• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.489-495
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• 2000

When microorganisms such as bacteria and fungi are injected into porous medium such as soils along with appropriate substrate and nutrients, biomass retained in the soil pore. Soil pore size and shape are varied from the initial condition as a result of biofilm formation, which make hydraulic conductivity reduced. In this research, hydraulic conductivity reduction was measured after microorganism are inoculated and cultured with synthetic substrates and nutrients. Biomass-soil mixture was evaluated its applicability to the field condition as an alternative liner material in landfill by measuring hydraulic conductivity change after repetitive freeze-thaw cycles.

• Journal of Microbiology and Biotechnology
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• 제27권12호
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• pp.2180-2189
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• 2017

Psychrophilic phytases suitable for aquaculture are rare. In this study, a phytase of the histidine acid phosphatase (HAP) family was identified in Morchella importuna, a psychrophilic mushroom. The phytase showed 38% identity with Aspergillus niger PhyB, which was the closest hit. The M. importuna phytase was overexpressed in Pichia pastoris, purified, and characterized. The phytase had an optimum temperature at $25^{\circ}C$, which is the lowest among all the known phytases to our best knowledge. The optimum pH (6.5) is higher than most of the known HAP phytases, which is fit for the weak acidic condition in fish gut. At the optimum pH and temperature, MiPhyA showed the maximum activity level ($2,384.6{\pm}90.4{\mu}mol{\cdot}min^{-1}{\cdot}mg^{-1}$, suggesting that the enzyme possesses a higher activity level over many known phytases at low temperatures. The phytate-degrading efficacy was tested on three common feed materials (soybean meal/rapeseed meal/corn meal) and was compared with the well-known phytases of Escherichia coli and A. niger. When using the same amount of activity units, MiPhyA could yield at least $3{\times}$ more inorganic phosphate than the two reference phytases. When using the same weight of protein, MiPhyA could yield at least $5{\times}$ more inorganic phosphate than the other two. Since it could degrade phytate in feed materials efficiently under low temperature and weak acidic conditions, which are common for aquacultural application, MiPhyA might be a promising candidate as a feed additive enzyme.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권3호
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• pp.172-177
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• 2022

Two unrecorded fungi, Diaporthe perseae and Fusarium falciforme, were isolated from soil sampled from Dokdo in Korea. There have been many reports of Diaporthe sp. and Fusarium sp. in mainland Korea but none of them have reported in Dokdo so far. We used the morphological features and two molecular markers including the internal transcribed spacer and translation elongation factor 1-α region to compare and analyze these species with the closely related taxa. As a result, we confirmed that these fungi were unrecorded soil fungi in Korea. Then, the cultural and morphological characteristics such as the conidia of these two fungal species could be clarified. These results are expected to help us to understand the distribution of fungi in Dokdo and manage the Dokdo Island Natural Reserve.

• Mycobiology
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• 제29권2호
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• pp.90-95
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• 2001

During the study of microbial structures in root-regions of tomato and red pepper from fields, various soil-inhabiting fungi were isolated with the dilution plate technique. Among them an ascomycete, Emericellopsis mirabilis and three hyphomycetes, Gliocladium solani, Humicola veronae and Verticillium chlamydosporium are presented for the first time in Korea along with Talaromyces trachyspermus, Chaetomium globosum and Doratomyces microsporus.

• Mycobiology
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• 제36권1호
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• pp.1-9
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• 2008

Sixty three species and 5 varieties belonging to 30 fungal genera were collected from 75 soil samples. Cultivated (29 genera and 58 species + 5 var.), desert (22 and 35 + 2 var.) and saline soil (21 and 41 + 1 var.) fungi were recovered on glucose-, cellulose- and 50% sucrose-Czapek's agar at $28^{\circ}C$. The most common genera were Alternaria, Aspergillus, Emerieella, Fusarium, Mycosphaerella, Nectria and Penicillium. The most prevalent species from the three types of soils on the three types of media were Alternaria alternata, Aspergillus flavus, A. fumigatus, A. niger, A. terreus, Emerieella nidulans, Fusarium oxysporum, Myeosphaerella tassiana, Nectria haematococca and Penicillium ehrysogenum. Chaetomium globosum was in the top of fungi in producing endo-$\beta$-1,4-glucanases among the 42 tested isolates obtained from soils on cellulose-Czapek's agar. Maximum production of this enzyme by C. globosum obtained after 6 days of incubation at $30^{\circ}C$ with culture medium containing maltose as a carbon source and ammonium nitrate as a nitrogen source and pH initially adjusted to 6.

