• Journal of Food Hygiene and Safety
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• v.4 no.3
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• pp.165-170
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• 1989

To isolate the aflatoxin producing strains from agricultural products in Youngnam districts, rice(59), meju(30), corn(32), barley(58), soil(33), peanut(30), soybean(45), and unhulled barley(60) were collected from markets or homes. From 342 sample sources, 280 strains of Aspergillus spp. were isolated. As a result of screening by TLC, 29 strains expressed fluorescent spot and four strains have a same Rf value of standard aflatoxins, and the percentage of contamination from aflatoxin producing strains was 1.3%, and those strains were estimated as Aspergillus flavus group by the examine of characteristics and morphology.

• Korean Journal of Microbiology
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• v.20 no.2
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• pp.80-88
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• 1982

Soil microfungi of the paddy fields in Korea were isolated by the dilution plate method from soil samples of two selected sites. It was concluded that 14 species among 30 species identified were undescribed fungi in Korea. Among them, 7 species of Ascomycetous fungi were described in this paper as new to Korea. Species of the genus Talaromyces were found to be dominant in paddy field soils and they consisted of Talaromyces flavus var. flavus, T. panasenroi, T.stipitalus and T.trachyspermus. Special attention was paid on the predominant occurrance of Westerdyrella multispora which produced globose to subglobose pseudothecia containing 32 spored asci with multiseptate, cylindrical ascospores. A cellulose decomposing ascomycete, Chaetomium globosum, was also found which produce black, ostiolate perithecia furnished with numerous, wavy to undulate terminal hairs. They contain evansecent, clubshaped, 8 spored asci with lemon-shaped, olive brown ascospores. Another ascomycte, Emericellopsis terricola with Acremonium anamorph, waas isolated from two sites.

• Mycobiology
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• v.34 no.4
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• pp.180-184
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• 2006

The mycobiota of 160 hair and nail samples collected from 4 different governorates in upper Egypt were estimated using soil plate method for isolating keratinophilic and dermatophytic fungi. Twenty-three fungi were recorded on both hair and nail samples collected from the four governorates. Highest fungal diversity (20) was collected from Red Sea samples followed by Qena (18) and Aswan (17) while lowest fungal diversity was recorded from Sohage samples. The common genera were Aphanoascus, Aspergillus, Penicillium, Paecilomyces and Chrysosporium. The most prevalent species belonging to these genera were: A. fulvescens, Aphanoascus sp. A. flavus link, A. flavus var. columnaris, P. chrysogenium. P. lilacinus and C. sulfureum. True dermatophytes such as Nannizzia fulva appeared in $20{\sim}30%$ of the male samples.

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.389-393
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• 2003

The essential oils from Cedrus atlantica, Styrax tonkinensis, Juniperus communis, Lavandula angustifolia, Melaleuca alternifolia, Pelargonium graveolens, Pogestemon patchouli and Rosmarinus officinalis were analyzed by GC-MS. Antifungal activities of the oils were investigated by disk diffusion assay and the broth dilution method against Aspergillus niger and A. flavus. The effects of geraniol and the essential oil fraction from P. graveolens on the antifungal activity of amphotericin Band ketoconazole were examined using a checkerboard microtiter assay against both Aspergillus fungi. Most of the tested essential oils, with the exception of C. atlantica, J. communis, and P. patchouli, significantly inhibited growth of A. niger and to a lesser extent that of A. fIavus, with MICs (minimal inhibitory concentrations) in the range 0.78-12.5 mg/mL. The essential oil fraction of P. graveolens and its main components, geraniol and citronellol, exhibited additive effects with amphotericin B and with ketoconazole against both Aspergillus species, resulting in fractional inhibitory concentration (FIC) indices ranging from 0.52 to 1.00.

• Korean Journal of Microbiology
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• v.18 no.2
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• pp.51-58
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• 1980

Mutational experiments were performed to improved to improve the protease productivity of Aspergillus flavus KU 153, which is selected among the wild strains. A UV-induced mutant strain having high protease productivity was obtained by the use of the clear zone method as a simple criterion for a primary screening test. Neutral and alkaline protease activities of hte mutant strain were higher than 1.8 times, comopared with those of the parental strain, respectively, while in the case of acid protease, it was 2.7 times. The mutant strain selected was more powerful in the production of cellulase and amylase, as well s protease in wheat bran, compared with those of the parental strain. protease production of the parental strain has reached maximum level at 3 days culture, while alkaline nad neutral protease production of the mutantstrain has reached at 2 days culture. On the other hand, the mutant strain formed the spore slowly, compared with the parental strain. Column chromatography of the neutral protease on DEAE-Sephadex A-50 showed that the mutant strain was not induced the formation of another neutral protease isozyme, but induced the variation in the function of regulatory gene.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.679-682
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• 2002

