• Mycobiology
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• v.43 no.4
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• pp.435-443
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• 2015

Sixty-one endophytic fungus strains with different colony morphologies were isolated from the leaves, stems and roots of Tephrosia purpurea with colonization rates of 66.95%, 37.50%, and 26.92%, respectively. Based on internal transcribed spacer sequence analysis, 61 isolates were classified into 16 genera belonging to 3 classes under the phylum Ascomycota. Of the 61 isolates, 6 (9.84%) exhibited antifungal activity against one or more indicator plant pathogenic fungi according to the dual culture test. Isolate TPL25 had the broadest antifungal spectrum of activity, and isolate TPL35 was active against 5 plant pathogenic fungi. Furthermore, culture filtrates of TPL25 and TPL35 exhibited greater than 80% growth inhibition against Sclerotinia sclerotiorum. We conclude that the endophytic fungal strains TPL25 and TPL35 are promising sources of bioactive compounds.

• Proceedings of the Microbiological Society of Korea Conference
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• 2006.05a
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• pp.129-131
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• 2006

Through molecular phylogenetic analysis using the nef gene sequences of HIV-l isolated from Korean registered in the NCBI GenBank together with 41 reference strains and 94 foreign isolates, we verified that most (${\sim}80%$) of Korean isolates belonged to subtype B and 78% of subtype B were clustered together exclusively of foreign isolates, and this cluster was named Korean clade subtype B ($K_cB$). Similarity study suggested that the $K_cB$ cluster was more homogeneous than and clearly distinctive from the non-Korean subtype B ($NK_cB$). Comparison of the consensus amino acid sequences of the $K_cB\;or\;NK_cB$ revealed characteristic $K_cB$ signature amino acid pattern comprised of 13 amino acid residues. The $K_cB$ signature amino acid residues were critical in separating the $K_cB$ ftom the $NK_cB$, since substitution of the $NK_cB$ sequences with $K_cB$ signature amino acids relocated them to the Koran clade, and vice versa. Synonymous and nonsynonymous substitution rate study suggested positive selection event for the $K_cB$.

• The Korean Journal of Mycology
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• v.42 no.4
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• pp.306-311
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• 2014

In this study, arbuscular mycorrhizal fungi (AMF) were isolated and cultivated from rhizospheres of various plants in Korea. Five species belonging to four genus were identified based on spore morphology and 18S rDNA sequence analysis: Acaulospora cavernata Claroideoglomus luteum, Diversispora aurantium, D. trimurales, Rhizophagus irregularis. These fungal species have not been cultivated or reported to date in Korea, Morphological description and phylogenetic analysis for each species were presented. This result could be useful for research of AMF diversity in Korea.

• Mycobiology
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• v.45 no.4
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• pp.344-352
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• 2017

During a survey of fungal diversity of the order Mucorales, three zygomycete isolates, CNUFC-YR113-1, CNUFC-KNU16-7, and CNUFC-BS1-1 were isolated from freshwater and soil samples in Korea. The strains were analyzed both morphologically and phylogenetically based on internal transcribed spacer and 28S rDNA gene sequences. Based on their morphology and phylogeny, the CNUFC-YR113-1 and CNUFC-KNU16-7 isolates were identified as Actinomucor elegans, and CNUFC-BS1-1 was identified as Mucor minutus. To the best of our knowledge, the species A. elegans and M. minutus, belonging to an undiscovered taxon, have not been previously described in Korea.

• Journal of Species Research
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• v.8 no.4
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• pp.351-364
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• 2019

Here we describe indigenous prokaryotic species in Korea, a total of 42 bacterial strains affiliated to the class Alphaproteobacteria isolated from various environmental samples: fermented vinegar, sea water, beach sand, fresh water, salt flats, moss, algae, activated sludge, and soil. From the high 16S rRNA gene sequence similarity (>98.7%) and formation of a robust phylogenetic clade with the closest species, it was determined that each strain belonged to predefined bacterial species. There is no official report that these 42 species included in Alphaproteobacteria in Korea: 15 species of 6 genera in the order Rhodospirillales, 12 species of 10 genera in the order Rhizobiales, 10 species of 8 genera in the order Rhodobacterales, 4 species of 4 genera in the order Sphingomonadales and 1 species of 1 genus in the order Caulobacterales. Gram reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and strain IDs are also described in the species description section.

• Animal Systematics, Evolution and Diversity
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• v.33 no.2
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• pp.136-139
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• 2017

The genus Iksookimia (Actinopterygii: Cypriniformes: Cobitidae) is a bottom-dwelling freshwater loaches, which are well-known as their endemism and high geographic variation. However, population genetic relationships among Iksookimia spp. have remained unclear due to a shortage of genetic markers that can be applied generally in the genus. Here, we developed high-resolving microsatellite markers using I. koreensis and I. longicorpa as representatives of Iksookimia species because of their wide distribution range and phylogenetic position. Ten of polymorphic microsatellite loci were isolated from Iksookimia koreensis and were successfully cross-amplified in I. longicorpa. The mean number of observed alleles per locus was about 10.4 (range, 2-17) for I. koreensis and about 13.2 (range, 2-24) for I. longicorpa. The loci, IK03 and IK08, deviated from the Hardy-Weinberg equilibrium in I. koreensis, after applying the Bonferroni correction. The microsatellite markers obtained in the present study will be useful to evaluate population genetic structure and to establish conservation strategies for I. koreensis and related Iksookimia species.

