• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.771-779
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• 2012

The bacterial diversity of the continental shelf sediment in the Yellow Sea was investigated by the cloning and sequencing of PCR-amplified 16S rRNA genes. The majority of the cloned sequences were distinct phylotypes that were novel at the species level. The richness estimator indicated that the sediment sample might harbor up to 32 phylum-level taxa. A large number of low-abundance, phylum-level taxa accounted for most of the observed phylogenetic diversity at our study site, suggesting that these low-abundance taxa might play crucial roles in the shelf sediment ecosystem.

• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.180-184
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• 2016

In this study, we evaluated complex media with influent sewage water (ISW) to isolate novel taxa of bacteria. It was possible to cultivate 13 genera using the complex media with ISW. Additionally, more diverse genera were identified at 37℃ than at 25℃, using the complex media with ISW. Total 12 strains of 179 bacterial isolates were shared less than 97% 16S rRNA gene sequence similarities with any known species. These isolates could be assigned to genera Tessaracoccus, Paracoccus, or Candidimonas (or Paralcaligenes).

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.240-250
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• 2017

This taxonomic study sought to detect and describe diatom species not yet recorded in Korea. The study was conducted at three islands located off the western coast of Korea, Wido Island near Buan, Wonsando Island near Boryeong and Dekjeokdo Island near Incheon. Diatoms were collected from the bottom, stone, macrophytes and other substrates in water bodies, which are affected by seawater. Fifteen naviculoid taxa are described. Of these, 13 are novel to Korea. The genus Navicula has nine species; Navicula alineae Lange-Bertalot, N. ammophila Grunow, N. cariocincta Lange-Bertalot, N. elegantoides Hustedt, N. longicephala Hustedt, N. normaloides Cholnoky, N. notha Wallace, N. novaesiberica Lange-Bertalot, N. riediana Lange-Bertalot & U. Rumrich. The genus Craticula has four species; Craticula buderi (Hustedt) Lange-Bertalot, C. halophila (Grunow) D.G. Mann, C. riparia (Hustedt) Lange-Bertalot and C. riparia var. mollenhaueri Lange-Bertalot.

• Mycobiology
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• v.46 no.3
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• pp.205-214
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• 2018

The order Mucorales, the largest in number of species within the Mucoromycotina, comprises typically fast-growing saprotrophic fungi. During a study of the fungal diversity of undiscovered taxa in Korea, two novel mucoralean strains, CNUFC-GWD3-9 and CNUFC-EGF1-4, were isolated from specific habitats including freshwater and fecal samples, respectively. On the basis of their morphological characteristics and sequence analyses of internal transcribed spacer and large subunit ribosomal DNA, the CNUFC-GWD3-9 and CNUFC-EGF1-4 isolates were confirmed to be Gilbertella persicaria and Pilobolus crystallinus, respectively. It is ecologically, pathologically, and mycologically significant to find such rare zygomycetous fungi in such specific habitats.

• Journal of Environmental Health Sciences
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• v.42 no.2
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• pp.126-132
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• 2016

Objectives: This study aims to provide basic data regarding the bacterial total plate count in the atmospheric environment for related studies. Methods: Total plate count and the identification of culturable bacteria in the atmospheric environment in Incheon took place in 2015 using periodic survey. Correlationship analysis was performed between the number of culturable bacteria and environmental elements. In addition, an estimation of novel bacterial species was undertaken using the similarities and phylogenetic tree based on the 16S rRNA gene. Results: The total plate count of culturable bacteria was on average $176CFU/m^3$, and did not exceed $610CFU/m^3$ in the atmospheric environment. Periodic monthly measuring of total plate count was highest in June at $293CFU/m^3$, while the lowest was in July at $125CFU/m^3$. Furthermore, as a result of the identification of culturable bacteria, the genera Arthrobacter and Kocuria were dominant, while novel bacterial taxa that belong to the genera Chryseobacterium and Herbiconiux were separated. Conclusion: The total number of culturable bacteria from the atmospheric environment in Korea is on average $176CFU/m^3$. In addition, the genera Arthrobacter and Kocuria dominate. The presence of novel bacterial taxa are expected in the atmospheric environment, such as belonging to the genera Chryseobacterium and Herbiconiux.

• Korean Journal of Environmental Biology
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• v.29 no.3
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• pp.154-161
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• 2011

The species diversity of Betaproteobacteria in the Sumunmulbengdui Wetland Area of Jeju Island was studied using culture based techniques, and candidates for novel taxa were screened. Twenty two novel bacterial strains belonging to Betaproteobacteria were isolated, which could be assigned to 16 genera of 4 families, namely Burkholderiaceae (3 strains), Comamonadaceae (8 strains), Oxalobacteraceae (5 strains), Neisseriaceae (5 strains), and an unassigned group belonging to Burkholderiales (1 strain) based 16S rRNA gene sequences. The genus Chromobacterium contained three candidates of novel species, and each of the genera Burkholderia, Comamonas, Pelomonas and Herbaspirillum contained two candidates respectively. Through the analysis of membrane fatty acid profiles and physiological properties using API 20NE as well as morphological and cultural properties, each of the isolates was found to form potentially novel species. Brief description of 22 potential candidates for new species or subspecies is given accordingly.

