• Mycobiology
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• 제37권3호
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• pp.171-182
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• 2009

Many aspergilli that belongs to ascomycetes have sexuality. In a homothallic or self-fertile fungus, a number of fruiting bodies or cleistothecia are formed in a thallus grown from a single haploid conidia or ascospores. Genome-sequencing project revealed that two mating genes (MAT) encoding the regulatory proteins that are necessary for controlling partner recognition in heterothallic fungi were conserved in most aspergilli. The MAT gene products in some self-fertile species were not required for recognition of mating partner at pheromone-signaling stage but required at later stages of sexual development. Various environmental factors such as nutritional status, culture conditions and several stresses, influence the decision or progression of sexual reproduction. A large number of genes are expected to be involved in sexual development of Emericella nidulans (anamorph: Aspergillus nidulans), a genetic and biological model organism in aspergilli. The sexual development process can be grouped into several development stages, including the decision of sexual reproductive cycle, mating process, growth of fruiting body, karyogamy followed by meiosis, and sporulation process. Complicated regulatory networks, such as signal transduction pathways and gene expression controls, may work in each stage and stage-to-stage linkages. In this review, the components joining in the regulatory pathways of sexual development, although they constitute only a small part of the whole regulatory networks, are briefly mentioned. Some of them control sexual development positively and some do negatively. Regarding the difficulties for studying sexual differentiation compare to asexual one, recent progresses in molecular genetics of E. nidulans enlarge the boundaries of understanding sexual development in the non-fertile species as well as in fertile fungi.

• 미생물학회지
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• 제10권3호
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• pp.128-151
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• 1972

한국 토괴균의 계속적인 연구로서, 분리된 균류중 Aspergillus 8종과 microfungi 5종인 Alternaria alternata, Chrysosporium pannorum, Doratomyces microsporus, Trichoderma koningii, T. viride에 관하여 보고하였다. 이들 동정된 균류 중 아직까지 한국에서 미기록된 것으로는 Chrysosporium pannorum, Doratomyces microsporus, Trichoderma koningii, T. viride 등의 4종이었다. 또한 완전연대인 Emericella nidulans var. nidulans에 관하여 보고하였다.

• 미생물학회지
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• 제18권2호
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• pp.104-114
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• 1980

Fourteen species of the hyphomyceteous fungi isolated from Korean soils are described and illustrated. Among these, one species has teleomorphic state and is identified as Emericella nidulans var. nidulans, similar to Emericella spectabilis with the exception of size of the conidiophores as well as color and the arrangement of the hulle cells. Four species of hyphomyceteous fungi. Chrysosporium pannorum, Doratomyces microsporus, Trichoderma Roningii, T. viride, are reported here for the first time in Korea.

• Mycobiology
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• 제30권3호
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• pp.117-127
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• 2002

Cleistothecial development in Aspergillus nidulans(teleomorph, Emericella nidulans) was examined with the transmission electron microscopy. Cleistothecial initial was a small coiled lump of cells, ca. 6 ${\mu}m$ in diameter, which was consisted of a slightly swollen core with a short "tail" hypha. Initials were wrapped with a loose layer of hyphae. Core cells of cleistothecial initials were broad and multinucleated at first, then formed dikaryotic ascogenous cells, followed by post-meiotic tetra-nucleate or octa-nucleate protoasci and finally mature ascospores. Croziers were formed early during cleistothecium development. The peridial layer of mature cleistothecia was derived from the wrapping hyphae which originally invested the young cleistothecium. Completion of peridial layers development was associated with the depositing of a non-enzyme reactive material around peridial cells. $H\ddot{u}lle$ cell formation during the cleistothecial development appeared to be somewhat coordinated with the developmental stages of cleistothecium.

• Mycobiology
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• 제36권3호
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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.

