• Korean Journal of Veterinary Service
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• v.46 no.3
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• pp.203-210
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• 2023

Breeding ducks are susceptible to fungal infections due to being bred in confined spaces for long periods. The objective of this study was to show the real state of the clinical fungal contamination of 22 duck breeding farms in Chungcheongbuk-do, South Korea. Out of the 430 carcasses obtained from the 22 duck breeding farms, 80 were diagnosed with invasive pulmonary aspergillosis (IPA). Aspergillus spp. were detected as the causative agents, including 26 cases of A. fumigatus, 35 cases of A. flavus, and 19 cases of A. terreus. The clinical lesions in the breeding ducks had circumscribed cream-and-yellow-colored plaques and/or white-to-greenish mycelium. Septate hyphae with parallel walls and dichotomous branching were observed in the histopathological lesions. AGMAg ELISA was performed to determine the overall positive rate of Aspergillus spp. in duck breeding farms. These results showed a positive rate of 58.97% for Aspergillus spp. Additionally, the positive rate increased with the age of the host.

• Mycobiology
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• v.31 no.2
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• pp.61-67
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• 2003

The mycobiota of the sandy soil of Egyptian beaches was investigated in thirty six sand samples collected from nine different localities in Egypt. The filamentous fungi were identified and assigned to thirty one genera and fifty one species. Greater populations as well as a wider spectrum range of fungal genera and species were obtained in sandy soil of Alexandria beach while Balteem beach was the poorest one. The total count of the genus or species was not depended upon cases of isolation. Most of the genera detected belonged to the Deuteromycotina with fewer proportions belonging to the Ascomycotina and Zygomycotina. The genera of highest incidence and their respective numbers of species were: Penicillium(35.72%, 6 species) and Aspergillus(30.28%, 16 species). The species which showed the highest incidence in all cases was P chrysogenum, followed by P citrinum, A. flavus, Chaetomium murorum and Trichoderma viride. A few number of other genera and species were also detected.

• Microbiology and Biotechnology Letters
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• v.19 no.2
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• pp.109-115
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• 1991

Twenty-five fungal strains producing an extracellular soybean milk clotting enzyme were isolated from 146 soil samples, and identified as 11 species belonging to six genera of Aspergillus oryzae (5 strains), Aspergillus flavus (2 strains), Aspergillus parasiticus (1 strain), Aspergillus tamarii (2 strains), Aspergillus niger (4 strains), Aspergillus fumigatus (2 strains), Mucor hiemalis (2 strains), Wallemia sebi (4 strains), Scopulariopsis condida (1 strain), Fusarium redolens(1 strain) and Verticillum lecanii (1 strain). Among them, Aspergillus oryzae 020 and Aspergillus tamarii 287 showed relatively high soybean milk clotting activity. The coagulabilities of the enzyme from representative strains of those species decreased as the pH of soybean milk increased from 6.0 to 7.0 The optimum temperature for soybean milk clotting enzymes of those strains were 65$^{\circ}C$.

• Mycobiology
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• v.36 no.3
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• pp.167-172
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• 2008

Beef luncheon meat is one of the most popular meals in several countries in the world including Egypt. Thirty one fungal species and 3 species varieties were recovered from 30 samples of beef luncheon meat collected from different supermarkets in Qena. Alternaria, Aspergillus, Emericella, Mucor, Mycosphaerella, Penicillium and Rhizopus were the most common genera on the two types of media. From the above genera, the most prevalent species were Alternaria alternate, Aspergillus flavus, A. fumigatus, A. niger, A. terreus, Emericella nidulans, Mucor racemosus, Mycosphaerella tassiana, Penicillium chrysogenum and Rhizopus stolonifer. Screening of fungi for their abilities to produce lipase enzyme showed that, ten isolates represented 32.26% of total isolates appeared high lipase production, while sixteen isolates (51.61%) were moderate and 5 isolates (16.13%) were low producers. Aspergillus niger, Fusarium oxysporum and Nectria haematococca produced the highest amount of lipase enzyme, so these fungi were used in further studies. The incorporation of five food preservatives (Disodium phosphate, sodium benzoate, citric acid, potassium sorbate and sodium citrate) individually in the culture medium of lipase production exhibited an inhibitive effect on the mycelial growth and enzyme production by Aspergillus niger, Fusarium oxysporum and Nectria haematococca.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.399-405
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• 2021

