• Mycobiology
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• 제51권4호
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• pp.210-215
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• 2023

The aim of this study was to characterize a new fungal species, Acremonium conglutinatum, isolated from air samples collected in Wando, South Korea. Phylogenetic analysis based on the internal transcribed spacer and large subunit regions revealed its unique position within the genus Acremonium. The isolated strain displayed distinct morphological characteristics, including ellipsoid or bent-ellipsoid conidia formed in clusters on the phialides. These features differentiate the new species from closely related species within the genus. This study describes the morphological and molecular characteristics of A. conglutinatum and emphasizes its phylogenetic relationships with other Acremonium spp. The identification of this novel species contributes to our understanding of the diversity and ecological role of Acremonium.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 춘계학술대회 및 임시총회
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• pp.27-28
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• 2014

Beauveria bassiana (Cordycipitaceae, Hypocreales, Ascomycota) is an anamorphic fungus having a potential to be used as a biological control agent because it parasitizes a wide range of arthropod hosts including termites, aphids, beetles and many other insects. A number of bioactive secondary metabolites (SMs) have been isolated from B. bassiana and functionally verified. Among them, beauvericin and bassianolide are cyclic depsipeptides with antibiotic and insecticidal effects belonging to the enniatin family. Non-ribosomal peptide synthetases (NRPSs) play a crucial role in the synthesis of these secondary metabolites. NRPSs are modularly organized multienzyme complexes in which each module is responsible for the elongation of proteinogenic and non-protein amino acids, as well as carboxyl and hydroxyacids. A minimum of three domains are necessary for one NRPS elongation module: an adenylation (A) domain for substrate recognition and activation; a tholation (T) domain that tethers the growing peptide chain and the incoming aminoacyl unit; and a condensation (C) domain to catalyze peptide bond formation. Some of the optional domains include epimerization (E), heterocyclization (Cy) and oxidation (Ox) domains, which may modify the enzyme-bound precursors or intermediates. In the present study, we analyzed genomes of B. bassiana and its allied species in Hypocreales to verify the distribution of NRPS-encoding genes involving biosynthesis of beauvericin and bassianolide, and to unveil the evolutionary processes of the gene clusters. Initially, we retrieved completely or partially assembled genomic sequences of fungal species belonging to Hypocreales from public databases. SM biosynthesizing genes were predicted from the selected genomes using antiSMASH program. Adenylation (A) domains were extracted from the predicted NRPS, NRPS-like and NRPS-PKS hybrid genes, and used them to construct a phylogenetic tree. Based on the preliminary results of SM biosynthetic gene prediction in B. bassiana, we analyzed the conserved gene orders of beauvericin and bassianolide biosynthetic gene clusters among the hypocrealean fungi. Reciprocal best blast hit (RBH) approach was performed to identify the regions orthologous to the biosynthetic gene cluster in the selected fungal genomes. A clear recombination pattern was recognized in the inferred A-domain tree in which A-domains in the 1st and 2nd modules of beauvericin and bassianolide synthetases were grouped in CYCLO and EAS clades, respectively, suggesting that two modules of each synthetase have evolved independently. In addition, inferred topologies were congruent with the species phylogeny of Cordycipitaceae, indicating that the gene fusion event have occurred before the species divergence. Beauvericin and bassianolide synthetases turned out to possess identical domain organization as C-A-T-C-A-NM-T-T-C. We also predicted precursors of beauvericin and bassianolide synthetases based on the extracted signature residues in A-domain core motifs. The result showed that the A-domains in the 1st module of both synthetases select D-2-hydroxyisovalerate (D-Hiv), while A-domains in the 2nd modules specifically activate L-phenylalanine (Phe) in beauvericin synthetase and leucine (Leu) in bassianolide synthetase. antiSMASH ver. 2.0 predicted 15 genes in the beauvericin biosynthetic gene cluster of the B. bassiana genome dispersed across a total length of approximately 50kb. The beauvericin biosynthetic gene cluster contains beauvericin synthetase as well as kivr gene encoding NADPH-dependent ketoisovalerate reductase which is necessary to convert 2-ketoisovalarate to D-Hiv and a gene encoding a putative Gal4-like transcriptional regulator. Our syntenic comparison showed that species in Cordycipitaceae have almost conserved beauvericin biosynthetic gene cluster although the gene order and direction were sometimes variable. It is intriguing that there is no region orthologous to beauvericin synthetase gene in Cordyceps militaris genome. It is likely that beauvericin synthetase was present in common ancestor of Cordycipitaceae but selective gene loss has occurred in several species including C. militaris. Putative bassianolide biosynthetic gene cluster consisted of 16 genes including bassianolide synthetase, cytochrome P450 monooxygenase, and putative Gal4-like transcriptional regulator genes. Our synteny analysis found that only B. bassiana possessed a bassianolide synthetase gene among the studied fungi. This result is consistent with the groupings in A-domain tree in which bassianolide synthetase gene found in B. bassiana was not grouped with NRPS genes predicted in other species. We hypothesized that bassianolide biosynthesizing cluster genes in B. bassiana are possibly acquired by horizontal gene transfer (HGT) from distantly related fungi. The present study showed that B. bassiana is the only species capable of producing both beauvericin and bassianolide. This property led to B. bassiana infect multiple hosts and to be a potential biological control agent against agricultural pests.