• 대한임상검사과학회지
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• 제48권1호
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• pp.15-21
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• 2016

Aspergillus는 가장 흔하게 감염을 일으키는 기회 감염균이다. 검사실에서 Aspergillus의 동정은 대부분 형태학적으로 이루어진다. 최근에는 형태학적으로 동정이 안 되거나, 속 수준까지만 동정이 되는 까다로운 균들 동정하기 위하여 분자유전학적인 방법들이 제안되고 있다. 임상검체에서 분리한 475건의 Aspergillus는 Aspergillus fumigatus 257주(54.1%), A. niger 101주(21.3%), A. flavus 43주(9.1%), A. terreus 29주(6.1%), Aspergillus nidulans 2주(0.4%), 그리고 Aspergillus clavatus 1주(0.2%), 그리고 Aspergillus species는 42주(8.8%)이었다. 미동정 균주와 종 구분을 위한 11건의 염기서열분석에서는 Aspergillus fumigatus 5주, Aspergillus falvus 1주, Aspergillus terreus 1주, Aspergillus lentulus 1주 동정되었다. Aspergillus versicolor 2주, 그리고 1주는 Emericella parvathecia로 동정되었다. Aspergillus의 92.2%는 형태학적으로 동정이 가능하였고, 8.8%는 종 수준의 동정이 불가능하였다. 종 수준의 동정을 하기 위해서는 ITS와 D1D2를 이용한 염기서열분석이 유용한 것으로 사료된다.

• 한국균학회지
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• 제15권3호
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• pp.187-195
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• 1987

두가지 열처리법에 의한 균 분리방법을 사용하여, 보통균을 제외한 토양균의 분리와 그의 논토양중의 수직 및 계절별 분포를 파악하기 위하여 역곡동과 신원동의 논토양을 시료로 사용하였다. $42^{\circ}C$에서 2일간 배양후 $37^{\circ}C$로 배양하는 방법과 $70^{\circ}C$에서 15분간 열처리하는 방법을 사용하였다. $42^{\circ}C$ 배양법에서는 두 장소에서 분리된 토양균은 거의가 mesophile이었으며 thermotolerant fungi는 Asergillus fumigatus, thermophile로는 Sporotrichum thermophile과 Malbranchea pulchella var. sulfrea이었고, 이들 중 우점종은 Asergillus fumigatus이었다. 두 장소에서 9속, 14종이 분리동정되었으며 Sporotrichum thermophile, Talaromyces ucrainicus, Malbranchea pulchella var. sulfrea는 한국 미기록 종이다. $72^{\circ}C$ 열처리방법으로 분리한 경우 두 장소에서 10속, 20종이 분리동정되었으며, 분리된 균은 거의가 mesophile이었으며 thermotolerant fungi는 Asergillus fumigatus이었고, 우점종은 Talaromyces stipitatus이었다. 또한 Talaromyces helicus var. major, Emericella nidulans var. nidulans, Chaetomium subspirale, Neosartorya fishiri var. fischeri는 한국 미기록 종이다. 두가지 분리방법으로 분리된 토양균의 계절적 분포는 여름과 봄이 가을과 겨울보다 높았으며, 전체 균의 수와 우점종 균수, 그리고 나타나는 종의 빈도는 그 수직분포에 있어서 상층에서 가장 높았으나 하층으로 내려갈수록 감소하였다.

• Mycobiology
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• 제33권2호
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• pp.77-83
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• 2005

Seventy-three fungal species belonging to forty-three genera were isolated from 40 samples of Saccharrum officinarum (collected from Naage-Hamadi canal in Qena Governorate, Egypt). Aspergillus, Trichoderma, Mucor and Pythium were the most common genera on the two isolation media. The dominant species of Aspergillus were A. niger, A. flavus, A. ustus, A. terreus and A. wentii. Some species were dominant on 40 g/l sucrose such as Aspergillus niger, A. flavus, Emericella nidulans, Trichoderma viride, Torula herbarum and Mamaria echinoeotryoides, while the dominant species on 10 g/l glucose were Mucor circinelloides, Aspergillus niger, Torula herbarum and Trichoderma viride. Mycotoxins including aflatoxins $B_1,\;B_2,\;G_1\;and\;G_2$, zearalenone and diacetoxyscirpenol were detected in the examined samples of Saccharrum officinarum. The mycelial growth of A. flavus, A. niger, Fusarium moniliforme and Torula herbarum decreased with the increase in Dimethoate concentrations, although 25 ppm was less effective than the higher levels of the insecticide ($75{\sim}200\;ppm$). Dimethoate stimulated the activity of Go-Tin A. niger, F. moniliforme and T. harbarum, while the Go-T activity was inhibited in A. flavus with the Dimethoate treatments.

