• Fisheries and Aquatic Sciences
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• 제5권2호
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• pp.97-102
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• 2002

Pyricularia oryzae (P. oryzae), the cause of rice blast, is one of the most important fungal pathogens of rice. Seventy strains of marine fungi were isolated from marine algae, and it was measured antifungal activity against P. oryzae. Metabolites of marine fungus A-248 which isolated from marine algae showed strong antifungal activity against P. oryzae. The antifungal substance from the metabolites of marine fungus A-248 was extracted with ethylacetate, and then purified by preparative TLC and reverse-phase HPLC. The minimum inhibitory concentration (MIC) value was $0.18\mu g/mL$ for the antifungal activity of the substance purified from A-248 metabolites. The purified substance was similar to antifungal activity of rhizoxin, which is a commercial antifungal agent.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.922-931
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• 2009

Screening-scale studies were performed with 26 fungal cultures for their ability to transform the anti-inflammatory drug meloxicam. Among the different fungi screened, a filamentous fungus, Cunninghamella blakesleeana NCIM 687, transformed meloxicam to three metabolites in significant quantities. The transformation of meloxicam was confirmed by high-performance liquid chromatography (HPLC). Based on the liquid chromatography-tandem mass spectrometry (LC-MS/MS) data, two metabolites were predicted to be 5-hydroxymethyl meloxicam and 5-carboxy meloxicam, the major mammalian metabolites reported previously. A new metabolite was produced, which is not detected in mammalian systems. Glucose medium, pH of 6.0, temperature of $27^{\circ}C$, 5-day incubation period, dimethylformamide as solvent, and glucose concentration of 2.0% were found to be suitable for maximum transformation of meloxicam when studied separately. It is concluded that C. blakesleeana can be employed for biotransformation of drugs for production of novel metabolites.

• Mycobiology
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• 제48권3호
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• pp.240-244
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• 2020

Alternaria alternata JS-1623 is an endophytic fungus isolated from a stem tissue of Korean fir, Abies koreana. Ethyl acetate extracts of culture filtrates exhibited anti-inflammatory activity in LPS induced microglia BV-2 cell without cytotoxicity. Here we report a 33.67 Mb sized genome assembly of JS-1623 comprised of 13 scaffolds with N50 of 4.96 Mb, and 92.41% of BUSCO completeness. GC contents were 50.97%. Of the 11,197 genes annotated, gene families related to the biosynthesis of secondary metabolites or transcription factors were identified.

• Mycobiology
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• 제46권4호
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• pp.370-381
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• 2018

Bioactive natural compounds, isolated from fungal endophytes, play a promising role in the search for novel drugs. They are an inspiring source for researchers due to their enormous structural diversity and complexity. During the present study fungal endophytes were isolated from a well-known medicinal shrub, Berberis aristata DC. and were explored for their antagonistic and antioxidant potential. B. aristata, an important medicinal shrub with remarkable pharmacological properties, is native to Northern Himalayan region. A total of 131 endophytic fungal isolates belonging to eighteen species and nine genera were obtained from three hundred and thirty surface sterilized segments of different tissues of B. aristata. The isolated fungi were classified on the basis of morphological and molecular analysis. Diversity and species richness was found to be higher in leaf tissues as compared to root and stem. Antibacterial activity demonstrated that the crude ethyl acetate extract of 80% isolates exhibited significant results against one or more bacterial pathogens. Ethyl acetate extract of Alternaria macrospora was found to have potential antibacterial activity. Significant antioxidant activity was also found in crude ethyl acetate extracts of Alternaria alternata and Aspergillus flavus. Similarly, antagonistic activity of the fungal endophytes revealed that all antagonists possessed inhibition potential against more than one fungal pathogen. This study is an important step towards tapping endophytic fungal diversity for bioactive metabolites which could be a step forward towards development of novel therapeutic agents.

• Journal of Microbiology
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• 제43권6호
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• pp.475-486
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• 2005

