• Korean Journal of Microbiology
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• v.52 no.2
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• pp.212-219
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• 2016

Forty-nine pigments were extracted from the collections of 106 pigment producing bacteria from the plant rhizosphere soil. Antibacterial activity test was performed in the subjects of the extracted pigments with plant pathogenic bacteria including Xanthomonas axonopodis and Xanthomonas campestris, and with plant pathogenic fungi including Botrytis cinerea, Colletotrichum acutatum, and Fusarium oxysporum. The yellow pigment by Chryseobacterium sp. RBR9 and the red pigment by of Methylobacterium sp. RI13 showed the antibacterial activities against Xanthomonas axonopodis and Xanthomonas campestris. The violet pigment by Collimonas sp. DEC-B5 showed the antibacterial activity as well as the antifungal activities against Botrytis cinerea and Fusarium oxysporum. Especially, the violet pigment inhibited the growth of Botrytis cinerea more than 65% at MIC $20{\mu}M$. Upon the HPLC analysis result for the isolation of pigment with antifungal activity, violacein (91.6%) and deoxyviolacein (8.4%) were isolated for the pigment by Collimonas sp. DEC-B5. The production amount of the pigment was increased more than 10 times higher when D-mannitol 1.5% and yeast extract 0.2% were added as the nitrogen source to SCB medium. This study suggests that produced violacein by Collimonas sp. DEC-B5 will be effective to control strawberry gray-mold rot fungi by its preventive activity.

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.71-79
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• 2015

In order to investigating the effects of antifungal activity of intestinal bacteria obtained from insect, it was identified these bacteria isolated from the gut. In this result, total 49 isolates of intestinal bacteria were identified from 10 kinds of insect species. It was that 4 isolates including Cedecea sp. from Nesidiocoris tenuis, 3 isolates including Enterobacter sp. from Odontotaenius disjunctus, 4 isolates including Acinetobacter sp. from Reticulitermes speratus, 4 isolates including Clavibacter sp. from Riptortus clavatus, 11 isolates including Bacillus sp. from Lema decempunctata, 3 isolates including Enterococcus sp. from Henosepilachna vigintioctopunctata 2 isolates including Staphylococccus sp. from Harmonia axyridis, 5 isolates including Enterobacter asburiae from Popillia mutans, 7 isolates including Aeromonas sp. from Hydrophilus acuminatus, and 7 isolates including Brucella sp. from Anomala octiescostata. In order to investigating antifungal activity against plant-pathogenic fungi, Altanaria solani, Colletotrichum gloeosporioides, Botrytis cinerea, Fusarium oxysporum, Phytophthora capsici, Rhizoctonia solani and Selerotinia sclerotiorum were dual cultured with each 49 gut enterobacteriaceae. As these results showed that many isolates have the antifungal activities including 26 isolates against A. solani, 6 isolates against B. cinerea, 13 isolates against C. gloeosporioides, 11 isolates against F. oxysporum, 17 isolates P. capsici, 2 isolates against R. solani and 2 isolates against S. sclerotiorum. Pseudomonas aeruginosa was showed strong antifungal activity against all of tested plant pathogens. It might be taken a potential for application against plant-pathogenic fungi with useful control agent.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.7-13
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• 1999

Thirty bacteria were isolated from the red pepper rhizosphere. The isolates were screened for antagonism to Alternaria alteranta causing red pepper black rot. Antagonistic bacterium No. J-24 was selected among the isolated bacteria and was identified as Bacillus subtilis based on morphological and physiological characteristics and MIDI system. B. subtilis J-24 showed antifungal activities against A. alternata(inhibition percentage, 99%), Botrytis cinerea, Phytophthora capsici, Pythium ultimum, Colletotrichum gloeosporioides, Stemphylium botryosum. The growth of red pepper seedling was promoted as compared to control when the microbial inoculants was mixed in bed soil. In the mixed microbial inoculants bed soil, the leaf area of red pepper was increased of 15 percent, the hypocotyl weight 12 percent, the root length 12 percent, total dry weight 13 percent as compared to those grown in the general bed soil.