• 생명과학회지
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• 제22권7호
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• pp.970-980
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• 2012

90종의 내생진균(endophytic fungi)은 염습지에 자생하고 있는 염생식물(halophyte)의 뿌리에서 분리하였다. 자생식물 샘플은 해홍나물, 갯질경, 칠면초, 갯잔디, 갈대가 염습지로부터 분리하였다. 그리고 분리된 내생진균들은 ITS1, 5.8S와 ITS2를 포함하는 ITS-rDNA 영역에 의해 분석하였다. 다양한 내생진균은 Capnodiales (4.44%), Cystofilobasidiales (1.11%), Dothideales (3.33%), Eurotiales (53.33%), Glomerellales (3.33%), Hypocreales (8.89%), Mucorales (1.11%), Pleosporales (15.56%), Sordariales (1.11%), Trichosphaeriales (1.11%), unidentified (6.67%) 등 10종류 목에 속하는 것이 확인되었다. 90종의 내생진균은 속(genus)단계에서 Acremonium 속, Alternaria 속, Aspergillus 속, Aureobasidium 속, Cephalosporium 속, Chaetomium 속, Cladosporium 속, Colletotrichum 속, Cryptococcus 속, Didymella 속, Dothideomycete 속, Emericellopsis 속, Epicoccum 속, Eupenicillium 속, Fusarium 속, Gibberella 속, Gongronella 속, Macrophoma 속, Microsphaeropsis 속, Nigrospora 속, Paecilomyce 속, Paraconiothyrium 속, Penicillium 속, Phaeomyces 속, Phoma 속, Pleosporales 속, Purpureocillium 속, 그리고 Talaromyces 속으로 모두 28속이 확인되었다. 그리고 동정된 모든 내생진균은 Eurotiales목의 Aspergillus속과 Penicillium속이 가장 많이 분포하고 있는 것이 확인되었다.

• 한국미생물·생명공학회지
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• 제40권4호
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• pp.287-295
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• 2012

부안갯벌에서 채집된 염생식물 칠면초와 해홍나물의 뿌리로부터 84종의 내생진균을 분리 및 동정하였다. 염생식물 샘플은 칠면초와 해홍나물이 부안갯벌로부터 분리되었다. 모든 내생진균류들은 ITS1, 5.8s와 ITS2를 포함하는 ITS영역의 서열에 의해 분석되었다. 내생진균류들은 Pleosporales (45%), Eurotiales (27%), Incertae sedis (11%), Dothideales (6%), Capnodiales (5%), Hypocreales (5%), 및 Agaricales (1%)에 해당하는 것을 확인하였다. 내생진균류는 자낭균문과 담자균문의 Alternaria속, Ascomycota속, Aspergillus속, Aureobasidium속, Cladosporium속, Eupenicillium속, Fusarium속, Gibberella속, Hocrea속, Lewia속, Macrophoma속, Penicillium속, Peyronellaea속, Phoma속, Pleospora속, Pleosporales속, Pseudeurotium속, Schizophyllum속, 그리고 Talaromyces속이 포함되는 것을 확인하였다. 그리고 alternaria (21%)와 Penicillium (13%)이 우점종인 것을 확인하였다. 본 연구에서는 칠면초와 해홍나물로부터 내생진균을 분리한 결과 Pleosporales 목과 Eurotiales 목의 Alternaria (21%)와 Penicillium (13%)이 가장 많이 분포하는 것으로 나타났다.

