• KSBB Journal
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• v.13 no.5
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• pp.497-501
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• 1998

A fungus with high phosphate solubilizing activites was isolated from soil using potato dextrose agar-calcium phosphate medium and identified to Penicillium sp. PS-113, based on the morphological characteristics of conidiophore and conidia; flask shape of phialide, simple branching type of conidiophore, and columnar shape of conidial head, in malt extract agar and potato dextrose agar media. The optimum temperature ad initial pH to solubilize rock phosphate in potato dextrose broth-rock phosphate medium were 30$^{\circ}C$ and pH 8.0, respectively. In these conditions phosphate solubilizing activities of Penicillium sp. PS-113 against four types of insoluble phosphate like tricalcium-phosphate, aluminium phosphate, hydroxyapatite and rock phosphate were quantitatively determined. As results, this fungus highly produced free phosphates to the culture broth with the concentrations of 1,283 ppm against tricalcium-phosphate, 585 ppm against rock phosphate, 528 ppm against aluminium phosphate, and 242 ppm against hydroxyapatite, respectively.

• Korean Journal of Microbiology
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• v.22 no.2
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• pp.91-96
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• 1984

The changes in the activities of Cellulase and Xylanase of A. phoencis during the life cycle were surveyed by using synchronized culture technique. Avicelase activity of the fungus was reached at peak in the initial hyphal growth stage, but decreased gradually during the conidiophore formation, vesicle-phialide formation, and sporulation stages in decreasing order. CMCase, Salicinase, and Xylanase activities were raised very high in the initial hyphal growth stage, but decreased gradually in conidiophore formation and vesicle-phialide formation stages, and then increased, more or less, in the sporulation stage.

• Korean Journal of Environmental Agriculture
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• v.26 no.1
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• pp.36-41
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• 2007

Phosphate-solubilizing microorganisms were isolated from soil around Kyungnam and Kyungbook regions using potato dextrose agar-calcium phosphate medium. A fungus with the greatest phosphate-solubilizing activity was selected and identified to Aspergillus sp. PS-104, based on the morphological characteristics of conidiophore and conidia; unbranching type of conidiophore, terminally swelling of conidiophore and septate of mycelium, in malt extract agar and potato dextrose agar media. The optimum temperature and initial pH to solubilize rock phosphate in potato dextrose broth-rock phosphate medium were $30^{\circ}C$ and pH 7.0, respectively. In these optimum conditions, phosphate-solubilizing activities of Aspergillus sp. PS-104 against four twos of insoluble phosphate, tricalcium phosphate, aluminium phosphate, hydroxyapatite and rock phosphate, were quantitatively determined. As result, the maximum phosphate-solubilizing activity was obtained with tricalcium-phosphate (1,900 ppm) while minimum activity was obtained with hydroxyapatite (320 ppm). Futhermore, phosphate-solubilizing activity of Aspergillus sp. PS-104 was found higher when treated with nitrates as compared to the ammonium salts as a nitrogen sources.

• Korean Journal of Microbiology
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• v.6 no.4
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• pp.113-121
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• 1968

This study has been aimed to determine the ecological factors with relationship to the Jongkok production in view of fermentation technology by means of some strains, Asp. kawachii, which is now preserved by the author and the following factors are included during the study; inorganic salts, nitrogen, sugar, water contents and temperature. The results, are as follows: (a) Sugar among other above-mentioned factors is increasingly affecting the number of the short type of conidiophore on culture medium and the conidiophore is increased by direct ratio until glucose concentration of 50%, at which concentration is mostly effective for the short type of conidiophore, while other factors did not affect on it. (b) Until glucose concentration of 50% sugar component of culture medium is favorable for the spore formation of Asp. kawachii by direct ratio. And peptone or asparagine on nitrogen medium, calcium-phosphate among other inorganic salts, wheat bran and rice branare also favorable, but other factors rientioned earlier show no relationship with the spore formation. Sugar, however, also related with the spore color clearness of crimson and light brown, and spore color is mostly clear at the point of glucose concentration until 50%. And asparagine on nitrogen medium, calcium phosphate among other inorganic salts, rice bran did all affect on the color clearness, while other factors did not concern with color clearness. (c) Water, sugar and temperature have related with the acid formation which is promoted, by direct ratio at the point of water-saturated condition and glucose concentration of 50%, while temperature at $25^{\circ}C$favorably affected on the acid formation which is increased by inverse ratio at the temperature$25^{\circ}C$ to $45^{\circ}C$ And pH did not relate with the acid formation. (d) Cylindrical plate method devised by the author is mostly favorable for the preservation and isolation of culture, compared with the traditional slant medium method.

