• 한국균학회지
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• 제19권2호
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• pp.109-119
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• 1991

송이 (Tricholoma matsutake) 생산의 대표적인 지역으로 알려진 강원도 양양 지역과 명주 지역을 선택하여 송이 발생지와 미발생지의 미세균류를 분리 동정하였으며 수직분포를 조사하였다. 진균의 선별방법으로 희석법, $42^{\circ}C$에서 48시간 배양 후 $37^{\circ}C$로 배양하는 방법, $70^{\circ}C$에서 15분간 열처리 방법, 그리고 ethanol처리 방법으로 토양의 수직적 분포를 파악하였다. $42^{\circ}C$배양법에서는 두 장소에서 분리된 토양균은 7속 18종이 분리되었으며, 송이 발생지에서는 Aspergillus fumigatus, A. ochraceus, A. terreus, Acremonium sp., Penicillium frequentans, Talarom-yces stipitatus가 분리되었으며, 송이 미발생지에서는 Aspergillus fumigatus, Penicillium lilacinum, P. oxalicum, Westerdykella multispora가 우점종으로 나타났다. $70^{\circ}C$열처리 방법으로 분리한 경우 7속20종이 분리되었으며, 송이발생지에서는 Aspergillus fumigatus, Mucor sp. 가 우점적으로 나타났으며, 송이 미발생지에서는 A. iumigatus, Atternaria alter-nate, Mucor sp., Neurospora sitophita가 우점종으로 나타났다. Ethanol처리 방법으로 분리한 경우는 1속 1종이 분리되었으며, 송이 발생지와 미발생지에 관계없이 우점종은 Mortierella sp.로 분류되었다. 이들 분리된 토양균은 전체균의 수와 우점종균수 그리고 나타나는 종의 빈도수는 그 수직적 분포에 있어서 상층에서 하층으로 내려갈수록 감소하였다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 추계학술대회 및 정기총회
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• pp.13-13
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• 2014

Species belonging to the genus Fusarium are widely distributed and cause diseases in many plants. Isolation of fungal strains from air or cereals is necessary for disease forecasting, disease diagnosis, and population genetics [1]. Previously we showed that Fusarium species are resistant to toxoflavin produced by the bacterial rice pathogen Burkholderia glumae while other fungal genera are sensitive to the toxin, resulting in the development of a selective medium for Fusarium species using toxoflavin [2]. In this study, we have tried to elucidate the resistant mechanism of F. graminearum against toxoflavin and interaction between the two pathogens in nature. To test whether B. glumae affects the development of F. graminearum, the wild-type F. graminearum strains were incubated with either the bacterial strain or supernatant of the bacterial culture. Both conditions increased the conidial production five times more than when the fungus was incubated alone. While co-incubation resulted in dramatic increase of conidial production, conidia germination delayed by either the bacterial strain or supernatant. These results suggest that certain factors produced by B. glumae induce conidial production and delay conidial germination in F. graminearum. To identify genes related to toxoflavin resistance in F. graminearum, we screened the transcriptional factor mutant library previously generated in F. graminearum [3] and identified one mutant that is sensitive to toxoflavin. We analyzed transcriptomes of the wild-type strain and the mutant strain under either absence or presence of toxoflavin through RNAseq. Expression level of total genes of 13,820 was measured by reads per kilobase per million mapped reads (RPKM). Under the criteria with more than two-fold changes, 1,440 genes were upregulated and 1,267 genes were down-regulated in wild-type strain than mutant strain in response to toxoflavin treatment. A comparison of gene expression profiling between the wild type and mutant through gene ontology analysis showed that genes related to metabolic process and oxidation-reduction process were highly enriched in the mutant strain. The data analyses will focus on elucidating the resistance mechanism of F. graminearum against toxoflavin and the interaction between the two pathogens in rice. Further evolutionary history will be traced through figuring out the gene function in populations and in other filamentous fungi.

• 한국미생물·생명공학회지
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• 제30권1호
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• pp.51-56
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• 2002

국내 토양에서 분리한 식물성 병원균인 Alternaria brassicicola SW-3리 항암활성 물질 생산능을 조사하고, 활성물질을 분리 정제하여 구조를 확인하였다. A. brassicicola SW-3는potato dextrose broth를 이용하여 15$^{\circ}C$에서 2주간 진탕 배양한 다음, MTT assay를 실시하여 항암활성을 확인하였으며, 배양여액 중의 항암물질은 ethyl acetate로 추출하고, silica gel column chromatography로 정제하여 무색의 oily product를 얻었다(수율 22mg/m1). 분리된 물질은 물이나 hexane에는 녹지 않고, chloroform, ethyl acetate, ethanol 등에는 잘 녹는 특징을 보였으며, , $IR^{1}$H-NMR, $^{13}$C-NMR 등을 통해 구조를 분석한 결과, 최근에 일본에서 분리되어 항암효과가 있는 것으로 알려진 depudecin과 동일한 물질로 추정되었다. 본 실험에서 분리된 depudecin은 인체간암세포와 mouse 피부암세포에 대한 세포독성을 나타내었으며, 각각의$ IC_50$ 는 $57\mu$g/ml, $69\mu$g/ml로 나타났다. Alternaria brassicicola SW-3에 의해 생산된 물질이 기지의 물질이지만, depudecin은 아직 작용 기작이나 적용범위 등이 밝혀지지 않은 초기 연구 단계에 있는 물질로서, 새로운 항암제로서의 가능성이 매우 높아 이의 유도체를 합성하거나, 다른 항암제와의 혼용에 의해 부작용이 적은 강력한 항암제를 개발하기 위한 선도물질로 활용될 수 있을 것이다.

