• Korean Journal of Pharmacognosy
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• v.37 no.1 s.144
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• pp.21-27
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• 2006

Yeast based estrogenicity assay is the simplest and useful for the assay and the discovery of novel estrogenic substances in natural specimens, The estrogen receptor(ER) modulation activity of 50% EtOH extracts of 101 traditional medicinal herbs was assessed using a recombinant yeast assay system with both a human estrogen receptor expression plasmid and a receptor plasmid. Among them, 14 species proved to be active. Pureariae Flos (flower of Puerraria thunbergiana BENTH.) had the highest estrogenic relative potency$(7.75{\times}10^{-3})$ $(EC_{50}=9.39\;{\mu}g/ml)$. The $EC_{50}$ value of $17{\beta}-estradiol$ used as the positive control was $0.073\;{\mu}g/ml)$ (Relative Potency=1.00). There results demonstrated that some of the traditional medical herb may be useful in the therapy of estrogen replacement.

• Journal of Sericultural and Entomological Science
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• v.40 no.1
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• pp.63-69
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• 1998

Twenty seven out of ca. 5,000 actinomycete strains, which were isolated from soil collected throughout the country, showed antibicrobial effects against fungai, Rhizopus stronifer (ATCC 6227a), Rhizoctonia solani (KCCM 11271) and yeast, Candida albicans (ATCC 10231). From these antifungal microorganisms, we further selected seven strains which seemed to produce insecticidal substances with in vivo test, using silkworm, Bombyx mori and beet armyworm, Spodoptera exigua. Morphological and biochemical experiments revealed that three strains out of seven were Streptomyces. Further investigations on the physical and chemical properties of these antifungal and insecticidal substances are now in progress.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.428-434
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• 2013

An isolate of Bacillus amyloliquefaciens subsp. plantarum CC110 was selected as an effective antagonist for biological control of cucumber downy mildew caused by Pseudoperonospora cubensis. Temperature range for growth of CC110 isolate was $7.5{\sim}55.0^{\circ}C$, and its optimal temperature at $36.6^{\circ}C$. pH range for growth of CC110 isolate was 4.5~9.5, and its optimal pH at 7.0. In this study, the most effective sources of carbon and nitrogen for growth of CC110 isolate were fructose and yeast extract, respectively. The volatile of CC110 isolate was found to be effective to control downy mildew on cucumber showing no diseased area whereas that of control was 13.2% using the I plate bioassay. The culture broth and cells of isolate CC110 cultured in TSB media for 48 hours at $28^{\circ}C$ inhibited occurrence of cucumber downy mildew. The cells and culture broth were transformed into sporangia of P. cubensis by in observation under light microscope and scanning electron microscope.

• Mycobiology
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• v.44 no.3
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• pp.162-170
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• 2016

In this paper, we demonstrate the ability of Arabidopsis thaliana to detect different mixtures of volatile organic compounds (VOCs) emitted by the common indoor fungus, Aspergillus versicolor, and demonstrate the potential usage of the plant as a bioindicator to monitor fungal VOCs in indoor air. We evaluated the volatile production of Aspergillus versicolor strains SRRC 108 (NRRL 3449) and SRRC 2559 (ATCC 32662) grown on nutrient rich fungal medium, and grown under conditions to mimic the substrate encountered in the built environment where fungi would typically grow indoors (moist wallboard and ceiling tiles). Using headspace solid phase microextraction/gas chromatography-mass spectrometry, we analyzed VOC profiles of the two strains. The most abundant compound produced by both strains on all three media was 1-octen-3-ol. Strain SRRC 2559 made several terpenes not detected from strain SRRC 108. Using a split-plate bioassay, we grew Arabidopsis thaliana in a shared atmosphere with VOCs from the two strains of Aspergillus versicolor grown on yeast extract sucrose medium. The VOCs emitted by SRRC 2559 had an adverse impact on seed germination and plant growth. Chemical standards of individual VOCs from the Aspergillus versicolor mixture (2-methyl-1-butanol, 3-methyl-1-butanol, 1-octen-3-ol, limonene, and ${\beta}-farnesene$), and ${\beta}-caryophyllene$ were tested one by one in seed germination and vegetative plant growth assays. The most inhibitory compound to both seed germination and plant growth was 1-octen-3-ol. Our data suggest that Arabidopsis is a useful model for monitoring indoor air quality as it is sensitive to naturally emitted fungal volatile mixtures as well as to chemical standards of individual compounds, and it exhibits relatively quick concentration- and duration-dependent responses.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.447-453
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• 2007

