• Journal of Food Hygiene and Safety
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• v.7 no.1
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• pp.1-6
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• 1992

Two Rice cultivars , a high yield variety of Cheongcheong and a Korea native kind of Chucheong were grown in paddy. 1$\mu\textrm{g}$ and 10$\mu\textrm{g}$ of aflatoxin B1 and Aspergillus flavus (106 conidia/ml) were inoculated at milk stage. At harvest, kernels from the inoculated plant showed slightly lower ripening rates and 100-grain weight than did those of controls. The nutrient and fatty acid composition of unpolished rice of inoculated group were similar to those of controls and difference between the control and inoculated group were not significantly different.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.181-184
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• 2004

This study was conducted to investigate the adequate irradiation dose to eliminate harmful fungi inoculated if beef jerky with a 10% higher moisture content and improved textural property. Aspergillus flavus (approximately $10^6\;CFU/cm^2$) was tested in broth, spore suspension, and inoculated jerky. $D_{10}$ values of A. flavus were 0.36 kGy in the broth and suspension, and 0.47 kGy in the jerky. The results indicate that gamma irradiation can be effectively used to control the fungus growth in beef jerky with an improved quality and higher moisture content.

• The Korean Journal of Mycology
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• v.51 no.3
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• pp.219-227
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• 2023

This study was conducted to analyze the distribution and characteristics of fungal species in meju using the traditional method. Fungal distribution in meju was investigated using metagenomic and morphological analyses, based on which Aspergillus flavus/oryzae strains were identified as the dominant fungi in all meju samples, followed by Pichia, Rhizopus and Lichtheimia spp. As A. flavus/oryzae was dominant, we further evaluated the aflatoxin production ability and enzymatic activity of the isolates. Thin-layer chromatography and polymerase chain reaction revealed that the A. flavus/oryzae strains isolated from meju are non-aflatoxigenic fungi. Based on the analyses of amylase and protease activities, strains with high activities of amylase or protease were identified, which are proposed to be used as starters for meju fermentation.

• The Korean Journal of Mycology
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• v.43 no.3
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• pp.200-205
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• 2015

Perilla frutescens var. japonica Hara was collected from farmland in Seongju-gun. Fifteen endophytic fungal strains with different colony morphologies were isolated from roots of P. frutescens. Waito-c rice seedlings were treated with the concentrated culture filtrates (CF) of endophytic fungi for observation of their plant growth-promoting activities. In the results, the CF of Y2H001 fungal strain promoted the growth of the waito-c rice seedlings. The phylogenetic tree of Y2H001 strain was analyzed by the combined sequences of the partial internal transcribed spacer region (ITS) and partial betatubulin gene. Molecular and morphological studies identified the Y2H001 strain as belonging to Aspergillus flavus. In gas chromatography mass spectrometry (GC/MS) analysis of the CF of Y2H001 strain, gibberellic acid (GA) was detected and quantified. Therefore, we describe Y2H001 strain as a new $GA_3$-producing A. flavus based on morphological, molecular characteristics and analysis of secondary metabolite.

• Mycobiology
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• v.31 no.4
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• pp.191-195
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• 2003

Ethanol treatment method was attempted for the selective isolation of ethanol-tolerant fungi from two sites of rice paddy fields around Seoul area. The vertical and seasonal fluctuation of the fungal population were also investigated. The ethanol-tolerant fungi were Talaromyces stipitatus, T. flavus var. flavus, T. helicus var. major, Eupenicillium javanicum, Emericellopsis terricolor, Pseudourotium zonatum, Aspergillus flavus, Cladosporium cladosporioides, Penicillium frequentans, P. janthinellum, and P. verruculosum. The most dominant species isolated by this method was T. stipitatus. It was found that the numbers of fungal species and colony forming units(CFUs) of ethanol-tolerant fungi were higher in Ascomycota than in Deuteromycota. A particular tendency appeared the highest CFUs in autumn, but lower in spring and winter. T. stipitatus was the dominant species of ethanol tolerant microfungi. This result would suggest that membrane lipid composition of ethanol-tolerant fungi isolated from the soils may play on important role in the ethanol tolerance.

• Applied Biological Chemistry
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• v.7
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• pp.67-77
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• 1966

For the production of proteolytic enzyme wilth Aspergillus, the examination is made on the culture-time and koji extracting conditions, during producing koji. 1. The highest activity showed up when the culture-time took 50 hours for Aspergillus sojae and 60 hours for Aspergillus flavus. 2. When the cultured koji was extracted by a buffer solution and water, the former gave the product of higher activity until pH 7 through pH 12, and water until pH 3 through pH 7. 3. In the method of crushing and granule extractions, crushing extraction produced the one of higher activity than granule. 4. The highest activity showed up when Aspergillus sojae took 5 hours (Aspergillus flavus 4 hours) in the time of extracting enzyme solution. 5. The highest activity showed up when both Aspergillu sojae and Aspergillus flavus reacted and indicated $37.60^{\circ}C$ in the reaction temperature and activity.

