• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.2071-2075
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• 2007

Fourteen Bacillus thuringiensis isolates having both insecticidal activity and in vitro antifungal activity were selected and tested for in vivo antifungal activity against tomato late blight, wheat leaf rust, tomato gray mold, and barley powdery mildew in growth chambers. All the isolates represented more than 70% disease control efficacy against at least one of four plant diseases. Specifically, 12 isolates exhibited strong control activity against barley powdery mildew. Under glasshouse conditions, four (50-02, 52-08, 52-16, and 52-18) of the isolates also displayed potent control efficacy against cucumber powdery mildew. To our knowledge, this is the first report of B. thuringiensis isolates that have disease control efficacy against powdery mildew of barley and cucumber as well as insecticidal activity.

• Journal of Microbiology and Biotechnology
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• 제9권5호
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• pp.672-674
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• 1999

Cepacidine A was first identified as a novel antifungal antibiotic which was isolated from the culture broth of Pseudomonas cepacia AF200l. It showed a potent in vitro antifungal activity against various pathogenic fungi, but did not show any activity against bacteria. Recently, the immunosuppressive action of cepacidine A was discovered using an in vitro screening system involving inhibition of the proliferation of murine lymphocytes stimulated by 2 mitogens, and also by in vivo mouse models involving inhibition of delayed type hypersensitivity and SRBC hemagglutination. Cepacidine A showed a significant activity of cellular immunosuppression (ED/sub 50/) at concentration levels of 1-3 ㎎/㎏, i.p.. Unfortunately, the delayed toxicity at a dose of above 3 ㎎/㎏ i.p. was apparent.

• The Plant Pathology Journal
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• 제20권3호
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• pp.184-191
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• 2004

Methanol extracts of fresh materials of 57 plants were screened for in vivo antifungal activity against Magna-porthe grisea, Corticium sasaki, Botrytis cinerea, Phyto-phthora infestans, Puccinia recondita, and Blumeria graminis f. sp. hordei. Among them, seven plant extracts showed disease-control efficacy of more than 90％ against at least one of six plant diseases. None of the plant extracts was highly active against tomato gray mold. The methanol extracts of Chloranthus japonicus (roots) (CjR) and Paulownia coreana (stems) (PcS) displayed the highest antifungal activity; the CjR extract controlled the development of rice blast, rice sheath blight, and wheat leaf rust more than 90％, and tomato gray mold and tomato late blight more than 80％. The PcS extract displayed control values of more than 90 ％ against rice blast, wheat leaf rust, and barley powdery mildew and more than 80％ against tomato gray mold. The extract of PcS also had a curative activity against rice sheath blight and that of CjR had a little curative activity against rice blast. On the other hand, the extract of Rumex acetocella roots reduced specifically the development of barley powdery mildew. Further studies on the characterization of antifungal substances in antifungal plant extracts are underway and their disease-control efficacy should be examined under greenhouse and field conditions.

• Journal of Microbiology and Biotechnology
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• 제12권6호
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• pp.1026-1028
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• 2002

Screening tests against fungus causing rice blast, Magnaporthe grisea, were performed in order to develop biopesticides. More than 400 actinomycetes collected at several sites near Hanla Mountain on Jeju Island, Korea were tested, and strain BG2-53 showed potent antifungal activity. The in vivo screening was performed with fermentation broth, and the strain taxon was identified.

• 한국미생물·생명공학회지
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• 제30권4호
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• pp.339-345
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• 2002

가지에서 분리한 F. equiseti FO-68균주와 벗풀에서 분리한 Fusarium sp. FO-510균주로부터 항균물질을 분리한 후 이들의 식물병원곰팡이에 대한 항균활성을 in vitro및 in vivo에서 조사하였다. FO-68균주의 쌀배양체로부터 하나의 항생물질을 순화하였는데 , 이 물질은 equisetin이라는 물질로 동정되었다. 그리고 FO-510균주의 쌀배양체로부터는 두 개의 항균활성 물질을 분리하였는데, 이들은 zearalenone과 8'-hydroxyzearalenone으로 동정되었다. Equisetin과 zearalenone은 in vitro에서 실험한 식물병원곰팡이 대부분에 대해서 높은 항균활성을 보였지만, 8'-hydroxyzearalenone은 거의 항균활성이 없었다. In vivo assay에서 equisetin은 토마토ㆍ잿빛곰팡이병과 토마토ㆍ역병에 방제효과가 컸으며, zearalenone은 벼ㆍ도열병, 벼ㆍ잎집무의마름병, 토마토ㆍ잿빛곰팡이병 및 토마토ㆍ역병에 대하여 효과를 나타내었다. 하지만 8'-hydroxyzearalenone는 토마토ㆍ잿빛곰팡이병을 제외한 나머지 식물병의 발생은 억제하지 못했다. Equisetin, zearalenone 및 8'-hydroxyzearalenone의 항진균활성은 본 논문에서 처음으로 보고하는 바이다.

