• Applied Biological Chemistry
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• v.48 no.1
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• pp.40-47
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• 2005

In order to develop a multi-microbial biofungicide against several important plant pathogenic fungi, strains were isolated from the phtophthora blight suppressive red-pepper field soil of Gyeongsangbuk-do, Korea. Strains AY1, AY6, AB1, BB2 and F4, which had strong antagonistic ability against Phytophthota capsici and Fusarium oxysporum, were selected for their involvement with strains of biocontrol fungicide. There were no antagonism among the selected strains and were compatible for making the biofungicide. Their antagonistic mechanisms, except for strain BB2, were an antibiosis by the production of antibiotic, while BB2 produced not only an antibiotic but also cellulase as an antagonistic mechanism against blight causing P. capsici. They were identified as Halobacterium sp. AB1, Xenorhadus sp. AY1, Bacillus sp. AY6, Bacillus sp. BB2, Zymomonas sp. F4 by various cultural, biochemical test and $Biolog^{TM}$ System 4.0. The highest levels of antifungal antibiotic could be produced after 48 hrs of incubation under the optimal medium which were 0.1% galactose, 0.1% $NaNO_2$, 5 mM $Na_2{\cdot}HPO_4$ (pH 5.5). The cultured multi-microbial biofungicide showed strong biocontrol activity against bacterial wilt disease and fusarium wilt disease in cucumber and tomato fields.

• The Korean Journal of Mycology
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• v.30 no.2
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• pp.152-156
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• 2002

Distribution and alteration of mating type of Korean population for Phytophthora capsici were monitored from 1995 to 1998. Total 973 isolates collected from 75 pepper fields throughout the country were divided into A1 mating type 573 isolates and A2 mating type 400 isolates. Both mating types were founded in all provinces examined, but the distribution patterns differed between the fields, The single mating type of A1 or A2 isolates was found in some fields, whereas various combinations of both mating types were in all years and provinces surveyed. Ratios of A1 and A2 were varied with years and fields. However, only single mating type either A1 or A2 was detected in some fields. While, in another field located in Gongju, only A2 isolates were detected in 1995 and 1997, but A1 isolates were appeared in 1998. Varied ratios and alterations of A1 and A2 mating type in fields indicate a potential sexual recombination of the fungus, which may cause genetic diversity.

• Korean Journal of Environmental Agriculture
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• v.15 no.4
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• pp.399-405
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• 1996

In the culture medium, the three antifungal fractions against P. capsici were separated by Sephadex G-25 column chromatography and Silica-gel chromatography. The substance A in white powder and the substance B in sticky oil were isolated by ethyl acetate : acetone mixture(7 : 3), and the substance C in yellow powder was isolated by chloroform : ethyl acetate mixture(95 : 5). The crude extract by ethyl acetate from the culture medium acidified to pH 2 was known to inhibit completely the growth of P. capsici at the level of $50mgkg^{-1}$. The substance A and B were known to be effective above the level of $5mgkg^{-1}$, and the substance C was effective above the level of $1mgkg^{-1}$. However, at the level of $20mgkg^{-1}$, the efficiency was in the order of A>C>B. It is apparent on a pot-experiment scale that the three substances effectively control Phytophthora blight of the red-pepper plant grown in the soil inoculated with P. capsici.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.127-133
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• 2012

