• Journal of Applied Biological Chemistry
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• 제50권4호
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• pp.221-226
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• 2007

The high molecular-weight mucilage extracted and purified from cactus fruit of Opuntia ficus-indica var. Saboten was degraded by the cell-free culture filtrate of a fungus isolated from soil. TLC analysis of the polymeric mucilage after incubation with the fungal culture filtrate confirmed its degradation. When the degradation products were tested for their qualitative reactions with ninhydrin and phenol-sulfuric acid, only phenol-sulfuric acid gave positive development, and ninhydrin did not show any observable color reaction. This coloring reaction suggested the presence of a carbohydrate without an amino group within the mucilage. Analyses by HPLC and liquid gel permeation chromatography on sephadex G-100 also provided additional information on degradation of the mucilage by the fungal culture filtrate. The sequences of ITS-5.8S rDNA from the fungal isolate that was cultivated for the preparation of mucilage-degrading enzyme showed 99% similarity to those of Pestalotiopsis aquatica.

• Mycobiology
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• 제42권4호
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• pp.317-321
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• 2014

Fruiting bodies similar to those of the ascomycete fungi Podostroma cornu-damae and Cordyceps militaris were collected from Mt. Seunghak in Busan, Korea on August 21, 2012. The fruiting bodies were cylindrical, with tapered ends and golden red in color. The fruiting bodies contained abundant conidiophores bearing single-celled conidia, but no perithecia or asci. Pure culture of the fungal isolates was obtained through single-spore isolation. Analyses of morphological characteristics, including conidia shape, and phylogenetic traits, using internal transcribed spacer sequences, showed that these isolates belonged to the species Simplicillium lanosoniveum. Although this fungal species is known to be mycoparasitic, the isolates obtained in this study were unable to infect fungi. However, silkworms (Bombyx mori) inoculated with the fungal isolates died during the larval or pupal stages, as has been shown for the strongly entomopathogenic fungus Beauveria bassiana. This study is the first report of the entomopathogenicity of S. lanosoniveum and indicates its potential for use in biological control of insects.

• The Plant Pathology Journal
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• 제34권5호
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• pp.356-366
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• 2018

The red flour beetle, Tribolium castaneum, is one of the most common and economically important pests of stored cereal products worldwide. Furthermore, these beetles can act as vectors for several fungal post-harvest diseases. In this study, we collected T. castaneum from 49 rice processing complexes (RPCs) nationwide during 2016-2017 and identified contaminating fungal species on the surface of the beetles. Five beetles from each region were placed on potato dextrose agar media or Fusarium selection media after wet processing with 100% relative humidity at $27^{\circ}C$ for one week. A total of 142 fungal isolates were thus collected. By sequence analysis of the internal transcribed spacer region, 23 fungal genera including one unidentified taxon were found to be associated with T. castaneum. The genus Aspergillus spp. (28.9%) was the most frequently present, followed by Cladosporium spp. (12.0%), Hyphopichia burtonii (9.2%), Penicillium spp. (8.5%), Mucor spp. (6.3%), Rhizopus spp. (5.6%), Cephaliophora spp. (3.5%), Alternaria alternata (2.8%) and Monascus sp. (2.8%). Less commonly identified were genera Fusarium, Nigrospora, Beauveria, Chaetomium, Coprinellus, Irpex, Lichtheimia, Trichoderma, Byssochlamys, Cochliobolus, Cunninghamella, Mortierella, Polyporales, Rhizomucor and Talaromyces. Among the isolates, two known mycotoxin-producing fungi, Aspergillus flavus and Fusarium spp. were also identified. This result is consistent with previous studies that surveyed fungal and mycotoxin contamination in rice from RPCs. Our study indicates that the storage pest, T. castaneum, would play an important role in spreading fungal contaminants and consequently increasing mycotoxin contamination in stored rice.

• 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.

• 한국산림과학회지
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• 제96권5호
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• pp.515-519
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• 2007

An imperfect fungus Fusiococcum species was isolated from Quercus dentata. A naturally infected Daimyo oak tree was collected and showed elongate wounds on the stem. The fungal cultures were initially white and cottony, and later turned dark gray. Numerous solitary pycnidia were developed on the medium surface, and typically spherical. Yellowish conidial masses were exuded from pycnidia on the culture plates. Conidial masses were swollen and measured as approximately 100 to $300{\mu}m$ in length. It appeared that conidia were usually held together in globose to oval drops. Conidia were hyaline, single-celled (nonseptate), ellipsoid to fusoid, and measured as approximately $8.0{\times}2.7{\mu}m$. Based on these cultural and morphological characteristics, the fungal isolate was identified as a species of Fusicoccum Corda. To preserve and examine fungal spores exuded from pycnidia on the medium surface, a vapor fixation procedure for scanning electron microscopy was employed in this study. The specimens were exposed to the vapor of 2% (v/v) glutaraldehyde and 2% (w/v) osmium tetroxide each for 2 h. With the vapor fixation we obtained excellent retention of conidial masses in this study. The simple and versatile procedure for demonstrating fungal spores and their exudation from fruiting bodies would facilitate characterization of diverse pathological and environmental isolates as they are in native environments.

