• 한국식물병리학회지
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• 제10권2호
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• pp.144-147
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• 1994

About 450 phytopathogenic fungal cultures were stored in sterile distilled water ar room temperature by the sterile water storage method, which has been known as a simple, convenient, and long-term storage method of microorganisms. After 12 months, viability and pathogenicity of the stored isolates were tested. Among 205 tested, 175 isolates (84.5%) survived. Of these, Rhizoctonia solani, Botrytis cinerea, Pyricularia oryzae, Phytophthora infestans, and Sclerotinia sclerotiorum showed relatively lower survival rate; 92%, 74.1%, 62.5%, 45.8%, and 30%, respectively. Twenty seven isolates belonging to seven important phytopathogenic fungi were tested for pathogenicity, and all isolates tested maintained pathogenicity until at least 12 months after storage.

• Mycobiology
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• 제49권1호
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• pp.69-77
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• 2021

The application of antagonistic fungi for plant protection has attracted considerable interest because they may potentially replace the use of chemical pesticides. Antipathogenic activities confirmed in volatile organic compounds (VOCs) from microorganisms have potential to serve as biocontrol agents against pre- and post-harvest diseases. In the present study, we investigated Galactomyces fungi isolated from rotten leaves and the rhizosphere of cherry tomato (Lycopersicon esculentum var. cerasiforme). VOCs produced by Galactomyces fungi negatively affected the growth of phytopathogenic fungi and the survival of nematodes. Mycelial growths of all nine examined phytopathogenic fungi were inhibited on agar plate, although the inhibition was more intense in Athelia rolfsii JYC2163 and Cladosporium cladosporioides JYC2144 and relatively moderate in Fusarium sp. JYC2145. VOCs also efficiently suppressed the spore germination and mycelial growth of A. rolfsii JYC2163 on tomatoes. The soil nematode Caenorhabditis elegans exhibited higher mortality in 24 h in the presence of VOCs. These results suggest the broad-spectrum activity of Galactomyces fungi against various plant pathogens and the potential to use VOCs from Galactomyces as biocontrol agents.

• 생명과학회지
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• 제20권3호
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• pp.403-410
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• 2010

고품질의 발효퇴비를 생산할 목적으로 자연계로부터 효소활성이 높고 식물병원성 균주에 대한 항균활성이 우수한 미생물을 순수분리 하여 배양학적 특성을 검토하였다. 부엽토 등으로부터 CMCase, protease 및 chitinase 활성이 높고 식물병원성 균주에 대하여 항균활성이 우수한 KJ-9균주를 분리한 다음 형태학적 및 생화학적 특성을 검토하고 Bergey's Mannual of Systematic Bacteriology의 방법과 ATB (Automated Identification) computer system (Bio Merieux, France)을 이용한 API 50 CHL Carbohydrate Test Kit(Bio Merieux, France)를 통하여 동정한 결과 Bacillus licheniformis로 밝혀졌다. B. licheniformis KJ-9의 최적배지 성분을 검토한 결과 탄소원은 1.5% soluble starch, 질소원은 0.5% yeast extract, 무기염은 0.05% $MgSO_4{\cdot}7H_2O$ 이었으며, 배지의 초기 pH는 7.0, 배양온도는 $50^{\circ}C$ 그리고 진탕속도는 180 rpm으로 밝혀졌다. 최적배양 조건으로 B. licheniformis KJ-9를 배양하였을 때 36~60 hr째의 배양액은 잿빛 곰팡이병을 유발하는 Botrytis cinerea, 잎마름병의 원인균인 Corynespora cassicola, 시들음병을 유발하는 Fusarium oxysporum, 잘록병의 원인균인 Rhizocfonia solani의 식물병원성 미생물 균사생장을 효과적으로 억제하였다.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.603-613
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• 2019

