• 농약과학회지
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• 제4권3호
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• pp.52-59
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• 2000

Saccharomyces cerevisiae를 이용하여 효율적인 호흡저해 스크리닝 방법을 개발하고자 실험하였다. S. cerevisiae균을 glucose 발효와 미토콘드리아 호흡이 가능한 yeast extract-peptone-dextrose (YPD) 배지와 단지 미토콘드리아 호흡만이 가능한 non-fermentable carbon source-yeast extract (NFY) 배지로 수확하였다. 96-well plate의 각 well에 균 현탁액을 분주한 다음 다양한 작용기작의 46개 살균제를 여러 가지 농도로 처리하였다. NFY배지에서의 non-fermentable carbon source로는 ethanol (NFY-E배지) 및 glycerol (NFY-G배지), lactate (NFY-L배지)를 이용하였다. 접종 후 $1{\sim}3$일 동안 배양한 다음 최소억제농도 (minimum inhibitory concentration, MIC)를 결정한 결과, 4개의 호흡억제 살균제인 azoxystrobin, kresoxim-methyl, metominostrobin, trifloxystrobin은 YPD 배지에서 균의 생육을 전혀 억제하지 못하였으나, 세가지 NFY배지에서는 높은 항균활성을 보였다. 이와는 반대로 5개의 N-trihalomethylthio계 살균제는 NFY배지보다 YPD 배지에서 높은 활성을 보였다. 그리고 11개 살균제는 두 배지 모두에서 같은 항균활성을 나타내었고, 나머지 26개의 살균제는 모든 배지에서 전혀 항균활성을 보이지 않았다. 그러므로 S. cerevisiae와 96-well plate를 이용한 호흡저해제 검정법은 신속하고 편리하게 호흡저해제를 스크리닝 할 수 있는 방법으로 여겨진다.

• 생명과학회지
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• 제13권5호
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• pp.604-617
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• 2003

안전성이 확보된 식용, 또는 약용식물로부터 항캔디다 활성이 우수한 항진균 후보물질을 개발하기 위해, 298종의 천연물로부터 추출부위 및 추출 용매를 달리하여 384종의 추출물을 제조하였다. 제조된 추출물의 항캔디다 활성을 disc-paper를 이용한 생육 저지환의 유무 및 크기 판정과 microbroth dilution법을 이용하여 C. albicans KCTC 1940과 S. cerevisiae IFO 0233를 대상으로 평가하였다. 그 결과 20종 식물로부터 조제된 25종의 추출물이 우수한 항캔디다 활성을 나타냄을 확인하였고, 그 중에서도 멍석딸기, 정향, 천황련, 작약, 모란, 대극잎 추출물은 강력 한 항캔디다 활성$(MIC=50 \mug/m\ell)$을 보였다. 특히, 멍석딸기(에틸아세테이트 추출물), 정향(부탄올 추출물), 호장근(에틸아세테이트 추출물), 작약(부탄올 추출물), 대극잎(메탄올 추출물)의 경우에는 C. albicans에 높은 선택독성을 나타내어, 안정성이 확보된 식물 추출물로부터 새로운 진균 감염증 치료제 개발이 가능함을 제시하였다.

• 농약과학회지
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• 제8권1호
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• pp.8-15
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• 2004

베타-케토아세트아닐라이드 염화물 유도체의 합성 및 이들 화합물의 대표적인 6종의 식물병원균에 대한 항균력을 조사하였다. Carousel Reaction Stations 장치를 이용하여 조합 합성 기법을 통하여 키틴 이합 체를 염소와 아닐린 유도체와 차례로 반응시켜 89종의 베타-케토아세트아닐라이드 클로라이드 유도체를 얻었다. 합성된 화합물 라이브러리의 항균력(in vivo)을 벼 도열병, 벼 잎집무늬마름병, 토마토 잿빛곰팡이병, 토마토 잎마름역병, 밀 붉은녹병, 보리 흰가루병 등의 주요 식물병에 대한 항균력 시험을 수행하였다. 일반적으로 페닐기의 4위치 (para) 치환체가 존재하는 화합물의 경우에 선택적으로 토마토 잎마름역병을 방제하였다.

• 한국균학회지
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• 제23권2호통권73호
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• pp.176-189
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• 1995

98종의 한국산버섯의 그람음성균에 대한 항균활성을 검색한 결과 20종의 버섯의 80% 에탄올(E) 및 증류수(H) 추출물이 Klebsiella pneumoniae, Proteus mirabilis, Serratia marcescens, Shiegella sonnei, Shiegella dysenteiae, Salmonella typhi, Salmonella typhimurium 및 Pseudomonas aeruginosa에 대하여 항균력을 나타내며, 특히 R. sinuatus, S. luteus, B. umbriniporus, 그리고 A. tabescens의 E 추출물은 다른 버섯에 비하여 여러 종류의 그람음성균에 대하여 다양한 항균활성을 보였다. Abortiporus biennis, Phellinus gilvus, 및 Polyporus dispansus의 E 추출물은 S. typhi에 대하여 강력한 항균력을 나타내었으며 이들의 MIC는 $10\;{\mu}g/ml$이었다. 25종 버섯의 곰팡이균에 대한 항균활성을 검색한 결과 Armillariella tabescens의 E 추출물이 Trichopyton mentagrophytes에 대하여 항균력을 가지며 이의 MIC는 $300\;{\mu}g/ml$이었다.