Inhibition effects on spore germination and mycelia growth for pepper anthracnose fungi (Collectricum acutatum) were investigated in vitro using eco-friendly agricultural materials as well as ecofriendly pesticides. The inhibition effect on mycelia growth of anthracnose fungi is the highest when the anthracnose mycelia were treated with a pesticide (commercial name: Koreayeok) that contains a mixture of Bacillus subtilis and Panibacillus polymyxa, resulting in 100% inhibition of the mycelia growth. Meanwhile, the range of 20~40% inhibition effects on the growth of anthracnose mycelia was observed with other commercial agricultural materials. The significant inhibition effects on spore formation of anthracnose fungus were shown in vitro with two water dispersible pesticides containing sulfur [BTB (100%) and SulfurStar (95.1%)], Koreayeok (95.0%), Borstar (99.0%) containing Bordeaux mixture, and Jihabudea-KM containing Psedomonas spp. (96.1%), respectively. Taken from these in vitro results of inhibiting of the spore germination and mycelia growth together, Koreayeok is the most effective on control of pepper anthracnose disease in vitro. In addition, two water dispersible pesticides containing sulfur (BTB and SulfurStar) and Borstar (99.0%) containing Bordeaux mixture are also significantly applicable to prevent pepper plants from anthracnose disease in vitro. It remains to be determined whether the selected eco-friendly agricultural materials in effective control of anthracnose in vitro can be used to control pepper anthracnose in field.

• Microbiology and Biotechnology Letters
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• v.28 no.6
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• pp.334-340
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• 2000

In order to select multifunctional powerful antagonistic biocontrol agent against red-pepper rotting fungi Phytophthora capsici, we isolated an indigenous antagonistic bacterium which produces antifungal substances and siderophores from a local soil of Kyongju, Korea. The isolated strain was identified as Pseudomonas fluorescens biotype F. The antibiotic produced from P. fluorescens 2112 inhibited hyphae growth and the zoospore germination of Phytophthora capsici. The favorable carbon, nitrogen source and salts for the production of antibiotic from P. fluorescens 2112 were glycerol, beef extract and LiCi at 1.0%, 0.5% and 5 mM, respectively. And antagonistic activity of P. fluorescens 2112 was confirmed against P. capsici in vivo.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.178-186
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• 2012

This study was investigated for the purpose of the isolation and identification of antagonistic bacteria with antifungal activity against plant pathogens. This bacteria denominated Bacillus subtilis KYS-10 and the optimum growth condition were 4% sucrose, 1% yeast extract, 0.2% $K_2HPO_4$, pH 7, 150 rpm, $30^{\circ}C$, 8 day. The antifungal activities against nine plant pathogens determined inhibition zone size by diffusion methods. The results, G. zeae (scab) 70 mm and P. grisea KACC 40439 (blast), P. capsici KACC 40177 (phytophthora blight) and C. destructans KACC 41077 (root rot of ginseng) 40~43 mm, and C. gloeosporioides KACC 43520 (ripe rot), C. gloesporioides KACC 40003 (anthracnose), S. shiraiana KACC 41065 (stem rot) and S. shiraiana (mulberry sclerotial disease) 35~39 mm and F. Oxysporum KACC 44452 (bulb rot of ginseng) 28 mm. From these experiment results, author suggest that Bacillus subtilis KYS-10 would be developed as a biological control agent thorough the field experimet in the near future.

• Journal of Life Science
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• v.9 no.1
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• pp.1-7
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• 1999

To isolate of antagonistic bacteria to Phytophthora capsici, which cause Phytophthora blight in red pepper, 237 isolates of Pseudomonas spp. and 260 isolates of Bacillus spp. were screened in selective media from rhizosphere soils of red pepper at Kyongsan, Kyongju, Yongchon and Euisung in Kyongbuk. Among total 497 isolates, 8 isolates of Pseudomonas spp and 4 isolates of Bacillus spp. inhibited the mycelial growth of Phytophthora capsici above 50$\%$ . These antagonistic bacteria showed more inhibitory effect on TSA (tryptic soy agar) than V-8 juice agar. Four isolates, P0704, P1201, B1101 and B1901, showing the most prominent antagonistic activity were selected and identified as P. cepacia (P0704, P1201), B. polymyxa (B1101) and B. subtilis (B1901), respectively. Cell free filtrates of these isolates were shown to inhibit zoosporangia germination and mycelial growth of p. capsici indicating that these isolates turned out to be bacteria producing antifungal substances. As a result of antagonistic test to Phytophthora blight in green house p. cepacia (P0704) showed the highest antagonistic effect with 46.7$\%$ and the rest of them were in the range of 13.4$\%$ to 26.7$\%$ .

