• Korean Journal of Environmental Biology
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• v.21 no.3
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• pp.276-285
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• 2003

To control pythium root rot, Bacillus lentimorbus WJ5a17 with high anti-fungal activity against Pythium ultimum was induced from B. lentimorbus WJ5 by gamma radiation ($^{60}Co$). The biocontrollers of FWJ5 and FWJ5a17 were formulated ($1.0\times 10^{11}$) with B. lentimorbus WJ5 and WJ5a17, respectively, The population density of FWJ5 and FWJ5a17 maintained highly up to $1.0\times 10^{9}$ CFU $g^{-1}$ in nursery and field soils until 30 days after treatment. P. ultimum spores germination were inhibited 71.0% and 81.4% by FWJ5 and FWJ5a17, respectively. Pythium root rot of yea pepper, Chinese cabbage and radish were significantly (p < 0.05) controled by one time treatment of FWJ5 and FWJ5a17.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.379-386
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• 1998

Deterioration of food is in general caused by the presence of microorganisms and chemical compounds of food itself. There exists antimicrobial compound in the food, however, addition of food antiseptics, additives, or physico-chemical processing is a common practice. The safety of artificial chemical antiseptics became a serious public concern, therefore, new natural antiseptic compounds are in need to be developed. We have isolated a new natural antifungal protein (KBS-B2) from Astragal seed through ammonium sulfate precipitation and column chromatography using FPLC Mono-S and Superose 12HR. The purified protein inhibited growth of Candida albicans, and spore germination of food spoiling fungi such as Aspergillus ochraceus, Penicillium expensum, P. digitatum and Botrytis cineria. Antifungal effect of the KBS-B2 protein could be directly assayed by bioautography overlaying the fungal spores on the electrophoresed acrylamide gel. The comparison of N-terminal amino acid sequences of the KBS-B2 with known antifungal protein revealed that had 50% homology to thaumatin and zeamatin like proteins.

• Mycobiology
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• v.32 no.2
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• pp.88-94
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• 2004

Protoplasts of the wild type strain of Pleurotus osteatus were mutagenized with UV light, and 3,000 colonies were examined for abnormal mycelial and fruiting phenotypes. Forty one strains displayed variant phenotypes in mycelia and fruiting processes. The variant phenotypes were classified into 6 groups: (1) auxotrophic strains, which are incapable of growing on minimal media and can only grow when provided with their specific requirements; (2) abnormal vegetative strains, which grow very slowly on minimal and complete media; (3) primordiumless strains, which fail to develop to the formation of primordia; (4) maturationless strains, which form primordia, but do not form mature fruiting bodies; (5) specifically colored strains, which have Specific bluish grey or bluish white pileus; (6) poorly spored strains, which fail to produce basidiospore or which produce few spores. These variant strains may be useful in genetic breeding programs and for the studies of fungal development and genetics.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.674-683
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• 2019

Some species of the Trichoderma genus are reported as the major problem in oak wood mushroom production in Korea. In spite of economic loss by the fungi, scientific information on airborne Trichoderma species is not much available. To generate information for disease management development we analyzed airborne Trichoderma. A total of 1,063 fungal isolates were purely obtained from indoor air sampling of cultivation houses used for oak wood mushroom using sawdust media. Among the obtained isolates, 248 isolates were identified as Trichoderma fungi including T. harzianum, T. atroviride, T. citrinoviride, and T. pseudokoningii, by morphological and molecular analysis. T. harzianum was dominant among the four identified species. All the four Trichoderma species grew fast on solid nutrient media tested (potato dextrose agar [PDA], malt extract agar [MEA], Czapek's Dox + yeast extract agar [CYA] and cornmeal dextrose agar). Compact mycelia growth and mass spore production were better on PDA and CYA. In addition, T. harzianum and T. citrinoviride formed greenish and yellowish mycelium and spores on PDA and CYA. Greenish and yellowish pigment was saturated into PDA only by T. pseudokoningii. These four Trichoderma species could produce extracellular enzymes of sawdust substrate degradation such as β-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease. Their mycelia inhibited the growth of oak wood mushroom mycelia of two tested cultivars on dual culture assay. Among of eleven antifungal agents tested, benomyl was the best to inhibit the growth of the four Trichoderma species. Our results demonstrate that the airborne Trichoderma fungi need to be properly managed in the cultivation houses for safe mushroom production.

• The Plant Pathology Journal
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• v.36 no.2
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• pp.133-147
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• 2020

Hexanal, a C-6 aldehyde has been implicated to have antimicrobial properties. Hence, this study was conducted to determine the antifungal activities of hexanal vapor against major postharvest pathogens of banana viz., Colletotrichum gloeosporioides and Lasiodiplodia theobromae. The pathogens were cultured in vitro and exposed to hexanal vapor at 600, 800, 1,000 and 1,200 ppm. Mycelial growth of both fungal pathogens were inhibited completely at 800 ppm and the incidence of anthracnose and stem-end rot diseases reduced by 75.2% and 80.2%, respectively. The activities of peroxidase, polyphenol oxidase, phenylalanine ammonia-lyase and glucanase had transiently increased in hexanal vapor treated banana by 5 to 7 days and declined thereafter. Postharvest treatment of banana with hexanal vapor resulted in phospholipase D inhibition and also resulted in cell wall thickening of the treated fruit, which impeded the penetration of the pathogenic spores. This was further confirmed by scanning electron micrographs. The defense-related protein intermediaries had increased in hexanal vapor treated banana fruit, which suggests induced resistance against C. gloeosporioides and L. theobromae, via., the phenylpropanoid pathway which plays a significant role in hindering the pathogen quiescence. Delayed ripening due to inhibition of phospholipase D enzyme, inhibition of mycelial growth and induced systemic resistance by defense enzymes collectively contributed to the postharvest disease reduction and extended shelf life of fruit.