• ALGAE
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• v.36 no.3
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• pp.195-206
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• 2021

Increasing inputs of dissolved organic matter (DOM) to northern lakes is resulting in 'lake browning.' Lake browning profoundly affects phytoplankton community composition by modifying two important environmental drivers-light and nutrients. The impact of increased DOM on native isolates of red and green-pigmented cyanobacteria identified as Pseudanabaena, which emerged from a Dolichospermum bloom (Dickson Lake, Algonquin Provincial Park, Ontario, Canada) in 2015, were examined under controlled laboratory conditions. The genomes were sequenced to identify phylogenetic relatedness and physiological similarities, and the physical and chemical effects of increased DOM on cellular performance and competitiveness were assessed. Our study findings were that the isolated red and green phenotypes are two distinct species belonging to the genus Pseudanabaena; that both isolates remained physiologically unaffected when grown independently under defined DOM regimes; and that neither red nor green phenotype achieved a competitive advantage when grown together under defined DOM regimes. While photosynthetic pigment diversity among phytoplankton offers niche-differentiation opportunities, the results of this study illustrate the coexistence of two distinct photosynthetic pigment phenotypes under increasing DOM conditions.

• The Plant Pathology Journal
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• v.37 no.3
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• pp.258-267
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• 2021

Asian pear (Pyrus pyrifolia) is a widely cultivated and commercially important fruit crop, which is occasionally subject to severe economic losses due to latent viral infections. Thus, the aim of the present study was to examine and provide a comprehensive overview of virus populations infecting a major pear cultivar ('Singo') in Korea. From June 2017 to October 2019, leaf samples (n = 110) of pear trees from 35 orchards in five major pear-producing regions were collected and subjected to RNA sequencing. Most virus-associated contigs matched the sequences of known viruses, including apple stem grooving virus (ASGV) and apple stem pitting virus (ASPV). However, some contigs matched the sequences of apple green crinkle-associated virus and cucumber mosaic virus. In addition, three complete or nearly complete genomes were constructed based on transcriptome data and subjected to phylogenetic analyses. Based on the number of virus-associated reads, ASGV and ASPV were identified as the dominant viruses of 'Singo.' The present study describes the virome of a major pear cultivar in Korea, and looks into the diversity of viral communities in this cultivar. This study can provide valuable information on the complexity of genetic variability of viruses infecting pear trees.

• Journal of Species Research
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• v.10 no.2
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• pp.99-116
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• 2021

In 2018, as a subset study to discover indigenous prokaryotic species in Korea, a total of 18 unreported bacterial strains were discovered. From the high 16S rRNA gene sequence similarity (>98.8%) and formation of a robust phylogenetic clade, it was determined that each strain belonged an independent and predefined bacterial species. There were no official report that these 18 species were previously described in Korea; therefore, one strain of Williamsia, one strain of Rhodococcus, three strains of Microbacterium, three strains of Agromyces, one strain of Arthrobacter, one strain of Paeniglutamicibacter, one strain of Pseudarthrobacter, one strain of Nocardioides, one strain of Fibrella, one strain of Hymenobacter, one strain of Deinococcus, two strains of Fictibacillus, and one strain of Paenibacillus are described as unreported bacterial species in Korea. Gram reaction, basic biochemical characteristics, and colony and cell morphologies are described in the species description section.

• Parasites, Hosts and Diseases
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• v.57 no.4
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• pp.445-450
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• 2019

Human infections due to the monkey malaria parasite Plasmodium knowlesi is increasingly being reported from most Southeast Asian countries specifically Malaysia. The parasite causes severe and fatal malaria thus there is a need for urgent measures for its control. In this study, the level of polymorphisms, haplotypes and natural selection of full-length pkmsp8 in 37 clinical samples from Malaysian Borneo along with 6 lab-adapted strains were investigated. Low levels of polymorphism were observed across the full-length gene, the double epidermal growth factor (EGF) domains were mostly conserved, and non-synonymous substitutions were absent. Evidence of strong negative selection pressure in the non-EGF regions were found indicating functional constrains acting at different domains. Phylogenetic haplotype network analysis identified shared haplotypes and indicated geographical clustering of samples originating from Peninsular Malaysia and Malaysian Borneo. This is the first study to genetically characterize the full-length msp8 gene from clinical isolates of P. knowlesi from Malaysia; however, further functional characterization would be useful for future rational vaccine design.