• Mycobiology
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• 제48권4호
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• pp.326-329
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• 2020

Valuable natural compounds produced by a variety of microorganisms can be used as lead molecules for development of new agrochemicals. Furthermore, high-throughput in vitro screening systems with specific modes of action can increase the probability of discovery of new fungicides. In the current study, a rapid assay tested with various microbes was developed to determine the degree of respiratory inhibition of Saccharomyces cerevisiae in two different liquid media, YG (containing a fermentable carbon source) and NFYG (containing a non-fermentable carbon source). Based on this system, we screened 100 fungal isolates that were classified into basidiomycetes, to find microbial secondary metabolites that act as respiratory inhibitors. Consequently, of the 100 fungal species tested, the culture broth of an IUM04881 isolate inhibited growth of S. cerevisiae in NFYG medium, but not in YG medium. The result is comparable to that from treatment with kresoxim-methyl used as a control, suggesting that the culture broth of IUM04881 isolate might contain active compounds showing the inhibition activity for respiratory chain. Based on the assay developed in this study and spectroscopic analysis, we isolated and identified an antifungal compound (-)-oudemansin A from culture broth of IUM04881 that is identified as Oudemansiella venosolamellata. This is the first report that (-)-oudemansin A is identified from O. venosolamellata in Korea. Taken together, the development of this assay will accelerate efforts to find and identify natural respiratory inhibitors from various microbes.

• 한국미생물·생명공학회지
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• 제24권1호
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• pp.77-81
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• 1996

During the screening for the antifungal compounds against Phytophthora capsici causing phytophthora blight of red pepper, we isolated a strong active compound, bafilomycin $C_1$, produced by strain 3D3. The producing organism was identified as Streptomyces sp. based on taxonomic studies. The antifungal compound was purified from culture broth by HP-20 column chromatography, ethylacetate extraction, silica gel column chromatography and HPLC, and was identified as bafilomycin $C_1$ by color reaction, UV and $^{1}H$-NMR spectral data analysis. Bafilomycin $C_1$ showed strong antifungal activity against various phytopathogenic fungi.

• Applied Biological Chemistry
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• 제47권1호
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• pp.154-156
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• 2004

• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.465-468
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• 2006

Even though many pesticides are known for barley powdery mildew and wheat leaf rust, alternative controls are necessary, because of consumer rejection of chemical pesticides and the appearance of fungi resistant to fungicides. To discover biopesticides, many broths of microorganisms were screened. Of those, a culture broth of Burkholderia ambifaria showed an excellent antifungal activity against both Erysiphe graminis and Puccinia recondita, which cause barley powdery mildew and wheat leaf rust, respectively.

• 식품보건융합연구
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• 제6권3호
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• pp.5-21
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• 2020

Bungkang (Syzygium polyanthum) is a medium to tall plant which produces medicinal root-bark, the plant is normally found along inland river bank and produces small white flowers and fruits. Essential oils are among the most interesting components of the plant extracts consisting mostly of monoterpenoid or sesquiterpenoids. They are used as therapeutic agents in ethno, conventional, and complementary alternative medicines. Investigation and evaluation of the essential oil of Syzygium polyanthum as well as the antibacterial, antioxidant and antifungal activity was ascertained. The experiment was performed. 100 chemical constituents were obtained and two pure compound was isolated as Eugenol (1) and Farnesol (2). Significant growth inhibition of Staphylococcus aureus, (ATCCⓒ25923) Klebsiellia pneumonia (ATCCⓒ19155), Salmonella typhi (ATCCⓒ14028) and Escherichia coli (ATCC©25922) and the fungal strains Aspergillus flavin, Aspergillus niger, Candida, tropicalis, and Fusarium oxysporium was observed from the essential oil at concentration of 500 ㎍/mL. Antioxidant potential was observed to be strong of 18.42 ㎍/mL when compared to the control of 15.23 ㎍/mL. The result indicated that the oil obtained from root-bark of Syzygium polyanthum can be considered as an agent for antioxidant, antibacterial and antifungal in pharmaceutical food and cosmetic industries trails.

• Journal of Microbiology and Biotechnology
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• 제32권7호
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• pp.911-917
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• 2022

As valuable antibiotics, microbial natural products have been in use for decades in various fields. Among them are polyene compounds including nystatin, amphotericin, and nystatin-like Pseudonocardia polyenes (NPPs). Polyene macrolides are known to possess various biological effects, such as antifungal and antiviral activities. NPP A1, which is produced by Pseudonocardia autotrophica, contains a unique disaccharide moiety in the tetraene macrolide backbone. NPP B1, with a heptane structure and improved antifungal activity, was then developed via genetic manipulation of the NPP A1 biosynthetic gene cluster (BGC). Here, we generated a Streptomyces artificial chromosomal DNA library to isolate a large-sized NPP B1 BGC. The NPP B1 BGC was successfully isolated from P. autotrophica chromosome through the construction and screening of a bacterial artificial chromosome (BAC) library, even though the isolated 140-kb BAC clone (named pNPPB1s) lacked approximately 8 kb of the right-end portion of the NPP B1 BGC. The additional introduction of the pNPPB1s as well as co-expression of the 32-kb portion including the missing 8 kb led to a 7.3-fold increase in the production level of NPP B1 in P. autotrophica. The qRT-PCR confirmed that the transcription level of NPP B1 BGC was significantly increased in the P. autotrophica strain containing two copies of the NPP B1 BGCs. Interestingly, the NPP B1 exhibited a previously unidentified SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) inhibition activity in vitro. These results suggest that the Streptomyces BAC cloning of a large-sized, natural product BGC is a valuable approach for titer improvement and biological activity screening of natural products in actinomycetes.