• 한국균학회소식:학술대회논문집
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• 2014.05a
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• pp.39-39
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• 2014

In a homothallic filamentous fungus Aspergillus nidulans, sexual and asexual developments are largely affected by the genetic and environmental factors. To regulate the complex subsets of genes involved in the developmental processes accurately, tight regulations of transcription factors are required. The forkhead type transcription factors are the class of regulators that function in a broad spectrum of cellular and developmental processes in many species from yeast to human. Here, we identified the fkhA and fkhB genes that encode a conserved forkhead transcription factors. The fkhA deletion resulted in the complete loss of fruiting body formation under all conditions favoring sexual development, suggesting that the fkhA gene is required for sexual development in A. nidulans. Overexpression of fkhA resulted in enhanced formation of fruiting bodies under induction condition not only in the normal condition but also in the condition of presence of 0.6 M KCl, which strongly inhibits sexual development. To know the function of the fkhB gene, we also generated fkhB knock-out strain in A. nidulans. Deletion of fkhB resulted in abnormal conidiophore formation under standard conditions and delayed sexual development process, suggesting that the fkhB gene plays an important role in conidiophore morphogenesis Taken together, these results suggest that the fkhA gene is necessary and sufficient for regulating sexual development and the fkhB gene is a transcription factor related in asexual developmental process in A. nidulans.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.453-456
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• 2000

Antifungal activities of domestic plants were examined to develope natural antimicrobial agents, able to protect citrus fruits from spoiling microorganism during their storage. A fungus was isolated from citrus fruits' storage and identified to Penicillium sp. CF-301, based on the morphological characteristics of conidiophore and conidia; flask shape of phialide, simple branching type of conidiophore, and columnar shape of conidial head, in malt extract agar and potato dextrose agar media. Chloroform extracts of Juniperus chinesis Linnaeus, J. chinesis var. horizontalis showed remarkable antifungal activities against Penicillium sp. CF-301.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.397-401
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• 1998

Asexual spores of Mycosphaerella nawae were profusely produced on PDA after a prolonged incubation at $25^{\circ}C$ for 90 days. When persimmon trees were artificially inoculated by the conidial suspension, typical symptoms of circular leaf spot of persimmon appeared on the leaves two month later. The imperfect stag of the fungus was identified as Ramularia sp. based on following morphological characteristics examined under a light microscope and a scanning electron microscope. Conidia were mostly ellipsoid, but occasionally cylindrical, elongated oval, taro, peanut or gourd shapes and measured as 12.2~32.6$\times$6.1~10.2 ${\mu}{\textrm}{m}$. erect, hyaline, colorless-light brown. Conidia were formed solitarily or in chains on a medium and infected leaves. Conidiophore was erect, hyaline, colorless-light brown. and the size was 20.4~102.0$\times$3.1~10.2 ${\mu}{\textrm}{m}$, respectively. In this paper, we firstly demonstratrated that asexual spores of M. nawae induced persimmon circular leaf spot in nature as well as sexual spores of the fungus. Therefore, it is hypothesized that the imperfect stage of the fungus plays an important role in nature for epidemics as secondary inoculum.

• The Korean Journal of Mycology
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• v.20 no.4
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• pp.281-284
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• 1992

Two interesting new hyphomycetes collected on rachis of an unidentified palm (Palmao) from Malayasia are described and their taxonomy is discussed in this paper. One of them is unique in producing basauxic conidiophores from conidiophore mother cells that are sessile, simple, cylindrical or cupulate, and solitary, gangliar, acrogenous, dry phragmoconidia. It is classified in a new genus Basauxia, as a new species, B. pulchra. The other hyphomycete is also unique in producing characteristic solitary, eight-celled, eight-armed gangliar conidia on simple conidiophores. A new genus, Ashtaangam is proposed for it in which it is placed as a new species, A. sundaram.

• Korean Journal of Microbiology
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• v.26 no.1
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• pp.27-31
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• 1988

Biosynthesis and processing of cytoplasmic mRNA from heterogenous nuclear RNA (hn-RNA) in Aspergillus phoenicis were studied by $^{3}H$-uridine labeling and synchronous culture techniques during their life cycle. Incorporations of $^{3}H$-uridine into hn-RNA and mRNA were most rapid in vesicle-phialide fromation stage and diminished in hyphal growth stage. The processing of cytoplasmic mRNA from hn-RNA was proceeded more rapidly in hyphal growth and conidiophore formation stages than in conidia and vesicle-phialide formation stages. The specific radioactivities of hn-RNA and mRNA were very high in vesicle-phialide formation stage.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.312-317
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• 2009

Genome analysis of a model filamentous fungus, Aspergillus nidulans, revealed that there are six putative forkhead genes. Among them, fkhF (AN8949.2) showed A. nidulans-specific. fkhF gene is located in chromosome VII and composed of 2,337 bp coding region for 778 amino acid. Since little is known about the involvement of the forkhead proteins in the developmental process of the filamentous fungi, including A. nidulans, we generated a deletion mutant of fkhF gene and analyzed. Deletion of fkhF resulted in less-dense conidiophore formation in a solid culture. However, the sexual developmental process or cleistothecia formation was normal. Furthermore, fkhF deletion mutant produced conidiophores and conidia under the submerged culture, suggesting that the fkhF gene is involved in repression of inappropriated induction and maturation of asexual developmental process but not in sexual development.