• 한국환경농학회지
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• 제36권4호
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• pp.299-305
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• 2017

탄저병이 발생한 자두에서 11개 탄저병균을 순수 분리하여 병원성을 검정한 후 PDA에 접종하여 $25^{\circ}C$에서 7-10일 동안 배양하면서 각 균주의 균사 생장속도, colony의 특징과 색, 포자 형태 및 크기를 관찰하였다. 각 균주의 genomic DNA를 추출하여 rDNA-ITS 영역을 증폭한 다음, PCR을 하여 염기서열을 해독하였다. 각 균주의 배양적 특성, 포자의 형태와 크기 및 염기서열을 NCBI GenBank의 염기서열과 상동성을 비교하여 동정한 결과 6개 균주는 Colletotrichum acutatum으로, 5개 균주는 C. gloeosporioides로 동정되었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제33권2호
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• pp.85-91
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• 2016

Exosomes are homogenous vesicles of 40-100 nm diameter produced endogenously. Exosomes are generated by inward budding into multi-vesicular bodies (MVB) and then released to extracellular space. Exosomes contain various nucleic acid and protein cargoes from their cells of origin and this endosomal cellular molecules are used for intracellular communication and for both promotion and suppression of immune responses. Recently, they are also considered as delivery vehicle for therapeutic proteins due to their characteristics of stability in body fluids and ability for target uptake. Also, they show less immune reactivity because the isolated exosome harboring therapeutic proteins can be from the same host. White-spotted flower chafer, Protaetia brevitarsis is one of the major insect commercially reared in Korea. There are bacterial and fungal pathogens causing diseases in the beetle, and these diseases incur economic loss to the larva-rearing farms. Due to their endosomal cargoes, exosomes are good candidates in use of disease diagnosis. In this study, we isolated insect exosome from the hemolymph of P. brevitarsis, and verified it by analysis of the exosome-specific surface proteins and RNA.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.95.2-96
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• 2003

In order to develop a new microbial fungicide for the control of vegetable diseases using endophytic bacteria, a total of 260 bacterial strains were isolated from fresh tissues of 5 plant species. After they were cultured in broth media, their antifungal activities were screened by in vivo bioassays against Botrytis cinerea(tomato gray mold), Pythium ultimum(cucumber damping-off), Phytopkhora infestans(tomato late blight), Colletotrichum orbiculare(cucumber anthracnose), and Blumeria graminis f. sp. hordei(barley powdery mildew). As the results of screening, 38 bacterial strains showed potent antifungal activities against at least one of 5 plant pathogens. A bacterial strain EB072 displayed potent disease control activities against 3 plant diseases. Among the bacterial strains with a potent antifungal activity against cucunlber anthracnose, three bacterial strains, EB054, EB151 and EB215, also displayed a potent in vitro antifungal activity against C. acutatum, a fungal agent causing pepper anthracnose. A bacterial strain EB215 obtained from roots of cucumber was identified as Burkholderia cepacia based on its physiological and biochemical characteristics and 165 rRNA gene sequence. An antifungal substance was isolated from the liquid cultures of B. cepacia EB215 strain by ethyl acetate partitioning, repeated silica gel column chromatography, and invitro bioassay, Its structural determination is in progress by various instrumental analyses.

• The Plant Pathology Journal
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• 제22권1호
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• pp.75-89
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• 2006