• Mycobiology
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• v.48 no.4
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• pp.245-251
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• 2020

During a survey of putative fungal pathogens infecting oak trees in the Gangwon Province of the Republic of Korea, a fungus resembling a Ceratocystis sp. was repeatedly isolated from natural wounds on Quercus variabilis. Morphological comparisons and DNA sequence comparisons based on partial β-tubulin and TEF-1α gene regions showed that the fungus resided in a distinct lineage. This novel Ceratocystis species is described here as C. quercicola sp. nov. This is the first novel species of Ceratocystis to be reported from Korea. A pathogenicity test showed that it can cause lesions on inoculated trees but that it had a very low level of aggressiveness. The discovery of this fungus suggests that additional taxa residing in Ceratocystis are likely to be discovered in Korea in the future.

• Mycobiology
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• v.49 no.1
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• pp.46-53
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• 2021

In a study of the fungal diversity on Ulleung Island in Korea, three novel strains of Penicillium were isolated. Different sites on Ulleung Island were selected for collecting endophytic fungi, and three endophytic fungal strains showed unique morphological characteristics. DNA sequence of the internal transcribed spacer, β-tubulin, calmodulin, and RNA polymerase II second largest subunit regions of the strains were analyzed and they showed unique taxonomic position from the other species of Penicillium section Sclerotiora. The new strains were named Penicillium ulleungdoense sp. nov. As the novel endophytic Penicillium taxa were discovered in a unique environment, the data could be meaningful for understanding the geographical distribution of Ascomycetes on Ulleung Island.

• Journal of Microbiology and Biotechnology
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• v.29 no.5
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• pp.731-738
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• 2019

Endophytic fungi are an important component of plant microbiota, and have the excellent capacity for producing a broad variety of bioactive metabolites. These bioactive metabolites not only affect the survival of the host plant, but also provide valuable lead compounds for novel drug discovery. In this study, forty-two endophytic filamentous fungi were isolated from Ficus elastica leaves, and further identified as seven individual taxa by ITS-rDNA sequencing. The antimicrobial activity of these endophytic fungi was evaluated against five pathogenic microorganisms. Two strains, Fes1711 (Penicillium funiculosum) and Fes1712 (Trichoderma harzianum), displayed broad-spectrum bioactivities. Our following study emphasizes the isolation, identification and bioactivity testing of chemical metabolites produced by T. harzianum Fes1712. Two new isocoumarin derivatives (1 and 2), together with three known compounds (3-5) were isolated, and their structures were elucidated using NMR and MS. Compounds 1 and 2 exhibited inhibitory activity against Escherichia coli. Our findings reveal that endophytic fungi from the rubber tree F. elastica leaves exhibit unique characteristics and are potential producers of novel natural bioactive products.

• ALGAE
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• v.37 no.1
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• pp.1-14
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• 2022

Cyanobacteria are distributed worldwide, and many new cyanobacterial species are discovered in tropical region. The Nostoc-like genus Amazonocrinis has been separated from the genus Nostoc based on polyphasic methods. However, species diversity within this genus remains poorly understood systematically because only one species (Amazonocrinis nigriterrae) has been described. In this study, two novel strains (NUACC02 and NUACC03) were isolated from moist rice field soil in Thailand. These two strains were characterized using a polyphasic approach, based on morphology, 16S rRNA phylogenetic analysis, internal transcribed spacer secondary structure and ecology. Phylogenetic analyses based on 16S rRNA gene sequences confirmed that the two novel strains formed a monophyletic clade related to the genus Amazonocrinis and were distant from the type species A. nigriterrae. The 16S rRNA gene sequence similarity (<98.1%) between novel strains and all other closely related taxa including the Amazonocrinis members exceeded the cutoff for species delimitation in bacteriology, reinforcing the presence of a new Amazonocrinis species. Furthermore, the novel strains possessed unique phenotypic characteristics such as the presence of the sheath, necridia-like cells, larger cell dimension and akinete cell arrangement in long-chains and the singularity of D1-D1', Box-B, V2, and V3 secondary structures that distinguished them from other Amazonocrinis members. Considering all the results, we described our two strains as Amazonocrinis thailandica sp. nov. in accordance with the International Code of Nomenclature for Algae, Fungi and Plants.