• Journal of Microbiology and Biotechnology
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• 제3권1호
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• pp.12-18
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• 1993

Pseudomonas aeruginosa strain B5 with antagonistic activity against Phytophthora capsici and Magnaporthe grisea, was isolated from pepper-growing soil. From the culture of P. aeruginosa strain B5 grown on King's medium B, antibiotic substances were purified using XAD-2 column chromatography. XAD-2 eluates inhibited not only the mycelial growth of P. capsid and M. grisea, but also the development of Phytophthora blight on pepper plants. The crude antibiotic substances were further purified by using silica gel column chromatography, Sephadex LH-20 column chromatography, thin layer chromatography on silica gel plates, and high performance liquid chromatography. Silica gel column chromatogrphy gave good separation of the four antibiotic substances. The pure antibiotics P1, P2, and P3 finally purified by preparative HPLC inhibited the mycelial growth of P. capsici, at concentrations from 7 to 10 $\mu g/ml$. Only P1 and P2 had antifungal activity against M. grisea at 8 $\mu g/ml$. P1 and P3 were highly inhibitory to the mycelial growth of Botryosphaeria dothidea and Botrytis cinerea at relatively low concentrations. However, the three antibiotics had no antifungal activity against Rhizoctonia solani. The chemical structures of these antibiotics are being identified.

• Journal of Microbiology
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• 제41권3호
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• pp.196-201
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• 2003

The object of this study was to characterize Bacillus strains GB-017 and GB-0356, which produce antifungal substances, especially for plant pathogens. In addition, this study was undertaken to characterize the culture conditions required for the production of antifungal substances and to document some of the properties of the antifungal substance produced by these soil-isolated strains. Strains GB-0365 and GB-017 were found to be bacillus-shaped, gram-positive and motile, and to inhibit Botrytis cineria, Fusarium sp., Pythium sp., and Rhizoctonia solani. Antagonistic activity was maintained up to pH 9.0, and the antifungal activity was stable to heat at 80$^{\circ}C$ for 1 h. Antifungal substances were separated and purified using ion exchange and adsorption columns including WK-I0(H$\^$＋) (pH 7.0), HP20 column (pH 3.0) and IPA (pH 3.0). and IPA. Its UV absorption spectrum showed major peaks at 231 and 259 nm, corresponding to polyene and lactone. A fast atom bombardment mass spectrum (FAB MS) showed a highest peak at 441 m/z and major peaks at 192, 205, and 370 m/z.

• 한국미생물·생명공학회지
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• 제25권1호
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• pp.62-67
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• 1997

A potential biocontrol bacterium, YB-70 was isolated from a rhizosphere in suppressive soil and identified as a strain of Bacillus subtilis. In several biochemical and in vitro antibiosis tests on Fusarium solani with the culture filterates from B. subtilis YB-70, we found that antifungal mechanism of B. subtilis YB-70 was mediated by antibiotic substances produced from the bacterium. These antifungal substances were appeared to be hear-resistant, micromolecular, and ethy alcohol soluble. Antifungal agents produced by B. subtilis YB-70 showed strong inhibified against root-rotting fungi F. solani in in vivo pot test. An antifungal substance. YBS-1s, was purified from the culture broth of B. subtilis YB-70 by isoelectronic precipitation, silica gel column chromatography and Sephadex LH-20 column chromatography analysis by Fab-MASS, $^{1}$H-NMR, $^{13}$C-NMR, DEPT, and amino acid analyzer revealed that the YBS-1A was a peptide antibiotics of iturin class containing seven amino acids from five different groups, and the other(YBS-1B) was an analogue of iturin group composed of 11 amino acids with larher molecular weight of about 1, 500 dalton, which was lager than that of iturin A.

• 한국미생물·생명공학회지
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• 제28권3호
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• pp.161-166
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• 2000

Monilinia fructicola에 의해 감염되어 미이라화된 복숭아 열매로부터 Monilinia fructicola에 강한 항진균성 물질 chitinase 및 urease을 분비하는 방선균을 분리하였다 선발된 TH-04 균주는 배양적 .형태적 특성 세포벽 성분 및 세포내 당 성분을 분석한 결과 전형적인 Streptomyces속에 속하는 방선균으로 동정되었다. TH-04 균주는 Monilinia fructicola Colletotrichum gloeosporioides Magnaporthe grisea Rhizoctonia solani, Phytophthora capsici, Alternaria kikuchi-ana, Fusarium solani 및 Fusarium oxysporum 등 8종의 식물병원균에 대하여 항진균 활성을 나타냈다. 항생물질 생산을 위한 배양조건은 온도 $20^{\circ}C$, pH 7 및 배양기간 7일로 확인되었다.