The actinomycete strain JK-1 that showed strong inhibitory activity against some plant pathogenic fungi and oomycetes was isolated from Jung-bal Mountain in Ko-yang, Korea. The strain JK-1 produced spores singly borne on sporophores and the spores were spherical and 0.9-1.2 11m in diameter. The cell wall of the strain JK-1 contained meso-diaminopimelic acid. The actinomycete strain JK-1 was identified as the genus Micromonospora based on the morphological, physiological, biochemical and chemotaxonomic characteristics. From the 168 rDNA analysis, the strain JK-1 was assigned to M aurantiaca. The antibiotic MA-1 was purified from the culture broth of M aurantiaca JK-1 using various purification procedures, such as Diaion HP20 chromatography, C18 flash column chromatography, silica gel flash column chromatography and Sephadex LH-20 column chromatography. $^{1}H-$, $^{13}C-NMR$ and EI mass spectral analysis of the antibiotic MA-1 revealed that the antibiotic MA-1 is identical to phenylacetic acid. Phenylacetic acid showed in vitro inhibitory effects against fungal and oomycete pathogens Alternaria mali, Botrytis cinerea, Magnaporthe grisea, Phytophthora capsici and yeast Saccharomyces cerevisiae at < 100 $\mug$ $ml^{-1}$. In addition, phenylacetic, acid completely inhibited the growth of Sclerotinia sclerotiorum, Bacillus subtilis, Candida albicans, Xanthomonas campestris pv. vesicatoria at < $\mug$ $ml^{-1}$. Phenylacetic acid strongly inhibited conidial germination and hyphal growth of M grisea and C. orbiculare. Phenylacetic acid showed significantly high levels of inhibitory' effect against rice blast and cucumber anthracnose diseases at 250 $\mug$ $ml^{-1}$. The control efficacies of phenylacetic acid against the two diseases were similar to those of commercial compounds tricyclazole, iprobenfos and chlorothalonil .n the greenhouse.

• The Plant Pathology Journal
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• 제30권4호
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• pp.375-383
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• 2014

Fungi tolerate exposure to various abiotic stresses, including cytotoxic compounds and fungicides, via their ATP-driven efflux pumps belonging to ATP-binding cassette (ABC) transporters. To clarify the molecular basis of interaction between the fungus and various abiotic stresses including fungicides, we constructed a cDNA library from germinated conidia of Colletotrichum acutatum, a major anthracnose pathogen of pepper (Capsicum annum L.). Over 1,000 cDNA clones were sequenced, of which single clone exhibited significant nucleotide sequence homology to ABC transporter genes. We isolated three fosmid clones containing the C. acutatum ABC1 (CaABC1) gene in full-length from genomic DNA library screening. The CaABC1 gene consists of 4,059 bp transcript, predicting a 1,353-aa protein. The gene contains the typical ABC signature and Walker A and B motifs. The 5'-flanking region contains a CAAT motif, a TATA box, and a Kozak region. Phylogenetic and structural analysis suggested that the CaABC1 is a typical ABC transporter gene highly conserved in various fungal species, as well as in Chromista, Metazoans, and Viridiplantae. We also found that CaABC1 was up-regulated during conidiation and a minimal medium condition. Moreover, CaABC1 was induced in iprobenfos, kresoxim-methyl, thiophanate-methyl, and hygromycin B. These results demonstrate that CaABC1 is necessary for conidiation, abiotic stress, and various fungicide resistances. These results will provide the basis for further study on the function of ABC transporter genes in C. acutatum.

• 한국임상수의학회지
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• 제8권2호
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• pp.147-152
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• 1991

습도가 높고 환기가 불량하며 비위생적인 우리에서 같이 사육한 두 마리의 어린 염소에서 발생한 진균성피부염의 일차원인이 Trichophyton mentagrophytes이었음을 보고하였다. 두 환축의 진단은 피부소파 시료에 KOH를 사용하여 균요소를 검출하고 3$0^{\circ}C$의 진균배지에서 순수배양하여 균을 분리하여 확인하였다. 한 마리는 안면에서 나머지 한 마리는 목과 귀에서 병변이 발견되었다. 같은 우리에서 사육 중이던 두 마리의 성축에서는 병변이 발견되지 않았다. 더욱이 염소의 주인과 주인가족들에서도 병변이 발견되지 않았다. 두 분리균주를 개량된 sunflower seed medium을 이용하여 유전적 교배실험을 한 결과 둘 다(-) mating type에 속했다. Hair performance test결과 두 균주는 모두 각질용해작용을 나타내었다. 공중위생학적인 중요성과 화학요법에 대해서도 고찰하였다. 감염경로에 대해서는 명확히 밝힐 수 없었다.

• 한국균학회지
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• 제21권3호
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• pp.172-187
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• 1993

전국 각지에서 수거한 메주로부터 29 종의 곰팡이를 분리하였다 . 그 중 접합균은 9 종이였다. 동정된 접합균으로는 M. hiemalis, M. circinelloides f. griseo-cyanus, M. circinelloides, M. jansseni M. racemosus f. racemosus, M. isabellina, R. stolonifer, R. oryzae, 및 A. corymbifera으로 4 속 9 종이었다. 분리된 접합균종 중에서M. circinelloides f. griseo-cyanus, R. stolonifer, R. oryzae은 이미 우리의 재래식 메주에 서식하는 균으로 간장, 된장 등의 장류분야에서 연구 보고도 되었으나, 나머지 6 종은 새로이 기재되는 균들이다. 분리된 9개의 균 각각으로 메주와 간장 된장을 만든 결과 접합균 중, M. hiemalis f. hiemalis. 와 M. circinelloides f. griseo-cyanus는 단독으로 메주가 되고, 우리 구미에 맞는 간장 된장이 되는 것을 관찰하였다. 따라서 이 균은 메주에서 어떤 역할을 하는 것으로 고려된다.