• Journal of Mushroom
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• v.18 no.1
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• pp.84-90
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• 2020

Wild-type isolates of H. erinaceus were collected from different geographical areas of Korea. Nineteen isolates were cultured on mushroom substrate for producing fruiting bodies. Of these, 14 isolates formed pinheads and fruiting bodies on the substrate. The morphological and cultivation characteristics of fruiting bodies were categorized by pinheading, fruit body formation, spine types, fresh weights, and colors. Microstructures, including spines, spores, and basidia on the fruiting bodies were observed using scanning electron microscopy. The H. erinaceus isolates demonstrated different PCR polymorphisms produced by universal fungal primers (UFPs) and were classified into four groups based on their high genetic diversity.

• Research in Plant Disease
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• v.11 no.2
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• pp.204-207
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• 2005

A Rhizopus soft rot caused by Rhizopus stolonifer occurred on Momordica charantia at Daesan-myon, Chang-won city, Gyeongnam province from 2003 to 2005. The disease usually started from wound on fruit with water-soaking lesions. The lesion rapidly expanded and softened. The fungal mycelia grew vigorously and sporangia, sporangiophores, and stolons were formed on surface of the fruit. Spoyangiophores were $15\~30{\mu}m$ in width. Sporangia were globose or hemispheric and $90\~180{\mu}m$ in size. The color of sporangia was white and cottony at first and turned to brownish black with many spores at maturity. Columella were hemispheric and $80\~150{\mu}m$ in size. Sporangiospores were irregular round or oval, brownish-black streaked and $7\~18{\times}6\~12{\mu}m$ in size. The optimum temperature for mycelial growth of the fungus on PDA was $25^{\circ}C$. On the basis of mycological characteristics and pathogenicity to host plants, the causal fungus was identified as Rhizopus stolonifer (Ehrenberg ex. Fr,) Lind. This is the first report of Rhizopus soft rot on M. charantia caused by R. stolonifer in Korea.

• Research in Plant Disease
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• v.7 no.2
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• pp.120-122
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• 2001

The powdery mildew of broad bean (Vicia faba) extensively occurred in farmers' fields in Changseon-myon, Namhae-gun, Gyeongsangnam-do, Korea in 2001. Both sides of the leaves and stems were covered with white fungal spores and mycelia, and then the leaves and stems colored brown and dark brown and eventually died. Conidia and conidiophores were formed on the lesion. Conidia were cylindric, 29~45$\times$13~23 um (av, 36~18 um) in size and born singly on the conidiophore. Fibrosin bodies were not observed. Conidiophores were straight with 3-4 cylindric cells and 51~100$\times$6~10 um (av.70$\times$8 um) in size. Foot cell was 28~53$\times$7~10 um (av,39$\times$8 um) in size. Appressorium was a lobed type. Cleistothecia were not formed. This is the first report on powdery mildew of broad bean caused by Oidium sp. in Korea.

• Journal of the Korean Society of Safety
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• v.21 no.2 s.74
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• pp.150-157
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• 2006

Sick Building Syndrome (SBS) is an illness symptom such as irritation of eyes, skin eruption and vomit ing in newly constructed buildings. It is mainly due to the harmful gases from the materials installed in building such as Volatile Organic Compounds (VOCs), Semivolatile Organic Compounds (SVOCs), floating bacteria, fungi, fungal spores and viruses, human bioeffluents in many modem buildings. The general ways to improve the Indoor Air Quality (IAQ) are ventilating, utilizing eco-material without harmful gases and reducing or removing harmful gases through additional treatment to the building materials. This study aimed to improve the Indoor Air Quality(IAQ) by applying surface coating on the building materials and to make safe living environments through the analysis of air quality before and after surface coating treatment in buildings.

• The Korean Journal of Mycology
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• v.31 no.1
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• pp.50-52
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• 2003

The powdery mildew of Phlox (Phlox paniculata) extensively occurred in the experimental farm of Cheongam-myon, Hadong-gun, Gyeongnam province in 2002. Both sides of the leaves and stems were covered with the white fungal spores and mycelia, and then the leaves became brown to dark brown in color, eventually died. The conidiophores on the lesion were observed. Conidia were cylindric in shape, colorless, $25.3{\sim}49.4{\times}12.3{\sim}17.2{\mu}m$ in size and borne singly on conidiophore. Fibrosin bodies were not observed. Conidiophores were straight with 2-4 cylindric cells, and $65.7{\sim}124.8{\mu}m$ in size. Appressoria were lobed. Cleistothecia were not formed. This is the first report on powdery mildew of Phlox caused by Oidium sp. in Korea.