Fungal secondary metabolites constitute a wide variety of compounds which either playa vital role in agricultural, pharmaceutical and industrial contexts, or have devastating effects on agriculture, animal and human affairs by virtue of their toxigenicity. Owing to their beneficial and deleterious characteristics, these complex compounds and the genes responsible for their synthesis have been the subjects of extensive investigation by microbiologists and pharmacologists. A majority of the fungal secondary metabolic genes are classified as type I polyketide synthases (PKS) which are often clustered with other secondary metabolism related genes. In this review we discuss on the significance of our recent discovery of chalcone synthase (CHS) genes belonging to the type III PKS superfamily in an industrially important fungus, Aspergillus oryzae. CHS genes are known to playa vital role in the biosynthesis of flavonoids in plants. A comparative genome analyses revealed the unique character of A. oryzae with four CHS-like genes (csyA, csyB, csyC and csyD) amongst other Aspergilli (Aspergillus nidulans and Aspergillus fumigatus) which contained none of the CHS-like genes. Some other fungi such as Neurospora crassa, Fusarium graminearum, Magnaporthe grisea, Podospora anserina and Phanerochaete chrysosporium also contained putative type III PKSs, with a phylogenic distinction from bacteria and plants. The enzymatically active nature of these newly discovered homologues is expected owing to the conservation in the catalytic residues across the different species of plants and fungi, and also by the fact that a majority of these genes (csyA, csyB and csyD) were expressed in A. oryzae. While this finding brings filamentous fungi closer to plants and bacteria which until recently were the only ones considered to possess the type III PKSs, the presence of putative genes encoding other principal enzymes involved in the phenylpropanoid and flavonoid biosynthesis (viz., phenylalanine ammonia-lyase, cinnamic acid hydroxylase and p-coumarate CoA ligase) in the A. oryzae genome undoubtedly prove the extent of its metabolic diversity. Since many of these genes have not been identified earlier, knowledge on their corresponding products or activities remain undeciphered. In future, it is anticipated that these enzymes may be reasonable targets for metabolic engineering in fungi to produce agriculturally and nutritionally important metabolites.

• Mycobiology
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• 제47권4호
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• pp.506-511
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• 2019

We investigated the antifungal activities of an endophytic fungus identified as Acaromyces ingoldii, found on a loblolly (Pinus taeda L.) pine bolt in Louisiana during routine laboratory microbial isolations. The specific objectives were to determine the inhibitory properties of A. ingoldii secondary metabolites (crude extract) on the mycelial growth of a brown-rot fungus Gloeophyllum trabeum and a white-rot fungus Trametes versicolor, and to determine the effective concentration of A. ingoldii crude preparation against the two decay fungi in vitro. Results show the crude preparation of A. ingoldii from liquid culture possesses significant mycelial growth inhibitory properties that are concentration dependent against the brownrot and white-rot fungi evaluated. An increase in the concentration of A. ingoldii secondary metabolites significantly decreased the mycelial growth of both wood decay fungi. G. trabeum was more sensitive to the inhibitory effect of the secondary metabolites than T. versicolor. Identification of specific A. ingoldii secondary metabolites, and analysis of their efficacy/specificity warrants further study. Findings from this work may provide the first indication of useful roles for Acaromyces species in a forest environment, and perhaps a future potential in the development of biocontrol-based wood preservation systems.

• Mycobiology
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• 제37권3호
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• pp.161-170
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• 2009

Cryptococcus neoformans is a basidiomycete human fungal pathogen that causes meningoencephalitis in both immunocompromised and immunocompetent individuals. The ability to sense and respond to diverse extracellular signals is essential for the pathogen to infect and cause disease in the host. Four major stress-activated signaling (SAS) pathways have been characterized in C. neoformans, including the HOG (high osmolarity glycerol response), PKC/Mpk1 MAPK (mitogen-activated protein kinase), calcium-dependent calcineurin, and RAS signaling pathways. The HOG pathway in C. neoformans not only controls responses to diverse environmental stresses, including osmotic shock, UV irradiation, oxidative stress, heavy metal stress, antifungal drugs, toxic metabolites, and high temperature, but also regulates ergosterol biosynthesis. The PKC(protein kinase C)/Mpk1 pathway in C. neoformans is involved in a variety of stress responses, including osmotic, oxidative, and nitrosative stresses and breaches of cell wall integrity. The $Ca^{2+}$/calmodulin- and Ras-signaling pathways also play critical roles in adaptation to certain environmental stresses, such as high temperature and sexual differentiation. Perturbation of the SAS pathways not only impairs the ability of C. neoformans to resist a variety of environmental stresses during host infection, but also affects production of virulence factors, such as capsule and melanin. A drug(s) capable of targeting signaling components of the SAS pathway will be effective for treatment of cryptococcosis.

• 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.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.258-258
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• 2005

• Toxicological Research
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• 제1권1호
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• pp.1-15
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• 1985

The trichothecenes are a chemically related sesquiterpenoid fungal metabolites of Fusarium, Trichoderma, Stachybotrys and others, and at moment more than 70 kinds of derivatives are identified. Historically, they are identified as antifungal and phytotoxic compounds, but after the finding of T-2 toxin from Fusarium tricinctum, several trichothecenes are now considered to be natural toxicants in foodstuffs and feeds.