Until now, five species (Meghimatium bilineatum, M. fruhstorferi, Limax flavus, L. marginatus, Deroceras reticulatum) in three genera of families Philomycidae and Limacidae have been reported in Korea. Philomycidae is a family of air-breathing land snails. Meghimatium hongdoensis sp. nov. is described based on its middle size (60-80 mm in body length), its body coloration (dark-red yellow), no dorsal with streaks, its genitalia, and 16rDNA sequence analysis. Specimens of this new species were collected from Hongdo island, Sinan-gun, Jeollanam-do, Korea. This species is only known from the type locality at Hongdo to date. It could be found in high-humidity sites. Meghimatium uniforme (Laidlaw 1937) was the first one reported in Korea. It was also collected from Gageodo island, Sinan-gun, Jeollanam-do, Korea. In this study, morphological characteristics including their radula and genital structures of these two species were described. Preliminary results of mitochondrial 16S rDNA sequencing and phylogenetic analyses indicated that these species belonged to the Korean clade.

• The Korean Journal of Mycology
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• v.21 no.4
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• pp.316-322
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• 1993

Examination by scanning electron microscopy and potato-dextrose agar medium showed that the dry seeds of R. raetam were externally free of fungi. When planted in sandy loam soil, the seeds become colonized with eleven soilborne fungal species. The fungi were isolated on cellulose agar, pectin agar and lignin agar media. Aspergillus flavus, A. niger, Penicillium capsulatum and Fusarium oxysporum had broad occurrence and recovered on the three media. The production of hydrolytic enzymes by the isolated fungi depends on the substrate and species. P. capsulatum, P. spinulosum and A. niger had wide enzymatic amplitude and they were able to produce cellulolytic, pectolytic and lignolytic activities on corresponding substrates as well as on seed coat containing media. The lignolytic activities of the isolated species except Chaetomium bostrychods and Trichoderma viride were enhanced on applying the seed coat materials as C-source rather than using lignin. Soaking R. raetam seeds in culture filtrates of the most fungi grown on seed coat supplemented media induced pronounced and distinct stimulating effect on seed germination. The most effective filtrates were those of P. capsulatum, P. spinulosum and Sporotrichum pulverulentum.

• The Korean Journal of Mycology
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• v.27 no.4 s.91
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• pp.283-288
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• 1999

The effect of water activity ($a_w,\;0.9{\sim}0.995$) and temperature ($18{\sim}30^{\circ}$C) on in vitro growth and interactions between ochratoxin-producing Aspergillus ochraceus and six other fungi (Alternaria alternata, Aspergillus candidus, A. flavus, A. niger, Eurotium amstelodami, E. rubrum) isolated from maize grain were investigated. A. ochraceus and each six other species were paired and their interactions given a numerical score to obtain an index of dominance ($I_D$) for each species. Generally A. ochraceus was very competitive and dominant against other fungi. It was, however, dominanted by Alternaria alternata and A. niger at high $a_w\;(0.995\;a_w)$, and mutually antagonistic when paired with E. amstelodami and E. rubrum at low $a_w\;(0.9\;a_w)$. The growth rates of each species were also calculated under the same range of environmental conditions. They were markedly influenced by aw and temperature. At high temperature ($30^{\circ}C$), A. ochraceus grew most rapidly under slightly drier conditions ($0.95\;a_w$), while A. alternata, A. flavus and A. niger did at high water availability level ($0.995\;a_w$). At $18^{\circ}C\;and\;25^{\circ}C$, and high $a_w$ level ($0.995\;a_w$), A. alternata grew fastest, while A. candidus, E. amstelodami and E. rubrum grew very slowly. Using Biolog plates the effect of $a_w$ and temperature on utilization patterns of carbon sources in maize was evaluated. The niche overlap index (NOI) relative to A. ochraceus was determined and compared with that of each interacting species. Under high water available condition ($0.995\;a_w$). the NOI of A. ochraceus was often >0.9, indicative of the coexistence with other interacting species. However, against E. amstelodami and E. rubrum at $18^{\circ}C$, the species had NOI <0.8, indicative of occupation of different niches. At low $a_w\;(0.95\;a_w)$, NOI for A. ochraceus was <0.8 when paired with A. alternata and A. niger also suggested the occupation of different niches.

