• The Korean Journal of Mycology
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• v.41 no.2
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• pp.118-126
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• 2013

The experiment was carried out to analyze the inhibition effect of plant pathogenic fungi and growth promotion activity induced by the bacterial strains isolated from peatmoss. Among the isolated bacterial strains, B10-2, B10-4, B10-5 and B10-6 which showed more than 30% inhibition rate against Botrytis cinerea and Rhizoctonia solani in vitro, were further analyzed in the greenhouse for the growth promotion activity on lettuce (Lactuca sativa), pak-choi (Brassica compestris L. ssp. chinensis) and Chinese cabbage (Brassica campestris L. ssp. pekinensis). The results showed the treatment of B10-4 on lettuce showed the highest growth promotion activity with the leaf area ($169.17cm^2$), fresh weight (leaf: 40.29 g, root: 8.80 g)and dry weight (leaf: 11.24 g, root: 4.17 g), which was about two folds as compared to control. On pak-choi, the growth promotion rate was the highest with the leaf area of $112.87cm^2$, leaf fresh weight of 60.70 g, root fresh weight of 3.37 g, leaf dry weight of 14.34 g, and root dry weight of 1.90 g. As a result of treatment of B10-13 on chinese cabbage, the growth promotion rate was the highest with the leaf area ($293.56cm^2$), fresh weight (leaf: 113.67 g, root: 2.40 g) and dry weight (leaf: 6.03 g, root: 0.53 g). The production of Indole Acetic Acid (IAA) and Indole-3-Butylic Acid (IBA) were also analyzed in these bacterial isolates. The IAA and IBA analyses were carried out in all bacterial isolates each day within the 5 days of incubation period. The highest production of IAA was observed with $112.57{\mu}g/mg$ protein in B10-4 after 3 days of incubation and IBA production was the highest in B10-2 with $58.71{\mu}g/mg$ protein after 2 days of incubation. Also, phosphate solubilizing activity was expressed significantly in B10-13 in comparison to that of other bacterial isolates. Bacterial identification showed that B10-2 was Bacillaceae bacterium and B10-5 was Bacillus cereus, B10-4 and B10-6 were Bacillus sp. and B-13 was Staphylococcus sp. by ITS sequence.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.319-327
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• 1993

The objectives of this study were to isolate ectomycorrhizal fungi associated with roots of Pinus rigida ${\times}$ P. taeda trees planted in Chonbuk and Daejon locations and to identify them, and to observe the morphology of mycorrhizae formed by the isolated fungi. Pinus rigida ${\times}$ P. taeda seedlings formed ectomycorrhizae with Rhizopogon rubescens, Rhizopogon sp. and Suillus pictus isolated from the roots of mature Pinus rigida ${\times}$ P. taeda trees, Pinus rigida ${\times}$ P. taeda seedlings formed ectomycorrhizae with Pisolithus tinetorius too. The root surface of inoculated seedlings was covered with mycelia, and Hartig net were well developed in those roots. The size of vacuole was small, and the protoplasm was planty in ectomycorrhizal cell, compared to nonmycorrhizal cell. But the size of nuclei are not changed even in ectomycorrhizal cell.

• The Korean Journal of Mycology
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• v.9 no.4
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• pp.177-192
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• 1981

From a large number of insects collected by the athours, in Korea. various species of the Laboulbeniales have been obtained Seven species in four genera of these fungi which were found on several beetles of the. families Carabidae, Endomychidae, Staphylinidae are reported as new to Korea. They are as follows: Dichomyces biformis (Host: Philonthus micanticolis), D. furcifer (Host: Philonthus sp.), Enathromyces indicus (Host: Pheropsophus jessoensis), Laboulbenia exigus (Host: Chlaenius varricornis), L. flagellata (Host: Anisodactylus punctatipennis), L. vularis (Host: Bembidion oxyglimma, B. thermarum) and Rickia ancylopi (Ancylopus) melanocephalus). All the specimens studied are deposited in the Biological Laboratory of Educational College, Cho Sun University.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.215-225
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• 2017

Kiwifruit is prone to damage by frost in the harvest season and the occurrence of postharvest diseases. Accordingly, new cultivars overcoming these disadvantages have been developed. Compared to existing cultivars, studies on diseases in new cultivars are very limited. Thus, goal of this study was investigation of fungal infection occurrences in new cultivars. Kiwifruit was harvested in 2014 and 2015 year, respectively. In both years, cvs. Goldone and Redvita showed more resistance against fungal infection but cv. Gamrok was more sensitive compared with cv. Hayward. Major fungi were identified as Botryosphaeria dothidea, Phomopsis sp., Alternaria alternata and Nigrospora sp. Firmness and soluble solids content were also influenced by the occurrences. This study's findings are important for providing practical information on new cultivars in the kiwifruit industry.

• Journal of Microbiology and Biotechnology
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• v.19 no.8
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• pp.760-764
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• 2009

In this study, we investigated the antifungal activity of three different forms of silver nanoparticles against the unidentified ambrosia fungus Raffaelea sp., which has been responsible for the mortality of a large number of oak trees in Korea. Growth of fungi in the presence of silver nanoparticles was significantly inhibited in a dose-dependent manner. We also assessed the effectiveness of combining the different forms of nanoparticles. Microscopic observation revealed that silver nanoparticles caused detrimental effects not only on fungal hyphae but also on conidial germination.