• The Korean Journal of Mycology
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• v.20 no.3
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• pp.252-258
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• 1992

Thirty three species and two species varieties belonging to 14 genera of fungi were collected from 20 cowpea cultivars on glucose Czapek's agar (11 genera and 25 species+1 var.) and glucose-Czapek's agar supplemented with 10% NaCl (7 genera and 18 species+2 var.) at $28{\pm}2^{\circ}C$. The total count of fungi were 6716 colonies/g in all cowpea cultivars. On glucose-Czapek's agar and identified; Aspergillus flavus, A. niger, A. sydowii, A. flavus var. columnaris, A. terreus, Penicillium chrysogenum, Emericella nidutans and Rhizopus stolonifer. The total count of halotolerant or halophilic fungi was 3515 colonies/g on 10% NaCl-glueose-Czapek's agar and identified; the most common species were: A. flavus, A. sydowii, A. tamarii A. flavipes, A. niger, A. flavus var. columnaris, A. ochraceus, A. oryzae and P. chrvsogenusm. Thin layer chrormatographic analysis of chloroform extracts of the different seed samples revealed that four cultivars were naturally contaminated with aflatoxins $B_1,\;B_2,\;G_1$ and $G_2$, $(45-112\;{\mu}g/kg)$.

• 한국균학회소식:학술대회논문집
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• 2014.05a
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• pp.25-25
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• 2014

Koji molds are comprised of yellow, black and white. Black and white koji molds were recently re-visited by this author and it is concluded that they consists of Aspergillus luchuesnsis, A. niger and A. tubingensis, and the most important species for alcoholic beverage production is A. luchuensis. In the case of yellow koji mold, it is comprised of Aspergillus oryzae, A. sojae and A. tamari. In the case of A. sojae, the species is scarcely isolated from nature and rarely used for industry in Korea. Aspergillus tamari is often isolated from traditional Korean Meju, a fermented soybean product, and the classification of the species is clear. However, in the case of A. oryzae, differentiation between A. oryzae and A. flavus is still in controversy. In this study, we collected 415 strains of Aspergillus flavus/oryzae complex from air, rice straw, soybean, corn, peanut, arable soil and Meju in Korea and we examined the aflatoxin producing capacity of the strains. The norB-cypA, omtA and aflR genes in the aflatoxin biosynthesis gene cluster were analyzed. We found that 367 strains (88.4%) belonged to non-aflatoxigenic group (Type I of norB-cypA, IB-L-B-, IC-AO, or IA-L-B- of omtA, and AO type of aflR), and only 48 strains (11.6%) belonged to aflatoxin-producible group (Type II of norB-cypA, IC-L-B+/B- or IC-L-B+ of omtA, and AF type of aflR). In the case of A. flavus/oryzae strains from Meju, almost strains (178/192, 92.7%) belonged to non-aflatoxigenic group and only 14 strains (7.3 %) belonged to aflatoxin-producible group. It is proposed in this study that non-aflatoxigenic strain from Meju is classified as A. oryzae, considering that Meju is food material.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.721-725
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• 1989

Aflatoxin accumulation by Aspergillus flavus in rice was inhibited by A. kawachii and A. Shirousamii so that the rate of toxin accumulation and the maximum concentration of accumulated aflatoxins were considerablly reduced, although the initiation of aflatoxin accumulation was not affected. The maximal accumulated aflatoxin $B_1$ in rice by A. flavus at $28^{\circ}C$ and 85% RH was $40{\mu}g/50g$ rice after 35 days. Under the same condition but the additional inoculation of A. kawachii, $25{\mu}g\;of\;aflatoxin\;B_1$ was accumulated maximally in 50g rice after 45 days. When A. shirousamii was inoculated simultaneously with A. flavus on rice, however, only trace levels of aflatoxins were detected throughout 60 days of storage. Aflatoxins added to rice were reduced by 97% with A. kawachii and by 98% with A. shirousamii after 7 days during rife koji preparation. They were also reduced after 48 Hours of incubation by 30-67%, with A. kawachii koji and by 16-75% with A. shirousamii koji.

• The Korean Journal of Malacology
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• v.31 no.4
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• pp.323-326
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• 2015

Three species of Ellobiid molluscs collected from Korea were identified as Auriculastra duplicata (Pfeffer, 1854), Laemodonta siamensis (Morelete, 1875) and Melampus (Pira) flavus (Gmelin, 1791). This is the first record from the Korea, providing a description of the species with illustration for the shell morphology. Including the new recorded in this study, the family Ellobiidae contained six genera and 13 species in the Korea.