The alkaloids, piperlongumine, piperine, pipernonaline, and piperoctadecalidine, isolated from Piper longum L., were found to inhibit the biosynthesis of aflatoxin $B_1$ (AF$B_1$) in Aspergillus flavus WRRC 3-90-42-12. Piperlongumine was the most active among the compounds tested, with a 96% inhibition of AF$B_1$biosynthesis at 0.2% (w/v) supplement in a potato dextrose agar (PDA) medium. The three other piperidine alkaloids, pipeline, pipernonaline, and piperoctadecalidine, also inhibited the biosynthesis of AF$B_1$. Of these three alkaloids, piperoctadecalidine exhibited a potent inhibitory activity with a 100% inhibition of AF$B_1$ production at 0.7% (w/v) supplement in a PDA medium. Therefore, piperlongumine and piperoctadecalidine could be used as antiaflatoxigenic agents in agricultural industries. To determine the antiaflatoxigenic mode of action of piperlongumine, further studies are needed.

• 한국균학회소식:학술대회논문집
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• 2015.11a
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• pp.28-28
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• 2015

Asexual reproduction or conidiation in aspergilli is a primary mean to produce their progenies that is environmentally and genetically controlled tightly. Previously, intensive researches in the model fungus Aspergillus nidulans disclosed some genes playing important roles in asexual and sexual development. Among them, one gene encoding a putative helix-loop-helix (HLH) transcription factor, named ndrA, has been isolated and characterized as a downstream regulator of developmental master regulator NsdD. By using comparative genome search of A. niduans NdrA protein, its orthologues have been identified in A. fumigatus and A. flavus, respectively (AfudrnA and AfldrnA). Deletion of the ndrA genes in both Aspergillus species made them unable to produce the conidia yet abundant production of sclerotia in A. flavus. Complementation of ndrA deletion strains by intact ndrA ORFs has restored the conidiation as in the control strains. In A. fumigatus, ndrA deletion also resulted in loss of conidiation phenotype. Northern analyses showed that the ndrA genes in both Aspergillus species are highly expressed at the early stage of the conidiation. Interestingly, the ndrA genes were found to be necessary for the proper expression of brlA genes. Antifungal sensitivity test revealed that the ndrA genes might be responsible for the sensitivity or resistance to some antifungal agents. However, ndrA deletion did not greatly influence the growth in both strains. And the A. flavus ndrA gene did not affect the aflatoxin production. Taken together, ndrA genes in Aspergillus species could be an important positive regulator of conidiation under the regulation of the nsdD gene yet upstream of the brlA gene.

• Mycobiology
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• v.31 no.2
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• pp.81-85
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• 2003

Antifungal properties of methyl 2-benzimidazole carbamate(BMC) were investigated using 16 fungi. Cytotoxicity test of BMC revealed that the morphology of HeLa cells was considerably deformed even at the concentrations as low as 0.1 ppm. Minimum inhibitory concentration(MIC) values of BMC for 7 fungi among the 16 tested ones were lower than $1.95{\times}10^{-4}{\mu}g/ml$, while Aspergillus flavus showed an MIC value higher than 1.0 ${\mu}g/ml$. Tolerance induction against BMC was successful only for Paecilomyces farinosus LAR10, contrary to the expectation that tolerance would be induced for the fungi having high MIC values such as Aspergillus niger ATCC 9642 and A. flavus ATCC 9643. Spore germination of A. niger ATCC 9642 was suppressed by BMC. However the mycelial growth of the fungus once germinated was not retarded at all by BMC up to 8 MIC. Addition of lanosterol provided a remedy for the reduced germination rate of A. niger ATCC 9642 spores.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.6
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• pp.571-575
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• 1995

A total of 455 food samples representing 22 different food types were collected from several localities at Alexandria province in Egypt. Aflatoxin B1 and aflatoxin M1 were detected in 5 out of 455 (1.1%) of these food samples. From the same samples 206 fungal isolates were obtained. Thirty two of these isolates (15.5%) were found to be aflatoxin producers. Aspergillus flavus was the dominant isolate, while Aspergillus parasaticus was also isolated from a few other food samples. Among locally consumed foodstuffs. Peanut (7.5%) and Milk powder (6.6%) were found to be a suitable substrates for aflatoxin production. The hygienic and public health significance of the isolated aflatoxigenic strains were discussed.

• Journal of the Korean Chemical Society
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• v.48 no.2
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• pp.177-181
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• 2004

1,2,4-Triazoles, pyrazolones and 1,3,4-oxadiazoles have been synthesized from substituted hydrazide using various solid supports under microwave irradiation (MWI). The results obtained highlight the versatility of the solid supports. All synthesized compounds were screened for their antifungal activity against A. niger and A. flavus and were found to possess good activity.