• 생명과학회지
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• 제23권1호
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• pp.95-101
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• 2013

본 연구에서는 독도에 자생하는 5종의 식물, 비짜루, 갯괴불주머니, 왕김의 털, 땅채송화, 갯강아지풀을 채집하였다. 독도의 자생식물 뿌리로부터 33 주의 내생진균을 분리하였다. 분리된 모든 내생진균류들은 ITS1, 5.8s와 ITS2를 포함하는 ITS영역의 서열에 의해 분석되었다. 그리고 내생진균류의 배양여과액을 이용하여 난장이벼 유묘에 처리하여 식물생장촉진활성을 확인하였다. 그 결과, 땅채송화로부터 분리된 D-So-1-1 내생진균이 가장 우수한 식물생장촉진활성을 나타내었다. 그리고 분리된 모든 내생진균는 자낭균문의 Eurotiales (86%), Capnodiales (3%), Hypocreales (4%), 및 Incertae sedis (7%)에 속하는 것을 확인하였다. 그리고 내생진균류를 속으로 분류하였을 때, Aspergillus (12%), Cladosporium (3%), Eurotium (3%), Fusarium (18%), Microsphaeropsis (6%), 및 Penicillium (58%)인 것으로 나타났다.

• 생명과학회지
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• 제22권10호
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• pp.1384-1391
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• 2012

본 연구에 사용된 해안식물은 울릉도의 해안지역으로부터 채집하였다. 그리고 식물은 큰비쑥, 해국, 갯질경이, 땅채송화, 갯강아지풀 등 5종류의 식물이 채집되었다. 울릉도에서 채집된 해안식물의 뿌리로부터 36주의 내생진균이 분리되었다. 모든 내생진균류는 ITS영역에 의해 분석 및 동정되었다. 그리고 계통분석 결과, 분리된 내생진균류는 모두 자낭균문에 속하고 4종류의 목(Capnodiales, Eurotiales, Hypocreales and Pleosporales)으로 분류되었으며, 이 중 Eurotiales 목이 가장 분포 비율이 높은 것으로 확인되었다. 그리고 내생진균류를 속으로 분류하였을 때, 9종류의 속(Alternaria, Aspergillus, Cladosporium, Exserohilum, Fusarium, Neosartorya, Penicillium, Phoma and Pyrenochaeta)으로 분류되었으며, Penicillium 속과 Aspergillus 속이 가장 우점종으로 확인되었다. 그리고 Shannon's diversity index (H')는 0.684에서 1.609의 분포로 나타났으며, 땅채송화에서 분리된 내생진균류의 다양성이 다른 식물에 비하여 높은 것으로 확인되었다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 춘계학술대회 및 임시총회
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• pp.20-20
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• 2015