With a broad objective for the development of microbial based fertilizers, a total of 373 strains were isolated from rhizoplane and rhizosphere of pepper, tomato, lettuce, pasture, and grass. The efficacy of the isolates to augument overall plant growth was evaluated. After screening for their plant growth promotion and antagonistic properties in vitro efficient strains were further selected. The most efficient strains was characterized by 16S rRNA gene sequences and biochemical techniques and was designated as Bacillus subtilis S37-2. The strains facilitated plant growth and inhibited the plant phathogenic fungi such as Fusarium oxysporum (KACC 40037, Rhizoctonia solani (KACC 40140), and Sclerotinia sclerotiorum (KACC 40457). Pot based bioassay using lettuce as test plant was conducted by inoculating suspension ($10^5$ to $10^8cells\;mL^{-1}$) of B. subtilis S37-2 to the rhizosphere of lettuce cultivated in soil pots. Compared with non-inoculated pots, marked increase in leaf (42.3%) and root mass (48.7%) was observed in the inoculation group where the 50ml of cell mixture ($8.7{\times}10^8cells\;ml^{-1}$) was applied to the rhizosphere of letuce either once or twice. Antagonistic effects of B. subtilis S37-2 strain on S. sclerotiorum (KACC 40457) were tested. All the tested lettuce plants perished after 9 days in treatment containing only S. sclerotiorum, but only 17% of lettuce was perished in the inoculation plot. B. subtilis grew well in the TSB culture medium. The isolates grew better in yeast extracts than peptone and tryptone as nitrogen source. The growth rate was 2~4 times greater at $37^{\circ}C$ as compared with $30^{\circ}C$ incubation temperature. B. subitlis S37-2 produced $0.1{\mu}g\;ml^{-1}$ of IAA (indole 3-acetic acid) in the TSB medium containing L-tryptophan($20mg\;L^{-1}$) in 24 hours.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.3
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• pp.313-320
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• 2014

In this study, the antimicrobial activity of niaouli leaf extracts was evaluated against skin flora. The skin flora used for experiments were three gram-positive bacteria such as Bacillus subtilis (B. subtilis), Staphylococcus aureus (S. aureus), Propionibacterium acnes (P. acnes), and two gram-negative, Escherichia coli (E. coli), Pseudomonas aeruginosa( P. aeruginosa), and the yeast, Plasmodium ovale (P. ovale). The bioassay applied for determining the antimicrobial effects of niouli leaf extracts or fraction included the disc diffusion assay and broth dilution assay. Minimum inhibitory concentration (MIC) values of 50% ethanol extract on B. subtilis, S. aureus, P. acnes, E. coli and P. aeruginosa were 0.25%, 0.50%, 1.00%, 0.13% and 0.25% respectively and the MIC values of water fraction were 0.25%, 0.25%, 4,00%, 0.25% and 0.25%. P. ovale did not show antimicrobial activities. The MIC values of methyl paraben used as positive control indicated 0.25%, 0.25%, 0.25%, 0.13% and 0.50%. Also, Minimum bactericidal concentration (MBC) values of 50% ethanol extract were 2.00%, 2.00%, 1.00%, 0.50% and 2.00% individually and the MBC values of water fraction were 0.50%, 0.25%, 4.00%, 0.50% and 1.00%. The MBC values of methyl paraben indicated 1.00%, 0.500%, 0.50%, 0.50% and 1.00%. These results showed that water fraction was as good as methyl paraben except for P. acnes. The 50% ethanol extract also showed activity similar with it. Thus, it is concluded that the 50% ethanol extract/fraction of niaouli could be applicable to cosmetics as a natural preservatives effective in antimicrobial activity against skin flora.