• 한국균학회지
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• 제1권1호
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• pp.23-28
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• 1973

The soil of Kwangneung area(Kyeunggi-Do) was inoculated directly into wheat-bran-media and after $3{\sim}4$ days of incubation, a Penicillium species whose cellulase activity was 1011u/g was isolated. With the treatment of mutagenic agents an improved strain(cellulase activity: 1303u/g) was obtained. This strain was screened again by mono-spore isolation method. Finally a strain C8-14 (cellulase activity: 2351u/g) which had lesser spores than the wild strain was obtained.

• Archives of Pharmacal Research
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• 제10권2호
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• pp.103-109
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• 1987

To find microorganisms producing esterase inhibitors, microbes were isolated from soil samples that were collected at different locations in Korea and screened for inhibitory activities. One of the inhibitor-producing strains was named strain DMC-498. This strain was found to be a new species of the genus Streptomyces by comparison with the characteristics of morphology and metabolisms of the other species of the genus.

• 아시안잔디학회지
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• 제25권1호
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• pp.69-72
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• 2011

토양입단화는 토양의 물리적 화학적 그리고 생물학적인 변화를 일으키는 활발한 과정이다. 토양입단화를 통해서 생성된 토양공극은 토양에서 공기와 물의 순환을 증가시키는 역할을 하게 된다. 유기중합물이 토양입단 안정화에 대한 긍정적인 역할은 많은 연구결과에서 보고가 된 바 있다. 본 실험의 목적은 유기중합물이 토양입단화와 페레니얼 라이그래스의 성장에 미치는 영향에 대해서 알아보기 위해서 수행되었다. 유기중합물의 세가지 농도가 적용이 되었으며 실험을 위해 두가지 토양이 사용이 되었다. 첫번째 토양으로 4.0%의 유기물이 함유된 양토가 건조된 후 사용이 되었으며 두번째 토양으로 점토가 사용이 되었다. 유기중합물 처리에 따른 페레니얼 라이그래스의 색, 품질, 성장에 미치는 영향은 나타나지 않았다. 그러나 유기중합물이 토양입단화에는 토양의 종류에 따라 영향이 있는 것으로 나타났다. 본 실험의 결과의 구체적인 실증을 위해서 필드 실험이 필요한 것으로 판단이 된다.

• 한국유기농업학회지
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• 제19권spc호
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• pp.251-254
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• 2011

Botrytis cinerea infects stems and leaves of greenhouse tomatoes and can cause serious economic losses. This study was conducted to develop environment-friendly control method against tomato gray mold. Antagonistic microorganisms (bacteria) were screened for control activity against Botrytis cinerea, both in vitro and in vivo, using stem sections. One hundred bacterial strains were isolated from the rhizospheric soil of various plants including tomato. These strains were screened for growth inhibition of Botrytis cinerea on agar plate by the dual culture and thirty strains showing strongly inhibitory effect against the pathogen were selected first. Among thirty strains, JB 5-12, JB 22-2, JB 22-3, U 4-8 and U46-6 reduced significantly disease incidence, when applied simultaneously with the pathogen. These results suggested that five antagonistic bacteria strains selected have the potential to control tomato gray mold in organic farming.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.587-593
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• 2010

Three hundred and seventy-four rhizobacteria were isolated from the rhizosphere soil (RS) or rhizoplane (RP) of Echinochloa crus-galli, Carex leiorhyncha, Commelina communis, Persicaria lapathifolia, Carex kobomugi, and Equisetum arvense, grown in contaminated soil with petroleum and heavy metals. The isolates were screened for plant growth-promoting trait (PGPT), including indole acetic acid (IAA) productivity, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, and siderophore(s) synthesis ability. IAA production was detected in 86 isolates (23.0%), ACC deaminase activity in 168 isolates (44.9%), and siderophore(s) synthesis in 213 isolates (57.0%). Among the rhizobacteria showing PGPT, 162 isolates had multiple traits showing more than two types of PGPT. The PGPT-possesing rhizobacteria were more abundant in the RP (82%) samples than the RS (75%). There was a negative correlation (-0.656, p<0.05) between the IAA producers and the ACC deaminase producers. Clustering analysis by principal component analysis showed that RP was the most important factor influencing the ecological distribution and physiological characterization of PGPT-possesing rhizobacteria.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권3호
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• pp.27-33
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• 2010

The purpose of this study was in search of native plant species showing metal-resistant property and excessively accumulating heavy metals in metal-contaminated soil or abandoned mines as well as in evaluation of applicability of phytoremediation. In the study area, species showing excessively accumulating heavy metals were a shepherd´s purse, pampas grass, a Korean lettuce, a Hwansam vine, the Korean persicary, a foxtail, a goosefoot, and a water pepper. The first screened plant species in Sambo mine were as shepherd's purse, Korean lettuce and pampas grass Among them the shepherd´s purse can be excluded because it is a seasonal plant and has lower removal capacity for heavy metals. The Korean lettuce was also excluded because of having lower removal capacity for heavy metals. Pampas grass is a highly bionic plant species constantly growing from spring. However it has weak points such as little accumulation capacity for zinc as well as small values of an accumulation factor and a translocation factor. Another problem is regarded as removal of roots after the clean up if pampas grass is applied to a farmland. In Sanyang mine, wormwood and Sorijaengi were considered as adaptable species.