• Journal of the Korean Magnetic Resonance Society
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• v.6 no.1
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• pp.69-77
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• 2002

During the screening of material which has the antimicrobial activity against aminoglycoside-resistant bacteria, A new material $\varepsilon$-(L-$\beta$-Iysine) polypeptide from a culture medium of Streptomyces sp.(DWGS2) was isolated, and the structure and the physicochemical properties of the new material were elucidated. The new material was separated by column chromatography of the culture medium using Dowex1$\times$2, Silica gel, and Sephadex LH20 etc. The chemical structure and molecular weight were determined with the data of various NMR experiments, MALDI mass, and ESI mass experiments. The antimicrobial activity of $\varepsilon$-(L-$\beta$-Iysine) polypeptide is not only better than equal to the activity of known aminoglycoside type of antibiotics(MIC=3.125 - 6.25ug/mL) but also effective against aminoglycoside-resistant bacteria and fungi. If the mechanism of antimicrobial activity against aminoglycoside- resistant bacteria is figured out, the $\varepsilon$-(L-$\beta$-Iysine) polypeptide can be utilized for the treatment of diseases caused by aminoglycoside-resistant bacteria.

• The Plant Pathology Journal
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• v.21 no.3
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• pp.244-251
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• 2005

The induction of growth promotion on numerous crops by rhizobacteria is a well documented phenomenon. In case of tomato (Lycopersicon esculentum), fruit yield is higher in replant soil than that in fresh soil. To investigate what kind of rhizobacterium is involved, microbial community in rhizosphere and on rhizoplane of tomato plants from each soil was analyzed by dilution plating on selective media. Many Gram-negative bacteria and actinomycetes were isolated from tomato in replant soil. One Gram-negative rhizobacterium isolated was identified as Pseudomonas putida based on its biochemical characteristics, fatty acid methyl ester analysis and 16S rDNA sequence. This bacterium designated strain 17 inhibited the growth of Pseudomonas corrugata, and increased growth of tomato seedlings. In addition, its culture filtrate inhibited conidial germination of plant-pathogenic fungi such as Fusarium oxysporum f. sp. radicis-lycopersici, F. oxysporum f. sp. cucumerinum, and Nectria radicicola. Scanning electron microscopy revealed strain 17 colonized and persisted on the epidermal surfaces of tomato radicles and roots. These results suggest that P. putida strain 17 may serve as a biological control agent to suppress multiple soil-borne diseases for tomato plants. Increased microbial populations that suppress deleterious microorganisms including pathogens could be one of the major factors in increased tomato yield in replant soil.

• Journal of Food Hygiene and Safety
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• v.10 no.4
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• pp.263-270
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• 1995

In order to promote the prevention of microbial and enzymatic spoilage and to retain the freshiness, sweet persimmons harvested in Gyeongsangnam-do were treated with graperfruit seed extract(GFSE)-CaCO3 mixture and stored in the proper packaging conditions. A low concentration of GFSE showed effective growth inhibition of plant pathological bacteria and fungi, Enterobacter pyrinus and Fusarium sp., which were involved in the decay of fruits and vegetables. GFSE was stable to heat treatment; its antimicrobial activity was not changed by heat treatment upto 10$0^{\circ}C$. However, when the temperature was raised to 12$0^{\circ}C$, about 90% of total activity was retained within 30 min. GFSE was also highly stable to broad pH changes; its activity was not changed in the range of pH 2.0 to pH 12.0. The physiological function of cell membrane in the spores of Bacillus cereus and the hyphae of Fusarium sp. was destroyed by treating with GFSE. It was observed that treating sweet persimmons with GFSE minxture and storing them in strech-wrapped packages could prolong the greshness of sweet persimmons and reduce quality deterioration.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.235-241
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• 1991

- A phthalic acid derivative and basic macrolide antibiotics, with antimicrobial activity against Gram positive bacteria and phytopathogenic fungi, respectively, were found to be produced by a strain 88-GT-161 identified as being a variety of Streptomyces melanosporofaciens. This paper describes an isolation procedure of the active compounds produced by this strain, their in vitro and in vivo (pot test) antimicrobial activites, and structure determination of one of the compounds, bis (2-ethylhexyl) phthalate, a phthalic acid derivative antibiotic. This compounds, upon cornparision with authentic bis (2-ethylhexyl) phthalate, dioctyl phthalate, revealed a difference in antimicrobial activity even though physico-chemical properties of these two compounds seemed indentical. This is the first report that dioctyl phthalate is biosynthetically produced by a Streptomyces sp. and shows antimicrobial activity.

• Journal of Ginseng Research
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• v.33 no.2
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• pp.139-142
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• 2009

The effect of calcium cyanamide (China-made) soil fumigation on the growth of the ginseng pathogen Rhizoctonia, Pythium), soil microbes, and seed germination of lettuce and radish was investigated. At twice the recommended level (2S0-ppm $CaCN_2$), the growth of Rhizoctonia and Pythium, and the seed germination, were not inhibited. Rather, the effective level was 10,000 ppm. The powder form was more effective than the granular form in inhibiting pathogen growth and seed germination. The lettuce seed was also more sensitive than the radish seed. Calcium cyanamide appearedto decrease the fungi population and to increase Actinomycetes in the soil.