• Mycobiology
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• 제48권1호
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• pp.29-36
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• 2020

During an investigation of fungi of the order Mucorales from freshwater and sediment samples in Korea, we isolated six strains, NNIBRFG6649, NNIBRFG6255, NNIBRFG1498, CNUFC-YJ13, CNUFC-YR7, and NNIBRFG2739. The morphology and phylogeny of these strains were analyzed. Based on the morphological characteristics and molecular data from internal transcribed spacer (ITS) region, the isolates NNIBRFG6649 and NNIBRFG6255 were identified as Mucor abundans, and M. aligarensis, respectively. The isolates NNIBRFG1498 and CNUFC-YJ13 were identified as M. moelleri, whereas the isolates CNUFC-YR7 and NNIBRFG2739 were identified as M. heterogamus. To the best of our knowledge, M. abundans, M. aligarensis, M. moelleri, and M. heterogamus have not yet been reported in Korea.

• Journal of Microbiology and Biotechnology
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• 제20권8호
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• pp.1179-1184
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• 2010

We report the generation of the first monoclonal antibody that specifically binds to the polysaccharide chitosan. Mice were immunized with a mixture of chitosans, and hybridoma clones were screened for specific binders, resulting in the isolation of a single clone secreting a chitosan-specific IgM, mAbG7. In ELISAs, the antibody could bind to chitosans of varying composition, but demonstrated the highest affinity for chitosans with lower degrees of acetylation (DA) and very poor binding to chitin. We tested the ability of the antibody to bind to chitosan in situ, using preparations of fungal cell walls. Immunofluorescence microscopy confirmed that the antibody bound strongly to the cell walls of fungi with high levels of chitosan, whereas poor staining was observed in those species with cell walls of predominantly chitin or cellulose. The potential use of this antibody for the detection of fungal contamination and the protection of plants against fungal pathogens is discussed.

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1206-1211
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• 2013

The selective inhibition of PTP1B has been widely recognized as a potential drug target for the treatment of type 2 diabetes and obesity. In the course of screening for PTP1B inhibitory fungal metabolites, the organic extracts of several fungal species isolated from marine environments were found to exhibit significant inhibitory effects, and the bioassay-guided investigation of these extracts resulted in the isolation of fructigenine A (1), cyclopenol (2), echinulin (3), flavoglaucin (4), and viridicatol (5). The structures of these compounds were determined mainly by analysis of NMR and MS data. These compounds inhibited PTP1B activity with 50% inhibitory concentration values of 10.7, 30.0, 29.4, 13.4, and 64.0 ${\mu}M$, respectively. Furthermore, the kinetic analysis of PTP1B inhibition by compounds 1 and 5 suggested that compound 1 inhibited PTP1B activity in a noncompetitive manner, whereas compound 5 inhibited PTP1B activity in a competitive manner.

• Mycobiology
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• 제41권4호
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• pp.252-255
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• 2013

Fungal pathogens have caused severe damage to the commercial production of Pleurotus eryngii, the king oyster mushroom, by reducing production yield, causing deterioration of commercial value, and shortening shelf-life. Four strains of pathogenic fungi, including Trichoderma koningiopsis DC3, Phomopsis sp. MP4, Mucor circinelloides MP5, and Cladosporium bruhnei MP6, were isolated from the bottle culture of diseased P. eryngii. A species-specific primer set was designed for each fungus from the ITS1-5.8S rDNA-ITS2 sequences. PCR using the ITS primer set yielded a unique DNA band for each fungus without any cross-reaction, proving the validity of our method in detection of mushroom fungal pathogens.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1246-1253
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• 2008

Phyllosticta melochiae, an endophytic fungus isolated from the healthy leaves of Melochia corchorifolia, was screened for the production of an anticancer drug, taxol on modified liquid medium and potato dextrose broth medium in culture for the first time. The presence of taxol was confirmed by spectroscopic and chromatographic methods of analysis. The amount of taxol produced by this fungus was quantified by high performance liquid chromatography. The maximum amount of fungal taxol production was recorded as $274{\mu}g/L$. The production rate was increased to $5.5{\times}1,000$ fold than that found in the culture broth of earlier reported fungus, Taxomyces andreanae. The fungal taxol extracted also showed a strong cytotoxic activity in the in vitro culture of tested human cancer cells by apoptotic assay. The results designate that the fungal endophyte, P. melochiae is an excellent candidate for an alternate source of taxol supply and can serve as a potential species for genetic engineering to enhance the production of taxol to a higher level.