• 생약학회지
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• 제15권1호
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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.

• Journal of Microbiology and Biotechnology
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• 제17권10호
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• pp.1655-1660
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• 2007

A metagenome is a unique resource to search for novel microbial enzymes from the unculturable microorganisms in soil. A forest soil metagenomic library using a fosmid and soil microbial DNA from Gwangneung forest, Korea, was constructed in Escherichia coli and screened to select lipolytic genes. A total of seven unique lipolytic clones were selected by screening of the 31,000-member forest soil metagenome library based on tributyrin hydrolysis. The ORFs for lipolytic activity were subcloned in a high copy number plasmid by screening the secondary shortgun libraries from the seven clones. Since the lipolytic enzymes were well secreted in E. coli into the culture broth, the lipolytic activity of the subclones was confirmed by the hydrolysis of p-nitrophenyl butyrate using culture supernatant. Deduced amino acid sequence analysis of the identified ORFs for lipolytic activity revealed that 4 genes encode hormone-sensitive lipase (HSL) in lipase family IV. Phylogenetic analysis indicated that 4 proteins were clustered with HSL in the database and other metagenomic HSLs. The other 2 genes and 1 gene encode non-heme peroxidase-like enzymes of lipase family V and a GDSL family esterase/lipase in family II, respectively. The gene for the GDSL enzyme is the first description of the enzyme from metagenomic screening.

• 한국지반환경공학회 논문집
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• 제13권3호
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• pp.59-70
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• 2012

본 연구에서는 중금속오염 토양에 대하여 소량의 다양한 안정화제를 이용한 안정화공법과 식물정화증진공법을 동시에 적용하여 식물상 정화공법의 보조단계로 최적의 효과를 가진 안정화제를 알아보고자 하였다. 국내의 비교적 큰 규모의 중금속 오염토양인 제련소 오염토양을 대상으로 zeolite, Mn dioxide, slag, Ca oxide, 및 magnetite를 안정화제로 처리한 후 고사리과 식물을 이용한 식물상 정화증진공법 실험을 진행하였다. 안정화제 사용여부 및 종류에 따른 토양의 중금속 추출율을 확인하였으며, 식물시료의 성장 특성과 중금속 흡수율을 확인하였다. 안정화제 적용 시 토양의 용출율은 감소되었으며 중금속의 안정화가 이루어졌으며, magnetite, calcium oxide등의 안정화제가 좋은 효과를 보였다. 식물시료의 분석결과 Pb, Cu, Zn, 그리고 Ni등의 중금속은 식물의 뿌리 부분에 높은 농도로 농집 되는 것을 확인하였고, As의 경우 잎에 높게 농집 되는 것을 확인하였다. 안정화제를 투입한 결과 식물의 성장이 촉진되어 바이오매스생산량이 증대되었다. 안정화제는 식물상 정화공법이 적용되는 비교적 장기간 동안 토양 내의 중금속의 용출을 막아주며 식물의 성장을 촉진시켜 식물상 정화공법만을 사용할 경우 염려되는 오염의 유출 등의 식물상 정화공법의 단점을 보완해줄 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제17권8호
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• pp.1300-1307
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• 2007

This study assessed the possible role of different traits in selected plant growth-promoting rhizobacteria (PGPR) for improving wheat growth and yield under natural conditions. Rhizobacteria exhibiting 1-aminocyclopropane-1-carboxylate (ACC)-deaminase activity were isolated and screened for their growth-promoting activity in wheat under axenic conditions. Five isolates belonging to Pseudomonas and one Burkholderia caryophylli isolate that showed promising performances under axenic conditions were selected and characterized for in vitro ACC-deaminase activity, chitinase activity, auxin production, P solubilization, and root colonization. These isolates were then used as inocula for wheat cultivated under natural conditions in pot and/or field trials. Significant increases in root elongation, root weight, tillers per pot, 1,000-grain weight, and grain and straw yields were observed in response to inoculation with PGPR in the pot trials. Inoculation with these PGPR was also effective under field conditions and increased the wheat growth and yield significantly. However, the efficacy of the strains was inconsistent under the axenic, pot, and field conditions. Pseudomonas fluorescens ($ACC_{50}$), which exhibited a relatively high in vitro ACC-deaminase activity, chitinase activity, auxin production, and P solubilization and more intensive root colonization, was the most efficient isolate under the field conditions. Therefore, these results demonstrated that ACC-deaminase activity is an efficient parameter for the selection of promising PGPR under axenic conditions. However, additional traits of PGPR, including auxin production, chitinase activity, P solubilization, and root colonization, are also important for selecting PGPR as biofertilizers.