• Mycobiology
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• 제31권3호
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• pp.179-182
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• 2003

A total of 187 endophytic fungi were isolated from 11 plant species, which were collected from 11 locations in Korea. Their antifungal activities were screened in vivo by antifungal bioassays after they were cultured in potato dextrose broth and rice solid media. Antifungal activity against plant pathogenic fungi such as Magnaporthe grisea(rice blast), Corticium sasaki(rice sheath blight), Botrytis cinerea(tomato gray mold), Phytophthora infestans(tomato late blight), Puccinia recondita(wheat leaf rust), and Blumeria graminis f. sp. hordei(barley powdery mildew) was determined in vivo by observing the inhibition of plant disease development. Twenty(11.7%) endophytic fungi fermentation broths were able to control, by more than 90%, at least one of the six plant diseases tested. Among 187 liquid broths, the F0010 strain isolated from Abies holophylla had the most potent disease control activity; it showed control values of more than 90% against five plant diseases, except for tomato late blight. On the other hand, fourteen(7.5%) solid culture extracts exhibited potent disease control values of more than 90% against one of six plant diseases. The screening results of this study strongly suggested that metabolites of plant endophytic fungi could be good potential sources for screening programs of bioactive natural products.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.112-117
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• 2005

Abstract Griseofulvin has been used as an antifungal antibiotic for the treatment of mycotic diseases of humans and veterinary animals. The purpose of this work was to identify a griseofulvin-producing endophytic fungus from Abies holophylla and evaluate its in vivo antifungal activity against plant pathogenic fungi. Based on nuclear ribosomal ITS1-5.8SITS2 sequence analysis, the fungus was identified and labeled as Xylaria sp. F0010. Two antifungal substances were purified from liquid cultures of Xylaria sp. F0010, and their chemical identities were determined to be griseofulvin and dechlorogriseofulvin through mass and NMR spectral analyses. Compared to dechlorogriseofulvin, griseofulvin showed high in vivo and in vitro antifungal activity, and effectively controlled the development of rice blast (Magnaporthe grisea), rice sheath blight (Corticium sasaki), wheat leaf rust (Puccinia recondita), and barley powdery mildew (Blumeria graminis f. sp. hordei), at doses of 50 to 150 ${\mu}$g/ml, depending on the disease. This is the first report on the production of griseofulvin and dechlorogriseofulvin by Xylaria species.

• 한국약용작물학회지
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• 제17권6호
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• pp.464-469
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• 2009

This study was conducted to find out environment-friendly disease control method to Alternaria blight caused by Alternaria panax of ginseng. For this study, 150 methanol extracts from medicinal plants were evaluated and the extract of Impatiens balsamina showed most strong antifungal activity against A. panax. The methanol extract of I. balsamina showed also stable antifungal activity against other ginseng pathogens such as Botrytis cinerea and Fusarium sp., when treated by heat or pH. In vivo, Alternaria blight incidence rate was low of 13% with the treatment of I. balsamina methanol extract compared to 35% of the non-treatment. The antifungal compound of I. balsamina was purified and identified by using a silica gel column chromatography, TLC and ESI-LC/MS/MS analysis. The compound which showed strong antifungal activity was identified as 2-methoxy-1,4-naphtoquinone ($C_{11}H_8O_3$).

• 농약과학회지
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• 제9권4호
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• pp.422-428
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• 2005

배추 유묘를 Plasmodiophora brassicae 오염토에 이식하고 약제 용액을 폿트(35 $cm^2$)에 관주처리 하는 방법으로 기존 살균제 44종의 배추 뿌리혹병에 대한 방제효과를 실험하였다. 뿌리혹병 방제용 살균제인 fluazinam, flusulfamide 및 cyazofamid는 폿트 당 0.63 mg 처리구에서 모두 90% 이상의 방제가를 나타냈다. 난균류 병해 살균제인 ethaboxam과 cymoxanil은 폿트 당 5 mg 처리 시에 배추 뿌리혹병을 완전히 방제하였다. 그러나 cymoxanil은 고농도 처리에서 배추에 심한 약해를 유발하였다. 잿빛곰팡이병 방제용 살균제인 dichlofluanid와 procymidone도 폿트 당 2.5 mg 처리 시에 배추 뿌리혹병을 효과적으로 방제하였다. 광범위살균제인 chlorothalonil, quintozene과 trichlamide도 2.5 mg 처리 시에 각각 85%, 100%, 100%의 방제가를 나타냈다. 스테롤 생합성 저해제는 대부분 배추 뿌리혹병에 우수한 방제효과를 나타냈으나, 이들은 배추 유묘의 생육을 억제하는 약해를 나타냈다. 이상의 결과로부터 선발된 7종 살균제의 배추 뿌리혹병 방제효과를 비교하여 실험한 결과, 이들 중 ethaboxam은 가장 우수한 방제효과를 나타냈으며 fenarimol, pocymidone, nuarimol, chlorothalonil 순으로 우수한 방제효과를 보였다.

• 농약과학회지
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• 제10권4호
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• pp.249-261
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• 2006

살균활성이 있는 4-isopropyl-3-methylphenol(I)과 5-isopropyl-3-methylphenol(II)을 출발물질로 하여 ester, sulfonyl ester, carbamate, ether 및 phosphoyl ester계열의 50개 화합물들을 합성하였으며, IR, GC/MS와 $^1H$-NMR spectrum을 이용하여 합성을 확인하였다. 이 유도체들에 대한 in vitro 살균활성 실험을 10종의 식물병원균에 대하여 실시한 결과 몇 가지 화합물이 우수한 항균활성을 나타내었다. 이들 화합물을 5가지 식물병(벼도열병, 토마토역병, 오이 잿빛곰팡이병, 벼 잎집무늬 마름병, 오이탄저병)에 대하여 in vivo 항균활성을 조사하였다. 그 결과, 4-isopropyl-3-methylphenyl (2-aminothiazole-4-yl)methoxyiminoacetate(I-7a)는 벼 도열병(Pycularia oryzae)에 methyl (4-isopropyl-3-methylphenoxy)acetate(I-4d)와 methyl (5-isopropyl-3-methylphenoxy) acetate (II-4d)는 오이 잿빛곰팡이병(Botrytis cinerea)에 높은 방제활성을 나타내었다.