• The Korean Journal of Mycology
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• v.48 no.3
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• pp.187-195
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• 2020

Two unreported fungal isolates, KNU-GW1901 and KNU-AP100C, were collected from soil sample in Gyeongsangbuk-do, Korea. Their cultural and morphological characteristics were examined after 4 weeks of incubation at 25℃ on potato dextrose agar (PDA), malt extract agar (MEA), and oatmeal agar (OA). The conidial shape of KNU-GW1901 was aseptate, hyaline, globose to ellipsoidal, oblong, and reniform to pyriform and 2.61-4.97×1.93-3.61 ㎛ in size, whereas no conidial structures were observed in KNU-AP100C. The internal transcribed spacer (ITS) regions, large subunit (LSU), and small subunit (SSU) sequences were used to determine the taxonomic positions of the strains using the maximum likelihood phylogenetic tree. The isolate KNU-GW1901 was closely clustered with Plenodomus sinensis MFLUCC 17-0767, and KNU-AP100C was closely matched with P. collinsoniae CBS 120227. Based on the findings of morphological, cultural, and phylogenetic analysis, the isolates KNU-GW1901 and KNU-AP100C were identical to the previously described P. sinensis and P. collinsoniae isolates, respectively, which are first reported in Korea.

• Mycobiology
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• v.47 no.4
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• pp.355-367
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• 2019

Arthonia dokdoensis sp. nov., a lichenicolous fungus from the subcosmopolitan Arthonia molendoi complex growing on crustose thalli of species of the genus Orientophila (subfamily Xanthorioideae, Teloschistaceae), as well as the lichen species Rufoplaca toktoana sp. nov. (subfamily Caloplacoideae, Teloschistaceae) similar to Rufoplaca kaernefeltiana, both from Dokdo Islands, Republic of Korea, are described, illustrated, and compared with closely related taxa. In the phylogenetic tree of the Arthoniaceae based on 12S mtSSU and RPB2 gene sequences, the phylogenetic position of the A. dokdoensis and the relationship with the A. molendoi group are illustrated, while the position of the newly described R. toktoana is confirmed by phylogenetic tree based on ITS nrDNA data.

• ALGAE
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• v.23 no.2
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• pp.119-133
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• 2008

We cultured a tubular marine green alga, originally identified as Capsosiphon groenlandicus (J. Agardh) K.L. Vinogradova, from Amaknak Island, Alaska. The alga had an alternation of heteromorphic generations in which tubular monoecious fronds produced quadriflagellate zoospores and/or biflagellate isogametes. The gametes fused to produce cysts or Codiolum-like zygotes with long, tortuous stalks. Cysts and codiola produced 8-16 aplanospores, which germinated in situ to yield upright fronds. Fronds arising from both aplanospores and zoospores displayed a distinctive development in which non-septate colorless rhizoids from the base of the initially uniseriate, Ulothrix-like filament were transformed into septate uniseriate Ulothrix-like photosynthetic filaments. These transformed filaments then developed new basal non-septate rhizoids. This pattern of rhizoids becoming filaments, which then produced new rhizoids, was repeated to yield a tuft of up to 50 fronds. Periclinal and longitudinal divisions occurred in each filament, starting basally, until the mature tubular thallus was achieved. Pyrenoid ultrastructure revealed several short inward extensions of chloroplast lamellae, each of which was surrounded by pyrenoglobuli. Analysis of ribosomal SSU and ITS sequences placed this alga in the family Ulotrichaceae, order Ulotrichales, together with but as a distinct species from North Atlantic Capsosiphon groenlandicus. Analysis of a partial ITS sequence from authentic Capsosiphon fulvescens, the current name of the type of the genus Capsosiphon, indicated that neither our material nor C. groenlandicus belongs in that genus, and we propose a new genus, Pseudothrix, to accommodate both species. We propose P. borealis for the North Pacific entity formerly called C. groenlandicus and make the new combination P. groenlandica for the Atlantic species.

• Journal of Microbiology and Biotechnology
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• v.34 no.5
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• pp.1146-1153
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• 2024

The increasing economic losses associated with growth retardation caused by Enterocytozoon hepatopenaei (EHP), a microsporidian parasite infecting penaeid shrimp, require effective monitoring. The internal transcribed spacer (ITS)-1 region, the non-coding region of ribosomal clusters between 18S and 5.8S rRNA genes, is widely used in phylogenetic studies due to its high variability. In this study, the ITS-1 region sequence (~600-bp) of EHP was first identified, and primers for a polymerase chain reaction (PCR) assay targeting that sequence were designed. A newly developed nested-PCR method successfully detected the EHP in various shrimp (Penaeus vannamei and P. monodon) and related samples, including water and feces collected from Indonesia, Thailand, South Korea, India, and Malaysia. The primers did not cross-react with other hosts and pathogens, and this PCR assay is more sensitive than existing PCR detection methods targeting the small subunit ribosomal RNA (SSU rRNA) and spore wall protein (SWP) genes. Phylogenetic analysis based on the ITS-1 sequences indicated that the Indonesian strain was distinct (86.2% nucleotide sequence identity) from other strains collected from Thailand and South Korea, and also showed the internal diversity among Thailand (N = 7, divided into four branches) and South Korean (N = 5, divided into two branches) samples. The results revealed the ability of the ITS-1 region to determine the genetic diversity of EHP from different geographical origins.