• Mycobiology
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• 제43권2호
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• pp.137-149
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• 2015

In the search for novel potent fungi-derived bioactive compounds for bioinsecticide applications, crude ethyl acetate culture filtrate extracts from 110 mangrove fungal endophytes were screened for their toxicity. Toxicity tests of all extracts against brine shrimp (Artemia salina) larvae were performed. The extracts with the highest toxicity were further examined for insecticidal activity against Spodoptera litura larvae and acetylcholinesterase (AChE) inhibition activity. The results showed that the extracts of five isolates exhibited the highest toxicity to brine shrimp at 50% lethal concentration ($LC_{50}$) values of 7.45 to 10.24 ppm. These five fungal isolates that obtained from Rhizophora mucronata were identified based on sequence data analysis of the internal transcribed spacer region of rDNA as Aspergillus oryzae (strain BPPTCC 6036), Emericella nidulans (strains BPPTCC 6035 and BPPTCC 6038), A. tamarii (strain BPPTCC 6037), and A. versicolor (strain BPPTCC 6039). The mean percentage of S. litura larval mortality following topical application of the five extracts ranged from 16.7% to 43.3%. In the AChE inhibition assay, the inhibition rates of the five extracts ranged from 40.7% to 48.9%, while eserine (positive control) had an inhibition rate of 96.8%, at a concentration of 100 ppm. The extracts used were crude extracts, so their potential as sources of AChE inhibition compounds makes them likely candidates as neurotoxins. The high-performance liquid chromatography profiles of the five extracts differed, indicating variations in their chemical constituents. This study highlights the potential of culture filtrate ethyl acetate extracts of mangrove fungal endophytes as a source of new potential bioactive compounds for bioinsecticide applications.

• Journal of Microbiology and Biotechnology
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• 제16권1호
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• pp.145-148
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• 2006

A new functional lipolytic enzyme (AT4) has recently been found from Agrobacterium tumefaciens C58 Cereon using a genome-wide approach. The enzyme has some sequence similarity to E. coli acetyl hydrolase, Emericella nidulans lipase, Moraxella sp. lipase, Acinetobacter lwoffii esterase, and Streptomyces hygroscopicus acetyl hydrolase. However, the sequence similarities are very low (less than $25\%$), suggesting that it is a new lipase/esterase enzyme. ill the present study, intact cell of the A. tumefaciens strain was shown to have lipolytic activity on a tributyrin-LB plate. The AT4 gene was then expressed at a high level in E. coli BL21 (DE3) cells and the enzyme was purified simply by Ni-NTA column chromatography. The purified enzyme showed hydrolytic activity toward p-nitrophenyl caproate, but not toward olive oil, suggesting that the AT4 enzyme was a typical esterase rather than lipase. AT4 esterase had a maximum hydrolytic activity at $45^{\circ}C$ and pH 8.0, when p-nitrophenyl caproate was used as a substrate. It was relatively stable up to $40^{\circ}C$ and at pH 5.0-9.0. Calcium ion and EDT A did not affect the activity and thermal stability of the enzyme. As for substrate specificity, AT4 enzyme could rapidly hydrolyze acetyl and butyl groups from p-nitrophenyl esters and 1-naphthyl esters. In addition, it also released acetyl residues from acetylated glucose and xylose substrates. Therefore, this new esterase enzyme might be used as a biocatalyst in acetylation and deacetylation reactions performed in the fine chemical industry.