Endophytic fungi are microorganisms inhabiting living plant tissues without causing apparent harm to the host. They are drawing increasing attention due to their ability to produce various bioactive compounds as well as their effects on host growth and resistance to biotic and abiotic stresses. As a first step to assess biodiversity of plant associated fungi in Korea and the following evaluation on diverse biological activities, we are collecting endophytic fungi from plant in wild followed by systematic long-term storage in liquid nitrogen. Molecular identification using ITS sequences was also incorporated for pure culture by hyphal tip isolation. As of April 2015, about 1,400 fungal strains had been isolated from about 170 plant taxa. Fungal isolates belonging to Pleosporales, Diaporthales, Glomerellales, Hypocreales, and Xylariales were the most abundant. These collections are being used for several complementary researches, including screening of isolates with novel bioactive compounds or conferring drought stress resistance, phylogenetic and genomic study. Genome sequencing was performed for 3 isolates, one Xylaria sp. strain JS573 producing griseofulvin, an antifungal compound, and two Fusarium spp. strains JS626 and JS1030, which are assumed to be new species found in Korea. More detailed analysis on these genomes will be presented. These collections and genome informations will serve as invaluable resources for identifying novel bioactive materials in addition to expand our knowledge on fungal biodiversity.

• Mycobiology
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• 제48권1호
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• pp.20-28
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• 2020

Soil degradation can have an impact on the soil microbiota, but its specific effects on soil fungal communities are poorly understood. In this work, we studied the impact of soil degradation on the richness and diversity of communities of soil fungi, including three different degrees of degradation in Germany and Panama. Soil fungi were isolated monthly using the soil-sprinkling method for 8 months in Germany and 3 months in Panama, and characterized by morphological and molecular data. Soil physico-chemical properties were measured and correlated with the observed values of fungal diversity. We isolated a total of 71 fungal species, 47 from Germany, and 32 from Panama. Soil properties were not associated with fungal richness, diversity, or composition in soils, with the exception of soil compaction in Germany. The geographic location was a strong determinant of the soil fungal species composition although in both countries there was dominance by members of the orders Eurotiales and Hypocreales. In conclusion, the results of this work do not show any evident influence of soil degradation on communities of soil fungi in Germany or Panama.

• Mycobiology
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• 제42권2호
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• pp.93-99
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• 2014

The earliest pre-Linnaean fungal genera are briefly discussed here with special emphasis on the nomenclatural connection with the genus Cordyceps Fr. Since its valid publication under the basidiomycetous genus Clavaria Vaill. ex L. (Clavaria militaris L. Sp. Pl. 2:1182, 1753), the genus Cordyceps has undergone nomenclatural changes in the post-Linnaean era, but has stood firmly for approximately 200 years. Synonyms of Cordyceps were collected from different literature sources and analyzed based on the species they represent. True synonyms of Cordyceps Fr. were defined as genera that represented species of Cordyceps Fr. emend. G. H. Sung, J. M. Sung, Hywel-Jones & Spatafora. The most common synonyms of Cordyceps observed were Clavaria and Sphaeria Hall, reported in the 18th and in the first half of the 19th century, respectively. Cordyceps, the oldest genus in the Cordyceps s. s. clade of Cordycipitaceae, is the most preferred name under the "One Fungus = One Name" principle on priority bases.

• 한국균학회지
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• 제48권3호
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• pp.251-271
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• 2020

Diversity and community composition of bulb-associated fungi of Fritillaria Cirrhosae Bulbus source plants, which are used in traditional chinese medicine, in the eastern Himalaya-Hengduan Mountains, southwestern China, were estimated based on the internal transcribed spacer rDNA sequence analysis, using host plant species, geographic area, and plant phenology as variables. A total of 1,486 fungal sequences assigned to 251 operational taxonomical units (OTUs) were obtained from the bulbs. Fungal OTUs comprised 96.41% Ascomycotina, 3.52% Basidiomycotina, and 0.07% Zygomycotina. Sordariomycetes, Hypocreales, and Nectriaceae were the most frequent fungal lineages at each taxonomic rank. Fusarium, Ilyonectria, Tetracladium, Leptodontidium, and Tomentella were the top OTU-rich genera. Fusarium sp. 03, Ilyonectria rufa, Fusarium sp. 08, Ilyonectria sp. 03, and Leptodontidium orchidicola 03 represented the most frequent OTUs. Fusarium spp. were the most frequent general taxa. The distribution of fungal community exhibited preferences for host plant species, geographic area, and plant phenology. These findings are the foundation of our research on culturing and active metabolites of bulb-associated fungi of Fritillaria Cirrhosae Bulbus source plants.