본 연구에서 부산, 창원, 제주도 일대에서 채취한 토양으로부터 분리한 균주를 이용하여 식물 병원성 곰팡이에 대해서 길항작용을 나타내는 것을 확인하였으며, 또한 분리 균주의 경우 세균성 균주에 대해서도 길항작용을 나타내는 것을 확인하였다. 이러한 길항작용은 Bacillus 속이 생산하는 2차 대사산물인 siderophore, 항생물질, 세포 외 효소 활성 등에 의해서 식물 병원성 곰팡이에 대한 길항작용을 나타내는 것으로 보이며, 특히 분리 균주로부터 생산되는 세포 외 효소는 식물 병원성 곰팡이의 세포벽에 용균작용 일으킴에 따라 세포벽을 분해하여 식물 병원성 곰팡이의 생장을 저해할 것으로 생각된다. 또한 질소 고정능 및 IAA 생성능을 통해 식물 생장 촉진 및 식물 병원성 곰팡이 성장을 억제시킬 수 있는 생물학적 제제로서 식물재배에 도움을 줄 것으로 기대된다. 최종 선별된 Bacillus subtilis ANGa5, Bacillus aerius ANGa25, Bacillus methylotrophicus ANGa27를 이용하여 식물 병원성 곰팡이 방제 및 식물 생장촉진활성을 가지는 새로운 생물학적 제제로서 이용 가능성을 제시한다.

• 한국약용작물학회지
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• 제28권1호
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• pp.38-46
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• 2020

Background: Although Sancho (Zanthoxylum schinifolium Siebold & Zucc) oil has traditionally been used for its antibiotics properties, there is currently a lack of scientific evidence regarding its biological activities. In this study, we investigated the antimicrobial and antioxidant activities of Sancho oil against food-hazardous microorganisms, phytopathogens, and dermatophytes. Methods and Results: We investiated the antimicrobial activity of Sancho oil against 11 food-hazardous microorganisms, nine phytopathogens, and six dermatophytes. The Sancho oil was found to show the strongest antibacterial activity against Shigella flexneri and Listeria spp. Sancho oil also showed high antifungal activity against plant pathogens, particularly Fusarium oxysporum, and showed antimicrobial activity against dermatophytes such as Trichophyton rubrum, Microsporum canis and Candida albicans. The antioxidant activity of Sancho oil was measured using the DPPH method, and was found to be stronger than that of unrefined oil. Moreover, this activity increased with increasing oil concentration. Conclusions: We found that Sancho oil showed differing antimicrobial activities against food-hazardous microorganisms, dermatophytes, and plant pathogens. The antimicrobial activity spectrum of Sancho oil was not broad and varied among microbial strains. On the basis of our findings, we consider that Sancho oil could be used an antibacterial material for food-borne S. flexneri and Listeria spp., a biopesticide for Fusarium spp., and a treatment for dermatophytes such as T. rubrum.

• KSBB Journal
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• 제23권3호
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• pp.219-225
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• 2008

본 연구는 국외토양으로부터 분리한 400여개의 군주에서 agar plug assay를 이용하여 식물병원균에 대한 항진균성물질을 생산하는 방선균 (I-8)을 분리하였다. 항진균 물질 생산의 최적 조건을 검토한 결과 공시균 I-8은 pH 8로 조정된 ISP No. 2 배지에서 항진균물질 생산성이 가장 우수한 것으로 입증되었다. 공시균 I-8의 식물병원균의 생육저해 기구를 규명하기 위한 기초 연구로서 공시균 I-8이 세포벽 구성성분인 cellulase, chitinase와 같은 가수분해효소를 생산하는 것을 확인하였다. I-8의 배양액은 ethyl acetate추출물에서 식물병원균 14개 균주에 항진균 활성을 나타내었고 ethyl ether추출액에서는 식물병원균 10개 균주에 항진균 활성을 나타내었다. I-8의 ethyl acetate추출물은 공시균인 13-16의 추출물과 혼합사용시 식물병원균인 Monosporascus cannonballus KACC 40940에 대한 항진균력의 상승효과를 확인할 수 있었다. I-8균주 배양체는 고체배지상에서 16개의 식물병원균에 대해 강한 생육저해 효과를 보여, 광범위한 항진균 활성을 나타내는 것을 확인하였다.