• Research in Plant Disease
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• v.8 no.4
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• pp.224-227
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• 2002

From the necrotic stem of aquaculture Dracaena for living room decoration, we observed conidia on acervuli with occasional setae and perithecia in vivo. Morphological characters were; acervuli, dark brown and 300-500 ${\mu}{\textrm}{m}$ in diameter; conidia, hyaline, aseptate, cylindrical to slightly ellipsoid with rounded apex and narrow truncate base on phialidic conidiophores, 12.5-17.5 ${\mu}{\textrm}{m}$; setae, variable in length 1-4 septate, slightly swollen at the base and tapered to the apex, 200 ${\mu}{\textrm}{m}$; appressoria, dark brown ovate to obovate irregular 5-12.5 ${\mu}{\textrm}{m}$, perithecia on decayed stem, globose, dark brown and black 85-300 ${\mu}{\textrm}{m}$; asci 8 spored, clavate to cylindrical; 50-62.5$\times$8-10 ${\mu}{\textrm}{m}$; ascospores, oval to fusiform, sometimes slightly curved, aseptate, hyaline. Above characteristics were also confirmed in vitro. Colletotrichum state of this fungus was also compared with C. lindemuthianum and C. musae in terms of morphology of conidia and setae and growth on PDA etc. This fungus was identified as Glomerella cingulata(Stonem.) Spaulding & Schrenk(Colletotrichum gloeosporioides(Penz. Sacc.).

• Research in Plant Disease
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• v.12 no.1
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• pp.46-50
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• 2006

The microorganisms with the antifungal activity against Phytophthora capsici and Colletotrichum acutatum and the plant growth-promoting activity were screened from a forest and natural fields of Gajang-Dong, Sangju-city. One of the isolates, Streptomyces griseofuscus 200401, was selected as a good plant growth-promoting strain in this study. In greenhouse test, the number of leaf, fresh weight, and dry weight of pepper plants, that were grown with treatment of culture suspension or powder containing S. griseofuscus 200401, were higher than those without the bacterial cells. Cultivation of S. griseofuscus 200401 strain for 7 days in a nutrient rich medium produced ammonium chloride up to 0.13 ${\mu}g/ml$ in the culture solution of S. griseofuscus. Treatment of the selected strain significantly reduced the severity of the late blight of pepper plants to show the equivalent disease control activity to chemical fungicide. This study suggests that S. griseofuscus 200401 strain could be a potential biological agent with the biocontrol activity and the plant growth-promoting activity.

• Korean Journal of Agricultural Science
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• v.20 no.1
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• pp.18-24
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• 1993

This experiment was focused on determining the potential of sodium hypochlorite (NaOCl) as fungicide against seed-borne fungi. Effects of NaOCl to control seed-borne fungi were compared to the those of Benlate T in several crop seeds. 1. The effect of NaOCl on disinfection of sesame seeds without imparing germination was highest in the range of 1-2% solution for 10 min. Also, a 30 min immersion of rice seed in 1-2% solution reduced incedence of seed-borne fungi. 2. Alternaria spp. in seeds of radish and chinese cabbage and Colletoricum spp. in pepper were significantly reduced by a 10 min immersion of seeds in 1% NaOCl. 3. The effective control range of NaOCl for seed-borne fungi was much wider than that of Benlate T in sesame seeds. No clear difference between chemicals was found in rice seeds. However, germination of seeds were impaired at 1-2% NaOCl immersion for more than 1 hour.