• Mycobiology
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• 제31권1호
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• pp.9-18
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• 2003

A total of 82 genera and 271 species of soil-inhabiting fungi including saprobic, nematode-trapping, and arbuscular mycorrhizal but plant pathogenic fungi published hitherto in South Korea are listed with the information on geographic location, habitat, vegetation when available, and relevant literatures.

• 한국응용곤충학회지
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• 제34권4호
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• pp.368-372
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• 1995

곤충병원성 사상균을 이용한 솔잎혹파리의 효과적인 방제법을 개발하기 위하여, 병원성이 강한 균주를 전국 산림토양으로 부터 분리.동정하고, 병원성 검정을 통하여 유효 곤충병원 사상균을 선발코자 하였다. 솔잎혹파리 다발 지역을 중심으로 전국으로 부터 233개 지역의 토양시료를 채취하여, Beauverla속 29균주, Paecilomyces속 2균주를 분리하였다. 분리된 균주는 위상차현미경 및 주사전자현미경으로 형태를 관찰하였다. 아울러 토양 분리 균주를 솔잎혹파리 유충에 대해 병원성을 검정한 결과, Beauveria 속 SFB-168-2가 82.9%로 높은 병원성을 나타내어, 솔잎혹파리 방제를 위한 유효병원 사상균으로 선발하였다.

• 한국유기농업학회지
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• 제31권1호
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• pp.95-106
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• 2023

본 논문에서는 국내 산림 지역의 토양에서 서식하는 곤충병원성 진균을 insect-baiting 방법을 이용하여 분리하고자 하였으며, 곤충병원성 진균과 토양의 물리적, 화학적 특성과의 관계를 분석하고자 하였다. 국내 산림 지역 5곳을 선정하여 토양을 채집하였으며, 채집된 토양에서 총 42 분리주를 분리하였다. 그 중 Beauveria bassiana (42.9%)와 Metarhizium anisopliae (45.2%)가 주로 분리되었으며, 특히 M. anisopliae의 분포는 토양의 총 질소량(g/kg)과 유기물 함량(%)에 따라 달라지는 것이 확인되었다. 국내 산림 지역의 토양은 낮은 pH를 보였으며(pH 4-5), 전체 분리주 중에서 미사질 양토(silt loam)에서 50% 이상이 분리되었다. 본 연구의 결과는 통하여 토양의 물리적, 화학적 특성과 곤충병원성 진균의 분포 및 다양성과의 관계를 이해하는데 도움이 될 것으로 판단된다.

• Food Science and Biotechnology
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• 제18권4호
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• pp.1038-1041
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• 2009

Aflatoxins are secondary metabolites produced by the aflatoxigenic fungi in suitable conditions. Saffron, Crocus sativus, is the most expensive spice in the world. Saffron is normally contaminated with soil and hand microflora during harvest and post-harvest operations. In this study, rapid assessment of aflatoxigenic fungi in saffron was accomplished using polymerase chain reaction. In total, 37 market samples were assayed in order to isolate aflatoxin-producing fungi. The 18.9% of the total samples were contaminated with aflatoxigenic fungi. Our results also show that most of the isolated fungi were saprophytes which are normally originated from soil during harvest and postharvest process.

• 한국균학회지
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• 제29권2호
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• pp.123-126
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• 2001

국내 남부지역의 논, 밭, 산, 시설재배지 토양 총 43점에서 선충잡이곰팡이를 조사하여, 9종의 포식성곰팡이와 2종의 기생성곰팡이를 분리하였다. 논 토양에서는 1종이 분리되어 선충잡이곰팡이의 검출률이 가장 낮았고(17%), 산에서는 38%의 검출율을 보여 두 번째였으며, 밭과 시설재배지에서는 거의 100% 선충잡이곰팡이가 검출되었다. 우점종은 Arthrobotrys oligospora로 국내 토양 4곳 중 1곳에 서식하며, 시설재배지 토양에서는 2곳 중 1곳에 서식하고 있었다. 선충잡이 도구 중에서는 끈끈이그물(Adhesive nets)을 이용하여 선충을 포식하는 종류가 전체의 72.5%로 가장 많았으며, 다음은 수축성올가미를 가진 A. dactyloides (10.0%), 끈끈이균사를 가진 Cystopage lateralis 7.8%, 내부기생성곰팡이 5.0%, 끈끈이봉을 가진 Monacrosporium ellipsosporum 4.8% 순이었다. 선충잡이곰팡이의 종이나 밀도는 서식 지역에 따라 다르며 토양이 비옥한 시설재배지 토양에서 선충잡이곰팡이의 종과 밀도가 높은 경향이었다.