• The Korean Journal of Mycology
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• v.48 no.4
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• pp.397-405
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• 2020

Beech mushroom (Hypsizygus marmoreus) is one of the most popular mushrooms in Japan, China, and Korea because of its delicious taste, nutritious value, and unique crunchy texture. In 2018-2019, unusual signs on the mushroom were observed in mushroom farms in Gyeongnam Province. The main signs were the inhibition of mycelial growth and primordial formation on the surface of mushroom media. When green mold caused contamination at early stage, the rate of pinhead formation by the mushroom greatly decreased to 46.5-71.5%. Conidia of the causal green mold were ellipsoidal, dark green, and measured 2.0-3.1㎛ long. The optimum temperature for mycelial growth of the green mold was 25℃. The phylogenetic tree obtained from the internal transcribed spacer (ITS) rDNA sequences showed that the isolated green mold corresponded to Penicillium brevicompactum (100.0%). This is the first report of green mold contamination caused by P. brevicompactum on H. marmoreus.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.149-153
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• 2017

Contamination and growth of Trichoderma, a green mold, on the oak log and wooden chip or sawdust media can severely inhibit the growth of oak mushroom. Chemicals including pesticides and antibiotics are generally not allowed for the control of green mold disease during mushroom cultivation. In this study, bacterial pathogens causing blotch disease on the oyster mushrooms were isolated and their peptide toxins were purified for the control of green mold disease. Strains of Pseudomonas tolaasii secret various peptide toxins, tolaasin and its structural analogues, having antifungal activities. These peptides have shown no effects on the growth of oak mushrooms. When the peptide toxins were applied to the green mold, Trichoderma harzianum H1, they inhibited the growth of green molds. Among the 20 strains of peptide-forming P. tolaasii, strong, moderate, and weak antifungal activities were measured from 8, 5, and 7 strains, respectively. During oak mushroom cultivation, bacterial culture supernatants containing the peptide toxins were sprayed on the aerial mycelia of green molds grown on the surface of sawdust media. The culture supernatants were able to suppress the fungal growth of green molds while no effect was observed on the mushroom growth and production. They changed the color of molds from white aerial mycelium into yellowish dried scab, representing the powerful anti-fungal and sterilization activities of peptide toxins.

• The Korean Journal of Mycology
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• v.37 no.2
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• pp.144-149
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• 2009

The occurrences of the major diseases and the densities of air-born microbes were surveyed in the cultivation facilities for oyster mushroom (Pleurotus ostreatus), king oyster mushroom (Pleurotus eryngii), and enoki mushroom (Flammulina velutipes) in different areas of Korea. Green mold disease was most often developed in oyster mushroom bed cultivation with the disease incidence rate of approximate 10% while the disease incidences from bottle and plastic envelop cultivation were less than 1~2%. In the bed cultivation, the major air-born microbes in the growth room were Aspergillus, Penicillium, Trichoderma, and Curvularia with the total fungal population density of 567~1,297 CFU/$m^3$ . However, only Trichoderma and Penicillium were detected in the growth rooms and innoculation rooms of bottle and plastic envelop cultivation with the densities of 350~700 CFU/$m^3$ and 160~260 CFU/$m^3$, respectively. The bacterial diseases become evident in the growth rooms of bottle and plastic envelop cultivation with the approximate incidence rate of 10%. The identified bacterial species were Brevibacillus levelkil, Rhizobium radiobacter, Brevundimonas vesicularis, Pseudomonas mosselii, Microbacterium testaceum. Sphingomonas panmi, Sphingomonas yabuuchiae, Paracocus dinitrificans, Curtobacterium flaccumfaciens pv. flaccumfaciens and some unidentified bacteria with the densities of 40~6,359 CFU/$m^3$ in the growth rooms and 9 CFU/$m^3$ in the inoculation room. This study indicated that the green mold disease by fungal strains was the major mushroom disease in the bed cultivation and suggested that the contamination of bacteria and fungi together in the growth media could result in severe production loss. The plastic envelope and bottle cultivation were evidenced to be less susceptible to such contaminations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.4924-4931
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• 2011

This research performed to evaluate a production processes reporting by the HACCP system of green vegetable juice products, containing lactic acid bacteria, stage of processing raw materials agricultural products and production facilities of general bacteria and pathogenic micro organism. General bacteria are found from four samples of storage of agricultural products at process stage and water was detected 8.67~14.67 CFU/ml. However, all samples were detected less than 105 CFU/ml as a legal standards after the process of UV sterilization. For the outcome of experiment of E.coli, E.coli O157:H7, B.cereus, L.moonocytogenes, Salmonella spp, Staph.aureus as the food poisoning bacterial, E.coli was detected until UV pre-step process in storage process and B.cereus was detected partly till 1st washing. Since all bacterial, Yeast and Mold are detected in main materials, pre-control method is a necessary to establish for decreasing with a number of initial bacteria of main materials and it is considered to establish the effective ways of washing and sterilization such as production facilities for cross contamination prevention of bacteria and Sthaphylococcus. Based on above results, the process of UV sterilization should be managed with CCP as an important process to reduce or eliminate the general and food poisoning bacterial of green vegetable juice products, including lactic acid bacteria. Therefore, it is considered to need an exhaustive HACCP plan such as control manual of UV sterilization, solution method, verification, education and training and record management.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.265-272
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• 2019

The purpose of this study was to investigate the effects of LED and QD-LED (Quantum Dot) irradiation on seed germination, antioxidant ability, and microbial growth, during red radish (Raphanus sativus L.) sprouts cultivation. Irradiated light was blue, red, blue + red and blue + red + far red (QD-LED) lights, and the controls were a fluorescent lamp (FL), and dark condition. Germination rate of red radish was highest in the dark condition. The plant height and fresh weight of red radish sprouts that irradiated each light for 24 hrs after 7 days growing in dark condition, did not shown significantly difference among treatments. After 24 hrs of light irradiation, cotyledon green was best in blue + red light, and the red hypocotyl was excellent in blue light and QD-LED light. DPPH and phenol contents were high in dark and blue + red light treatment, and anthocyanin content was high in blue light and QD-LED light. Total aerobic counts were similar in all treatments and did not show bactericidal effect, whereas E. coli count was lowest in QD-LED light treatment, and yeast and mold counts were lowest in FL only treatment. Results suggest that when red radish seeds were germinated in dark condition and cultivated for 7 days as sprouts, and then treated with blue light or QD-LED light for 24 hrs, the seeds produced good quality red radish sprouts with greenish cotyledon, reddish hypocotyl, high anthocyanin content, and lower level of E coli contamination.