• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.294-297
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• 2001

Sophorolipid, a biosurfactant produced from Candida bombicola ATCC 22214. showed antimicrobial activity against Bacillus subtilis. Staphylococcus xylosus, Streptococcus mutans, and Propionibacterium acne at 4, 1, 1, 0.5 ppm as MIC(minimum inhibitory concentration). Also 100ppm of sophorolipid inhibited 50% of cell growth of plant pathogenic fungus. Botrytis cinerea. However, sophorolipid showed no effect on the Escherichia coli, indicating its selective antimicrobial activity depending on the cell wall structure. Treatment of B. subtilis with sophorolipid increased the leakage of intracellular enzyme, malate dehydrogenase, indicating the possible interaction of sophorolipid with cellular membrane. Between lactone-type and acid-type sophorolipid, the former showed higher antimicrobial activity.

• Journal of Life Science
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• v.14 no.6 s.67
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• pp.1003-1008
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• 2004

11 plant essential oils are screened in vitro for their antifungal activities against Botrytis cinerea, Fusarium oxysporum and Rhizoctonia solani, which are causative agents of serious plant diseases. The radial growth of the test fungi were reduced in response to the oils. Among them, the essential oil from the bark of Cinnamomum zeylanicum inhibited 3 tested fungi growth, strongly, followed by those of oregano and thyme. The major constituents of the three essential oils, cinnaldehyde, carvacrol and thymol were tested for their effects on the fungi. From the results obtained, cinnamaldehyde, the major constituents of C. zeylanicum bark esential oil, has potential to be developed as a biopesticide for controlling phytopathogenic fungi causing serious damages on the important crops cultivated in Korea.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.432-436
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• 2014

The soil-borne ascomycete fungus Cylindrocarpon destructans causes ginseng root rot disease and produces various secondary metabolites such as brefeldin A and radicicol. The slow growth of this fungus compared with other plant pathogenic and saprophytic fungi in soil disturbs isolation of this fungus from soil and infected ginseng. In this study, we developed a selective medium for C. destructans using radicicol produced by this fungus. Supplementing 50 mg/L of radicicol to medium inhibited the mycelia growth of other fungi including Botrytis cinerea, Rhizoctonia solani and Alternaria panax, but did not affect the growth of C. destructans. In addition, conidia germination of other fungal species except for C. destructans was inhibited in submerged culture supplemented with radicicol. This medium provides a very efficient tool for isolating C. destructans and also can be used as an enrichment medium for this fungus.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.1120-1123
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• 2001

Screening tests against six plant pathogenic fungi were performed in order to develop biopesticides. Actinomycetes were used to discriminate Bacillus thuringiensis for wide use as a microbial pesticide. From more than 100 actinomycetes tested, twelve strains showed potent antifungal activities. We report in vivo screening results from fermentation broths of these twelve strains and identification of the strain taxa.

• Journal of Applied Biological Chemistry
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• v.49 no.4
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• pp.131-134
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• 2006

The in vitro anti-fungal activity of hydroxylated fatty acids obtained from microbial conversion by Psuedomonas aeruginosa PR3 using ricinoleic acid(RA), eicosadienoic acid(EDA) and conjugated linoleic acid(CLA) as substrates, was investigated. Bioconverted hydroxylated fatty acids showed different anti-fungal activities potentials against the range of phytopathogenic fungi such as Botrytis cinerea, Rhizoctonia solani, Fusarium oxysporum, Sclerotonia sclerotiorum, Colletotricum capsici, Fusarium solani and Phytophthora capsici. RA and EDA showed up to 50% fungal mycelial inhibition at the concentration of $5{\mu}l\;ml^{-1}$. RA, EDA and CLA also exhibited anti-fungal activities with minimum inhibitory concentration(MIC), ranging from 500 to $1000{\mu}g\;ml^{-1}$. Screening was also carried out using varied concentrations of bioconverted RA and EDA for determining the anti-fungal effect on the spore germination of different fungi. Bioconverted RA and EDA showed a considerable degree of spore germination inhibition.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.247-249
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• 2000

Antimicrobial activity of sophorolipid produced by Candida bombicola ATCC 22214 was investigated, Minimum inhibitory concentration of sophorolipid to Propionibacterium acne and Bacillus subtilis were 0.5 ppm and 4 ppm, respectively. However no antimicrobial activity to E. coli was detected. Indicating the antimicrobial activity of sophorolipid only toward gram positive bacteria. Antifungal activity of sophorolipid was also detected in the hyphae growth assay for Botrytis cinerea. Malate dehydrogenase, a cytoplasmic enzyme, of B. subtilis was remarkably increased with the sophorolipid treatment, indicating the leakage of membrane by sophorolipid. This result shows the potentials of sophorolipid as mild, non-toxic antimicrobial agent.

• Journal of Plant Biotechnology
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• v.38 no.4
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• pp.278-284
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• 2011

The CCR4-CAF1-NOT complex-mediated degradation of mRNA is a fundamental aspect of gene regulation in eukaryotes. We herein examined the role of AtCAF1 in the innate immune and wound responses of plants. Our results showed that overexpression of AtCAF1 significantly downregulated the transcript level of EFR but not FLS2 and BRI1, as well as abolished up-regulated expression pattern of EFR in response to wounding. Consistently, Agrobacteriummediated transient expression of GUS was highly enhanced in the transgenic plants overexpressing AtCAF. Furthermore, JA responsive genes were down-regulated by overexpression of AtCAF, causing the transgenic plants overexpressing AtCAF more susceptible to necrotrophic fungal pathogen, Botrytis cinerea. These results suggest that The CCR4-CAF1-NOT complex-mediated degradation of mRNA negatively regulates wounding-mediated disease resistance in Arabidopsis thaliana.

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.550-551
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• 2006

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.2
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• pp.67-72
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• 2002

The two stage laccase-assisted delignification process led to significant lignin removal in the non-pressurized treatments. It is clearly shown that an alkaline extraction prior to the second laccase treatment significantly increased the overall delignification by ∼15%. This is in line with the contention that the residual lignin has undergone structural changes during the alkaline extraction, and the resulting modified structures are susceptible to the laccase oxidation. In phenolic hydroxyl group, the pre- methylated sample was very responsive to the delignification process. The phenolic hydroxyl groups could be increased during side chain cleavage catalyzed by laccase. This finding demonstrates that the delignification oi etherified structures is an important reaction in the delignificaton by laccase.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.10a
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• pp.54.2-54
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• 1999