Search

In this study, we aimed to screen potential antagonistic microorganisms against Erwinia amylovora , the causal agent of fire blight. From 127 unknown bacterial isolates tested, 2 bacterial strains (BCA3 and BCA19) were identified to show distinct antagonistic activity against E. amylovora in agar plate assay. Phylogenetic analysis of the 16s rRNA sequence identified both BCA3 and BCA19 as Pantoea ananatis. Among these BCA19 showed 13.9% stronger antagonistic activity than BCA3. Thus we further characterized antagonistic activity of BCA19. Culture filtrates (CF) of BCA19 significantly inhibited the swimming and swarming motility of E. amylovora. Ethyl acetate and n-butanol extracts of CF of BCA19 exhibited antibacterial activity in disk diffusion assay. Furthermore, gas chromatography–mass spectrometry analysis of ethyl acetate and n-butanol extracts of CF of BCA19 identified antibacterial compounds, including indole and hexahydropyrrolo[1,2-a]pyrazine-1,4-dione. Importantly, indole inhibited growth of E. amylovora with IC50 value of 0.109 ± 0.02 mg/mL (~930.4 μM). Whole genome sequence analysis of BCA 19 revealed gene clusters related with siderphore, andrimid, arylpolyene and carotenoid-type terpene production. This study indicates that BCA19 can be used as a potential biological control agent against Erwinia amylovora. [ABSTRACT FROM AUTHOR]

A fungal strain designated KNUF-22-014, belonging to the family Ophiocordycipitaceae, was isolated from a soil sample collected in Sobaeksan National Park, South Korea. Phylogenetic trees based on the combined sequences of internal transcribed spacer (ITS) regions and the large subunit of 28S rRNA (LSU) gene, as well as on five concatenated loci (LSU, ITS, translation elongation factor 1α, β-tubulin, and subunit 1 of RNA polymerase II), revealed that the isolate falls within the clade containing the genus Tolypocladium but occupies a distinct phylogenetic position. Its closest relative is T. tropicale. Morphologically, strain KNUF-22-014 can be distinguished from T. tropicale by the shape of its phialides (subcylindrical vs. lageniform), its conidiophore type (arborescent or unbranched vs. trichodermatoid), and its larger conidia size (2.1 ± 0.1 µm vs. 1.5 ± 0.1 µm). Phylogenetic analysis and morphological observations indicate that KNUF-22-014 represents a novel species in the genus Tolypocladium, for which the name Tolypocladium sobaeksanense sp. nov. is proposed. [ABSTRACT FROM AUTHOR]

The order Chaetothyriales encompasses black yeasts and related fungi known for their diverse morphologies, asexual reproduction, and habitat preferences. In this study, we isolated two fungal strains belonging to Chaetothyriales, designated KNUF-23-13A and KNUF-22-020, from a longhorn beetle (Cyrtoclytus capra) and soil sample, respectively, in Korea. Phylogenetic analyses based on the concatenated nucleotide sequences of the internal transcribed spacer regions and partial sequences of the large subunit (LSU) rRNA, β-tubulin (TUB2), and actin (ACT) genes revealed that the strains were grouped with strains of Trichomerium and Exophiala, respectively. For strain KNUF-23-13A, cultural and morphological differences were observed in the shape and size of mycelium between it and its phylogenetically closest species, Trichomerium lapideum CGMCC 3.17311T, supporting the novelty of this isolated species. In the case of strain KNUF-22-020, the cultural and morphological characteristics were similar to those previously reported for E. radicis P2854T. Based on morphological and phylogenetic analyses, we revealed KNUF-23-13A as a novel species, which we describe and name T. koreanum sp. nov., and KNUF-22-020 as Exophiala radicis, a previously unreported species in Korea. [ABSTRACT FROM AUTHOR]

The species within the family Cunninghamellaceae during an investigation of soil microfungi in Korea, in which three strains were isolated from Gangwon, Chungbuk, and Gyeongbuk provinces, designated as KNUF-22-121A, KNUF-22-126A, and KNUF-22-316, respectively. Because the morphological and molecular analyses of these three strains were identical, KNUF-22-316 underwent further detailed study. Phylogenetic analyses based on the concatenated nucleotide sequences of the internal transcribed spacer region and the large subunit 28S rRNA gene revealed that the strain belonged to the genus Absidia, but occupied a distinct phylogenetic position. The strain KNUF-22-316 was compared with closely related species Absidia radiata CGMCC 3.16257T and Absidia yunnanensis CGMCC 3.16259T, morphologically different with shorter sporangiophores, smaller sporangia and columellae, and the consistent presence of collars. Here, we provide a detailed description and images of this proposed new species, which we have named Absidia microsporangia sp. nov. [ABSTRACT FROM AUTHOR]

The fungal strain designated as KNUF-21-020, belonging to the genus Triangularia, was isolated from a soil sample collected in the Chungnam province, Korea. Phylogenetic analyses based on the concatenated nucleotide sequences of internal transcribed spacer regions and partial sequences of large subunit rRNA, beta-tubulin, and RNA polymerase II subunit genes revealed that the strain was grouped in a clade with Triangularia species. However, it occupied a distinct phylogenetic position. We also observed morphological differences between strain KNUF-21-020 and closely related species. Here, we provided detailed descriptions, illustrations, and discussions regarding the morphological and phylogenetic analyses of the closely related species to support the novelty of this isolated species. The phylogenetic analyses and morphological observations indicate that the strain KNUF-21-020 represents a novel species in the genus Triangularia (family: Podosporaceae). We have designated this species as Triangularia manubriata sp. nov. [ABSTRACT FROM AUTHOR]