• The Plant Pathology Journal
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• 제22권3호
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• pp.295-302
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• 2006

The present study addressed the efficacy of nanosized silica-silver for controlling plant pathogenic microorganisms. The nanosized silica-silver consisted of nano-silver combined with silica molecules and water soluble polymer, prepared by exposing a solution including silver salt, silicate and water soluble polymer to radioactive rays. The nanosized silica-silver showed antifungal activity against the tested phytopathogenic fungi at 3.0 ppm with varied degrees. In contrast, a number of beneficial bacteria or plant pathogenic bacteria were not significantly affected at 10 ppm level but completely inhibited by 100 ppm of nanosized silicasilver. Among the tested plant pathogenic fungi, the new product effectively controlled powdery mildews of pumpkin at 0.3 ppm in both field and greenhouse tests. The pathogens disappeared from the infected leaves 3 days after spray and the plants remained healthy thereafter. Our results suggested that the product developed in this study was effective in controlling various plant fungal diseases.

• 한국미생물·생명공학회지
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• 제25권4호
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• pp.396-402
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• 1997

Biocontrol of plant pathogens provides an alternative means of reducing the incidence of plant diseases without the negative aspects of chemical pesticides. Nowdays, as the resistant fungi about the chemical fungicides have revealed and the concern of environment has increased, the biological control of phytopathogenic fungi by the antagonistic microorganisms is very much indispensable. For the selection of strong antagonistic bacterium for biological control agent of rice leafblast and cucumber gray mold rot, the antifungal strain KL-3 strain was selected among 120 strains isolated from the rhizosphere soils. And the strain was identified to be a species of Bacillus subtilis or closely related strain. In several biochemical and in vitro antibiosis tests, antifungal substances of Bacillus sp. KL-3 were presumed heat stable, micromolecular antibiotic substances. In vivo test and vinyl house field test, the antifungal substances of Bacillus sp. KL-3 represented excellent biocontrol ability aganist Alternaria mali, Phyricularia oryzae, and Alternaria kikuchiana as well as broad spectrum of other fungi. In particular, Bacillus sp. KL-3 strain showed more predominant activity than some chemical fungicides against fungi shown to resist chemcal fungicides.

• Journal of Microbiology and Biotechnology
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• 제5권6호
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• pp.346-352
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• 1995

For isolation of antibiotic-producing bacteria antagonistic to Fusarium oxysporum, a total of 327 microorganisms were screened from sesame-growing soils collected at various locations in Korea by the modified Herr's triple-agar-Iayer technique. Among the 36 bacterial isolates further screened by the dual culture test on tryptic soy agar, 10 were tested to show their antagonistic activity against 14 plant pathogenic fungi. Bacterial culture filtrates were shown either to inhibit some phytopathogenic fungal growth or to suppress F. oxysporum infection of sesame plants maintained in the green house. An isolate, B23, with the most prominent antagonistic activity was identified as Bacillus subtilis.

• 생명과학회지
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• 제17권12호
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• pp.1682-1688
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• 2007

다기능성 농업용 미생물 제제를 개발하기 위하여 생물방제 및 생물비료 활성을 가지는 미생물을 탐색하였다. 본 연구실에서 분리 및 동정된 균주가운데 Pantoea agglomerans 및 Bacillus megaterium을 실험군주로 선정하였으며, 경남 밀양에 위치하는 양계장 부근 부엽토로부터 새로운 다목적 세균 MF12를 분리하였다. 형태학적, 배양적, 생화학적 특성 및 16S rDNA 염기서열을 분석한 결과, MF12는 Bacillus pumilis로 동정되었다. 이 균주들의 불용성 인산 가용능, IAA 및 siderophore 생성능, ammonification ability, 식물병원성 진균 세포성분 분해효소 생성능 및 항진균능을 조사하였다. P. agglomerans는 고체배지에서 불용성 인산을 가용화할 수 없었으나 액체배지에서는 가용성 인산을 생성하였다. 상기 모든 균주들은 배양시간에 따라 $3{\sim}639{\mu}g/ml$의 IAA를 생성하였으며, P. agglomerans만이 siderophore를 생성하였다. 이 균주는 pectinase와 lipase를 생성하였다. B. megaterium은 amylase, pretense 및 lipase를 생성한 반면 B. pumilisr는 protease와 lipase를 생성하였다. P. agglomerans는 Fusarium oxysporum과 Colletotrichum gloeosporioides의 생육을 억제하였으며, B. pumilis는 Botrytis cinerea, Sclerotinia sclerotiorum 및 Phythium ultimum의 생육을 억제하였다.