• Journal of Mushroom
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• v.13 no.1
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• pp.16-20
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• 2015

Water extracts from spent mushroom substrate (SMSE)of edible mushrooms, Pleurotus eryngii, Hericium erinaceus and Lentinula edodes promoted growth of pepper seedling. Mycellial growth rate of Phythopthora capsici and Fusarium oxysporum was dramatically inhibited by 100% and 70% on PDA added with SMSE of H. erinaceus. SMSEs from H. erinaceus, P. eryngii, and L. edodes effectively reduced the disease severity of Phytophthora blight of pepper caused by Phytophthora capsici to 75%, 10% and 35%, respectively. These results suggested that SMSE from the mushrooms have dual effects that suppress phythopthora blight disease and promote plant growth of pepper.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.401-406
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• 1992

Antifungal substances against three plant pathogenic fungi, Phytophthora capsici, Phytophthora nicotianae var. parasitica and Rhizoctionaia solani were fractionated cultures of Streptomyces sp. A-2 strain isolated in Korean soils. Characterizations of active substances related with antagonistic effects were follows : 1. The excellent media which showed the transfer efficiency of antagonistic substances from Streptomyces sp. A-2 strain G.Y.B and B.H.I. among four that are glucose yeast broth (G.Y.B), $M\ddot{u}eller$, brain heart infusion(B.H.I.) and Czapek media. Active substances which were transfered into ethylacetate or left in residual aqueous phase did not lose antagonistic activity in spite of autoclavation. This indicated that bonds of these compounds were rigid enough to keep activity under such conditions. 2. Antagonistic substances were extracted according to adjustment of pH 3 or pH12 to 5 day-old B.H.I. broth cultures of Streptomyces sp. A-2 strain. Comparative analysis fluorescent bands on HPTLC to antagonsitic spectra against three phytopathogenic fungi indicated that major substances with antagonistic activity were extracted regardless of different pH adjustment to broth cultures. Since UV spectrum of these fractions scanned from 500nm to 200nm was similiar to that of polyene macrolide, major substances related with antagonistic activities were assumed to be polyene derivatives antibiotics.

• Korean Journal of Environmental Agriculture
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• v.20 no.3
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• pp.180-185
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• 2001

Control effects of phosphorous acid were investigated on Phytophthora blight of red pepper plants in greenhouse and field. In vitro test, the mycelial growth of Phytophthora capsici was inhibited by the phosphorous acid more than 97% at 1,000 ${\mu}g$ and 10,000 ${\mu}g$ a.i./mL in the liquid and solid culture, respectively. At concentration of 10 ${\mu}g$ a.i./mL of phosphorous acid, in the liquid culture the mycelial growth of P. capsici was inhibited 46.2%, however inhibited only 4.9% on the soild culture. Zoosporangial formation was also inhibited 89.1% by phosphorous acid at 100 ${\mu}g$ a.i./mL. Phosphorous acid affected more zoosporangial formation of P. capsici than its mycelial growth. At the concentrations of 10,000, 1,000 and 100 ${\mu}g$ a.i./mL of phosphorous acid, germination of zoosporangia was inhibited 100, 84.3 and 44.2%, respectively. Mycelial growth and zoosporangial formation of P. capsici were little affected at the concentration of 10 ${\mu}g$ a.i./mL of phosphorous acid. Cermination of zoosporangia was also little affected at this concentration, however growth of the germ tubes was inhibited and the abnormal mycelial growth was observed. Phosphorous acid suppressed the incidence of Phytophthora blight of red pepper plants up to $77.0{\sim}62.0%$, in greenhouse. Phosphorous acid suppressed the incidence of Phytophthora blight of red pepper plants up to 54.0% at the conventional culture in field. Treatments of phosphorous acid increased up to 113% in height, 135% in number of fruit, and 129% in weight of fruit.