• 한국미생물·생명공학회지
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• 제25권5호
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• pp.527-533
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• 1997

From apple skin, we isolated a bacterial strain which strongly inhibited the growth of apple white rot fungus, Botryosphaeria dothidea. The isolated strain, designated as SS279, was identified to be the genus Bacillus. The antifungal activity of Bacillus sp. SS279 was found in the culture filtrate. The production of antifungal substances occurred during logarithmic phase and was the highest when cultures reached the stationary growth phase. The optimum ranges of temperature and pH for its production were 25-30$\circ$C and 4.5-9.0, respectively. The culture filtrate of Bacillus sp. SS279 exhibited a strong inhibitory effect on the spore germination and germ tube elongation of B. dothidea. Autoclaved culture filtrate of Bacillus sp. SS279 showed only a slight decrease in antifungal activity, indicating that the Bacillus sp. SS279 produce heat-stable antifungal substances. In in vivo bioassay, Bacillus sp. SS279 also showed antagonistic activity against apple white rot caused by B. dothidea.

• The Korean Journal of Ecology
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• 제20권3호
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• pp.181-189
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• 1997

Phenolic compounds from 7 species of naturalized invader species and Korean wild plants were analyzed by high performance liquid chromatography. Eleven phenolic compounds including benzoic acid were identified. The extract of naturalized plants was significantly more inhibitory to seed germination and seedling growth of the both naturalized and Korean wild plants. The content of total phenolic compounds in each extract were 43.5 mg/l in Ailanthus altissima as the maximum amount and 25.5 mg/l in Phytolacca americana as the minimum. Phytotoxic substances of ethanol extracts was investigated for antifungal activity against 23 selected fungus species. The antifungal activity of Phytolacca americana showed the greatest clear zone of 23 mm in Aspergillus awamori and its activity had an effect against 6 fungus species. Ailanthus altissima formed the greatest clear zone of 26 mm in Erwinia carotovora sub. sp. carotovora and had an effect agsinst 2 fungus species.

• Journal of Microbiology
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• 제34권3호
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• pp.284-288
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• 1996

Among the bacteria isolated from compost piles of cattle excretion in a pasture located at the suburbs of Chunchon city, Pseudomonas aeruginosa KMCS-1 was selected for the test of antifungal substances produced. Six fractions were separated by silica gel column chromatography, and then the antifungal activity of each fraction was assayed against Escherichia coli, Bacillus subtilis, Candida albicans, Rhizopus sp., Aspergillus nidulans, Coprinus cinereus, and Pyricularia oryzae by paper disc method. Two fractions showed significant suppressive activities against A. nidulans, C. cinereus, and P. oryzae however, their mycelial growth was not affected by neither of these fractions. Inhibitory activities of these fractions to sporulation was assayed at the concentration of 50. 25, 12. 5, and 6.25 $\mu$g/ml and the average inhibition rates against sporulation of A. nidulans, C. cinereus, and P. oryzae were 94.0, 98.3, and 77.9%, respectively. Further purification and analysis of active substances are now being conducted.

• Fisheries and Aquatic Sciences
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• 제5권2호
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• pp.97-102
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• 2002

Pyricularia oryzae (P. oryzae), the cause of rice blast, is one of the most important fungal pathogens of rice. Seventy strains of marine fungi were isolated from marine algae, and it was measured antifungal activity against P. oryzae. Metabolites of marine fungus A-248 which isolated from marine algae showed strong antifungal activity against P. oryzae. The antifungal substance from the metabolites of marine fungus A-248 was extracted with ethylacetate, and then purified by preparative TLC and reverse-phase HPLC. The minimum inhibitory concentration (MIC) value was $0.18\mu g/mL$ for the antifungal activity of the substance purified from A-248 metabolites. The purified substance was similar to antifungal activity of rhizoxin, which is a commercial antifungal agent.

• The Korean Journal of Ecology
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• 제24권3호
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• pp.137-140
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• 2001

개똥쑥(Artemisia annua)에 함유되어 있는 천연화학물질이 곰팡이에 미치는 항균효과를 조사하고 천연화학물질의 성분을 분석하였다. 개똥쑥의 수용성물질과 휘발성물질로 인한 곰팡이의 생장실험은 곰팡이의 종류에 따라 생장률이 다르게 나타났고 수용성물질과 휘발성물질의 농도가 증가 됨에 따라 곰팡이의 생장률이 억제되었다. 특히 Fusarium oxysporum의 경우 휘발성물질보다 수용성물질에서의 생장 억제가 높았고 반면, Aspergillus nidulans는 수용성물질보다 휘발성물질에서 생장이 더 억제되었다. 따라서 이러한 모든 억제작용을 일으키는 화학물질을 찾기 위해 GC/MS를 사용하여 개똥쑥의 정유를 분석한 결과 2,4-hexadienal, β-pinene, cineole, thujone, camphor, citronellal, (-)-menthone, terpineol, (1R)-(-)myrtenol, mytenol, (S)-(-)-perillaaldehyde, perillalcohol, 4-tert-buthylaniline, eugenol, isosafrole, isoeugenol, α-humulene 등이 동정되었다. 이와 같은 결과로 볼때, 개똥쑥에 함유된 수용성 물질과 휘발성 물질이 실험에 쓰인 곰팡이에 대한 항균효과에 관계된다는 사실을 밝혀내었다.

• 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.