• 한국균학회지
• /
• 제47권3호
• /
• pp.187-197
• /
• 2019

Ascomycota is the largest phylum of the Fungi, including approximately 6,600 genera. They are often isolated from soils, indoor air, and freshwater environments, but also from plants as pathogens or endophytes. In this study, four species of Ascomycota (two of Cladosporium and one of each Daldinia and Nigrospora) were collected from the leaves of four woody plants (Camellia japonica, Ginkgo biloba, Quercus sp., Vitis vinifera). Their cultural characteristics were investigated on five different media (PDA, V8A, CMA, MEA, CZA) at 3 days after incubation at $25^{\circ}C$ in darkness. BLASTn search and phylogenetic analysis were performed using the internal transcribed spacer (ITS) rDNA sequences, in addition to tef1 gene sequences for Cladosporium species. Based on the cultural, morphological, and phylogenetic data, the isolates were identified as Cladosporium anthropophilum, Cladosporium pseudocladosporioides, Daldinia eschscholtzii, and Nigrospora chinensis. Previously, some members of Cladosporium and Nigrospora have been recorded as endophytes inhabiting the leaves and stems of various plants, whereas Daldinia eschscholtzii is a wood-inhabiting endophyte or wood-decaying fungus. To our knowledge, this is the first report of these four ascomycetes in Korea.

• 미생물학회지
• /
• 제52권1호
• /
• pp.32-39
• /
• 2016

독도에 자생하는 번행초의 뿌리로부터 순수 분리하여 형태적으로 상이한 17개의 내생균류를 선별하였다. 또한 분리된 균류들에 대하여 각각의 염농도와 pH 농도 구배에 따라 생장 시험을 확인하였다. 내생균류에 대해 각각 난장이벼의 유묘에 식물생장활성시험을 진행하였고, 그 결과 YH103 균주가 가장 높은 활성을 나타내었다. 계통분석은 Maximum likelihood 방법을 활용하여 결합된 ITS영역, beta-tubulin 및 calmodulin 유전자 염기서열을 분석하여 분리된 균주의 유연관계를 분석하였다. YH103 균주의 배양여과액을 HPLC와 GC/MS SIM을 이용하여 분석한 결과 식물호르몬인 지베렐린 $GA_4$, $GA_7$, $GA_8$ 및 $GA_{19}$가 확인되었다. 최종적으로 YH103 균주의 형태학적 관찰 및 결합된 유전자 염기서열의 분자적 분석을 통해 GA를 생산하는 새로운 Aspergillus tubingensis로 동정되었다.

• Journal of Photoscience
• /
• 제9권3호
• /
• pp.45-48
• /
• 2002

Microbial rhodopsins, photoactive 7-transmembrane helix proteins that use retinal as their chromophore, were observed initially in the Archaea and appeared to be restricted to extreme halophilic environments. Our understanding of the abundance and diversity of this family has been radically transformed by findings over the past three years. Genome sequencing of cultivated microbes as well as environmental genomics have unexpectedly revealed archaeal rhodopsin homologs in the other two domains of life as well, namely Bacteria and Eucarya. Organisms containing these homologs inhabit such diverse environments as salt flats, soil, freshwater, and surface and deep ocean waters, and they comprise a broad phylogenetic range of microbial life, including haloarchaea, proteobacteria, cyanobacteria, fungi, and algae. Analysis of the new microbial rhodopsins and their expression and structural and functional characterization reveal that they fulfill both ion transport and sensory functions in various organisms, and use a variety of signaling mechanisms. We have obtained the first crystallographic structure for a photosensory member of this family, the phototaxis receptor sensory rhodopsin II (SRII, also known as phoborhodopsin) that mediates blue-light avoidance by the haloarchaeon Natronobacterium pharaonis. The structure obtained from x-ray diffraction of 3D crystals prepared in a cubic lipid phase reveals key features responsible for its spectral tuning and its sensory function. The mechanism of SRII signaling fits a unified model for transport and signaling in this widespread family of phototransducers.

• Mycobiology
• /
• 제47권1호
• /
• pp.87-96
• /
• 2019

Fungi produce various secondary metabolites that have beneficial and harmful effects on other organisms. Those bioactive metabolites have been explored as potential medicinal and antimicrobial resources. However, the activities of the culture filtrate (CF) and metabolites of whiterot fungus (Schizophyllum commune) have been underexplored. In this study, we assayed the antimicrobial activities of CF obtained from white-rot fungus against various plant pathogens and evaluated its efficacy for controlling anthracnose and gray mold in pepper plants. The CF inhibited the mycelial growth of various fungal plant pathogens, but not of bacterial pathogens. Diluted concentrations of CF significantly suppressed the severity of anthracnose and gray mold in pepper fruits. Furthermore, the incidence of anthracnose in field conditions was reduced by treatment with a 12.5% dilution of CF. The active compound responsible for the antifungal and disease control activity was identified and verified as schizostatin. Our results indicate that the CF of white-rot fungus can be used as an eco-friendly natural product against fungal plant pathogens. Moreover, the compound, schizostatin could be used as a biochemical resource or precursor for development as a pesticide. To the best of our knowledge, this is the first report on the control of plant diseases using CF and active compound from white-rot fungus. We discussed the controversial antagonistic activity of schizostatin and believe that the CF of white-rot fungus or its active compound, schizostatin, could be used as a biochemical pesticide against fungal diseases such as anthracnose and gray mold in many vegetables.

• ALGAE
• /
• 제38권2호
• /
• pp.93-110
• /
• 2023

Progress in phylogenomic analysis has led to a considerable re-evaluation of former cyanobacterial system, with many new taxa being established at different nomenclatural levels. The family Geminocystaceae is among cyanobacterial taxa recently described on the basis of polyphasic approach. Within this family, there are six genera: Geminocystis, Cyanobacterium, Geminobacterium, Annamia, Picocyanobacterium, and Microcrocis. The genus Geminocystis previously encompassed two species: G. herdmanii and G. papuanica. Herein, a new species G. urbisnovae was proposed under the provision of the International Code of Nomenclature for algae, fungi, and plants (ICN). Polyphasic analysis was performed for five strains from the CALU culture collection (St. Petersburg State University, Russian Federation), and they were assigned to the genus Geminocystis in accordance with high 16S rRNA gene similarity to existing species, as well as because of proximity to these species on the phylogenetic trees reconstructed with RaxML and Bayes methods. Plausibility of their assignment to a separate species of the genus Geminocystis was substantiated with smaller cell size; stenohaline freshwater ecotype; capability to complementary chromatic adaptation of second type (CA2); distinct 16S rRNA gene clustering; sequences and folding of D1-D1' and B box domains of the 16S-23S internal transcribed spacer region. The second objective pursued by this communication was to provide a survey of the family Geminocystaceae. The overall assessment was that, despite attention of many researchers, this cyanobacterial family has been understudied and, especially in the case of the crucially important genus Cyanobacterium, taxonomically problematic.