• Korean Journal of Medicinal Crop Science
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• v.19 no.3
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• pp.198-204
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• 2011

This study was performed to enhance antifungal activity of anthracnose in chili pepper by nanopaticles of thiamine di-lauryl sulfate (TDS) through high pressure homogenization process. Yield of TDS was 79.14% by reaction of thiamine hydrochloride and sodium lauryl sulfate. TDS nanopaticle solution was manufactured through high pressure homogenization process. The turbidity of nanoparticles solution was increased with increasing the concentration of TDS, and nanoparticles solution of 100 ppm was showed the highest turbidity with absorbance of 3.212. The size of nanoparticles solution was measured as average 258.6 nm by DLS. Nanoparticles solution of 100 ppm showed growth inhibition activity with higher than about 80% compared to the control group against Colletotrichum gloeosporioides. Finally, nanoparticles solution was increased effectively the penetration of the TDS nanopaticles on attached cell membrane of hyphae and started to destruct the cells under microscope observation. Consequently, we suggested that the TDS nanoparticle solution by high pressure homogenization process might be suitable biochemical pesticides for improving the antifungal activities against anthracnose in pepper.

• Journal of Mushroom
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• v.19 no.4
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• pp.272-278
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• 2021

Bacillus velezensis HKB-1 was isolated from the composted spent mushroom substrate of Lentinula edodes (LeCSMS) and inhibited mycelial growth of phytopathogenic fungal species, Phythhopthora capsici, Collectotrichum coccodes and Fusarium oxysporium by more than 70%. B. velezensis HKB-1 showed bacterial growth rate 10 to 100 times higher than that of other commercial bacterial media in water extract of LeCSMS supplemented with 1% molasses. The LeCSMS medium was effective in promoting the growth of pepper and controlling Phytophthora blight disease of pepper.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.280-286
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• 2009

To investigate anti-phytopathogenic fungal activity of Coptis chinensis, the methanol extract and its organic solvent fractions were prepared. Using the extract and the fractions, in-vitro spore-germination inhibition and mycelial-growth inhibition activities were evaluated against Colletotrichum gloeosporioides, Phytohpthora capsici, Pyricularia grisea, Rhizoctonia solani, Botryosphaeri dothidea, Glomerella cingulata, respectively. Treatment of the methanol extract (500 mg/mL) into the spore of phytopathogenic fungi completely inhibited germinations for 5 days, except B. dothidea, and showed strong antifungal activities against P. grisea and B. cinerea, and antioomycetes activity against P. capsici. The minimal growth inhibition concentrations of the methanol extract against P. grisea, B. cinerea and P. capsici were 300, 300, and 500 mg/mL, respectively. For practical application of C. chinensis in red-pepper field, the hot-water extract (1,000 mg/mL) was prepared in commercial facility, after evaluation of heat stability and solvent-extraction yields of antifungal substances. The 3-times leaf-spray of the extract from June to August, 2008 did not show any deleterious effect to red-pepper. In fact, the leaf-spray promoted plant growth including leaf, root and fruit. The average weight and rind of each fruit were increased to 119% and 117% comparison to those of without treatments. Our results suggest that C. chinensis is a useful source for control of red-pepper diseases and plant growth.

• Korean Journal of Environmental Agriculture
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• v.35 no.3
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• pp.191-201
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• 2016

BACKGROUND: The aim of this study was to investigate the antimicrobial effects of the ethanol extracts from various medicinal herbs against plant pathogens to understand the possible the crop protection agents.METHODS AND RESULTS: Among the tested medicinal herbs, Zizyphus jujuba ethanol extract had the potent antimicrobial activity against Phytophthora capsici, Erwinia carotovorum subsp. carotovora, Pseudomonas syringae pv. syringae and Ralstonia solanacearum. The major constituents of Z. jujuba were identified to eugenol(40.45%), dodecanoic acid(18.40%), β-caryophyllene (10.05%) and isoeugenol(9.85%) by GC/MS. Eugenol and isoeugenol had strong inhibitory activity on spore germination against P. capsici and growth against E. carotovorum subsp. carotovora, P. syringae pv. syringae and R. solanacearum.CONCLUSION: In this regard, eugenol and isoeugenol were found to be responsible for the antimicrobial activity of Z. jujuba ethanol extract against plant pathogens. In addition, Z. jujuba ethanol extract, eugenol and isoeugenol can be used the potent antimicrobial agents.