• Journal of Food Hygiene and Safety
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• v.31 no.1
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• pp.36-41
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• 2016

Ochratoxin A and aflatoxin may be detected from naturally fermented foods due to the contamination of the mycotoxin-producing molds or un-prudential use of the mycotoxin producing starter strains during the fermentation. This study was carried out to analyze the production of ochratoxin A and aflatoxin under the various environmental conditions. For the experiment, the effects of different temperature, culture media, and fermentation time on the production of ochratoxin A by Aspergillus usamii KFRI 999 and A. awamori KFRI 983 were analyzed. Additionally, the production of aflatoxin was assessed under the various temperature, initial pH, fermentation time and culture media during fermentation by A. flavus KACC 41403 and A. oryzae KACC 46471. The levels of ochratoxin A and aflatoxin were analyzed by HPLC. The result showed that the production of mycotoxin was greatly affected by the fermentation temperature. A. oryzae KACC 46471 did not produce aflatoxin. All of the mycotoxin producing strains showed the highest level of mycotoxin at $30^{\circ}C$. A. awamori KFRI 983 showed the lowest level of ochratoxin A in PDA media among the experimental medium. The results of the present study may be useful for the reduction of ochratoxin A and aflatoxin in various foods.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.926-931
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• 2011

A series of complexes of the type [$ML_2Cl_2$], where L=2-(o-anisylidene-2'-imino) amino benzimidazole (AIAB) and 2-(furfurylidene imino) amino benzimidazole (FIAB), M=Cu(II), Co(II), Ni(II) and Zn(II), have been synthesized and characterized on the basis of elemental analysis, thermal analysis, molar conductivity, magnetic moment, electronic, infrared, $^1H$-NMR spectral studies. The results are in consistent with bidentate chelation of ligand with azomethine nitrogen and ring nitrogen donors. All these Schiff bases and their complexes have also been screened for their antibacterial (Bacillus subtilis, Bacillus stearothermophilus, Escherichia coli and Salmonella typhi) and antifungal activities (Aspergillus niger and Aspergillus flavus).

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3530-3538
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• 2010

In this study 1-[4-(2-methoxy benzyl)-6-aryl-pyridazin-3(2H)-ylidene] hydrazines were used for the synthesis of new heterocyclic systems such as thiazolidine, phthalazine, pyrazolo, tetrazolo, hydrazide and new pyridazine derivatives to explore the effect of silver nanoparticles on their biological activity efficiency. Structures of the new heterocycles were characterized by the aid of several analytical techniques including; $^1H$-NMR, FTIR and mass spectra. Silver nanoparticles were synthesized by a simple methodology and the formation of silver nanoparticles was confirmed by transmission electron microscopy (TEM) and UV studies. Most of the new prepared heterocycles were evaluated in vitro as new antimicrobial agents. Combination effects of the silver nanoparticles on the antimicrobial activity of the new heterocycles were investigated using the disk diffusion method. Compound 10a exhibited the strongest enhancing effect of silver nanoparticles solution against Aspergillus flavus and Candida albicans.