-1419
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• 2006

메탄을 탄소원 및 에너지원으로 이용하는 메탄산화균은 물질대사과정 중에 다량의 세포외 고분자물질인 Extracellular polymeric substances(EPS)를 생성하는데, EPS는 카르복실기와 같은 표면흡착 기능을 가지고 있어 생체흡착제로 사용이 가능하다. 따라서 본 연구에서는 메탄산화세균을 이용하여 중금속인 Cd의 흡착성능을 파악하여 활성슬러지의 흡착능과 비교하고, EPS 농도별, pH별 흡착량의 변화를 실험한 후 Freundlich 흡착모델식에 적용하여 흡착공정의 기본적인 설계인자를 도출하고자 하였다. 실험에 사용한 메탄산화세균은 매립지 복토층 상부 토양에서 분리하여 실험실에서 대량으로 배양하였으며, EPS 생성을 위해 메탄을 Head space의 20%를 주입하고 $30^{\circ}C$, 150rpm에서 질소원이 부족한 조건으로 48hr 동안 배양하였다. Cd의 흡착실험은 용액의 pH를 3에서 8까지 변화를 주면서 활성슬러지와 메탄산화세균의 시간별 흡착능을 측정하였다. 또한 중금속의 농도별 흡착능을 측정하여 흡착평형 상수를 파악하였으며, 중금속 흡착 전, 후 미생물의 SEM 촬영, FT-IR 분석, 전자현미분석(EPMA)을 통하여 무기성분 분석 및 표면관찰을 수행하였다. 실험결과 메탄산화세균에 의해 생성된 EPS 물질은 중금속에 대한 강한 결합능력이 있으며, Cd에 대한 최고 흡착능은 26mg Cd(Ⅱ)/g VSS의 값을 보였다. 이러한 미생물의 EPS의 흡착능은 pH와 칼슘이온의 영향을 많이 받았으며, 메탄산화세균의 FT-IR 분석결과 EPS에는 sulfate ester, pyruvate 등과 같은 작용기와 amino sugar, carboxyl 작용기들이 많이 존재하여 활성슬러지에 비해 중금속의 흡착능이 높은 것으로 사료되었다.X>${\mu}_{max,A}$는 최대암모니아 섭취률을 이용하여 구한 결과 $0.65d^{-1}$로 나타났다.EX>$60%{\sim}87%$가 수심 10m 이내에 분포하였고, 녹조강과 남조강이 우점하는 하절기에는 5m 이내에 주로 분포하였다. 취수탑 지점의 수심이 연중 $25{\sim}35m$를 유지하는 H호의 경우 간헐식 폭기장치를 가동하는 기간은 물론 그 외 기간에도 취수구의 심도를 표층 10m 이하로 유지 할 경우 전체 조류 유입량을 60% 이상 저감할 수 있을 것으로 조사되었다.심볼 및 색채 디자인 등의 작업이 수반되어야 하며, 이들을 고려한 인터넷용 GIS기본도를 신규 제작한다. 상습침수지구와 관련된 각종 GIS데이타와 각 기관이 보유하고 있는 공공정보 가운데 공간정보와 연계되어야 하는 자료를 인터넷 GIS를 이용하여 효율적으로 관리하기 위해서는 단계별 구축전략이 필요하다. 따라서 본 논문에서는 인터넷 GIS를 이용하여 상습침수구역관련 정보를 검색, 처리 및 분석할 수 있는 상습침수 구역 종합정보화 시스템을 구축토록 하였다.N, 항목에서 보 상류가 높게 나타났으나, 철거되지 않은 검전보나 안양대교보에 비해 그 차이가 크지 않은 것으로 나타났다.의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전

• Korean Journal of Microbiology
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• v.28 no.2
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• pp.162-168
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• 1990

The aims of the present study were to evaluate the effects of culture conditions on the biosynthesis of extra-cellular alkaline protease in Streptomyces sp. The formation of aerial mycelia and spores were compared with the protease production in order to know the relations between the alkaline protease and the cell differentiation. As results, it was found that substrate concentration was very critical to regulate the formation of the protease, aerial mycelia, and spores, which were resulted from the changes of culture pH to acid. When the culture pH was adjusted with phosphate buffer from pH 6 to pH 9, the alkaline protease production was increased as the culture pH increased whereas aerial mycelia and spore formation were reversely related to the culture pH. Therefore, it was thought that the culture pH was an important factor to regulate the alkaline protease synthesis.

• Korean Journal of Pharmacognosy
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• v.15 no.1
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• pp.15-23
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• 1984

To find antimicrobial strains of the soil microorganisms in Korea, they were isolated from the soil samples of different locations and screened for antibiotic activity against several standard microbes. An isolate among them had an antibacterial activity against gram-positive bacteria. The examination of its morphological and biochemical characteristics according to the International Streptomyces Project methods showed that it belongs to the genus Streptomyces. The strain was named DMC-72. The strain appears to be a new strain when it was compared with the species within the genus which have been so far reported. The antibiotic metabolite of the strain was produced in submerged culture method. It was found to be a quinone compound and was named soulomycin. This strain was also found to produce an ${\alpha}-amylase$ inhibitor in the submerged culture.