• Journal of Applied Biological Chemistry
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• v.50 no.4
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• pp.196-201
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• 2007

An intracellular invertase was purified to homogeneity from the cell extract of an alkalophilic and thermophilic Bacillus sp. TA-11, which was classified as a new species belonging to Bacillus cereus based on chemotaxanomic and phylogenetic analyses. The purified enzyme with a recovery of 26.6% was determined to be a monomeric protein with a molecular weight of 23 kDa by SDS-PAGE and 26 kDa by gel filtration. The maximum enzyme activity was observed at pH 7.0 and $50^{\circ}C$, and the purified enzyme was stable at the pH range of 5.0 to 8.0 and below $60^{\circ}C$. $K_m$ and $V_{max}$ values of the enzyme for sucrose were 370 mM and 3.0 ${\mu}M$ per min, respectively. The enzyme activity was significantly inhibited by bivalent metal ions ($Hg^{2+}$, $Cd^{2+}$ and $Cu^{2+}$) and sugars (glucose and fructose).

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.26-35
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• 2020

BACKGROUND: Microbes that govern a unique biochemical process of oxidizing ammonia into dinitrogen gas, such as anaerobic ammonium oxidation (anammox) have been reported to play a pivotal role in agricultural soils and in oceanic environments. However, limited information for anammox bacterial abundance and distribution in the terrestrial habitats has been known. METHODS AND RESULTS: Phylogenetic and next-generation sequencing analyses of bacterial 16S rRNA gene were performed to examine potential anammox bacteria in paddy soils. Through clone libraries constructed by using the anammox bacteria-specific primers, some clones showed sequence similarities with Planctomycetes (87% to 99%) and anammox bacteria (94% to 95%). Microbial community analysis for the paddy soils by using Illumina Miseq sequencing of 16S rRNA gene at phylum level was dominated by unclassified Bacteria at 33.2 ± 7.6%, followed by Chloroflexi at 20.4 ± 2.0% and Acidobacteria at 17.0 ± 6.5%. Planctomycetes that anammox bacteria are belonged to was 1.5% (± 0.3) on average from the two paddy soils. CONCLUSION: We suggest evidence of anammox bacteria in the paddy soil. In addition to the relatively well-known microbial processes for nitrogen-cycle, anammox can be a potential contributor on the cycle in terrestrial environments such as paddy soils.

• Animal Systematics, Evolution and Diversity
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• v.31 no.4
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• pp.209-246
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• 2015

Morphological features of larvae and pupae of twelve species of Simulium (Simulium) from Korea are investigated and redescribed. Detailed descriptions of immature stages of each species are provided with photographs. For the Korean members of subgenus Simulium, combinations of the following characteristics can be used to separate them from other Korean subgenera: larval abdomen without a pair of conical-shaped ventral tubercles; postgenal cleft variously shaped, viz., miter shaped, spearhead, bullet shaped or triangular; rectal papillae 3 simple lobe or compound lobes; pupal gill of 6-16 filaments; cocoon shoe, boot or slipper shaped; and head trichomes 3 pairs (1 facial+2 frontal). Habitat information and other ecological aspects of each species are provided. Updated keys to larvae and pupae of the Korean species of the subgenus Simulium are also provided to facilitate species identification. Taxonomic treatment based on external morphologies of larvae and pupae of Korean species of the subgenus Simulium are focused and included in this study. To understand their interspecific relationships, phylogenetic analyses using multiple data from molecule, morphology, and ecology are warranted in future research. Also continued exploration for new character systems is needed to establish more stable boundaries for subgenus and species delimitations.

• Mycobiology
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• v.34 no.2
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• pp.45-55
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• 2006

Although Fursarium oxysporum causes diseases in economically important plant hosts, identification of F. oxysporum formae speciales has been difficult due to confusing phenotypic classification systems. To resolve these complexity, we evaluated genetic relationship of nine formae speciales of F. oxysporum with random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), and translation elongation factor-l alpha ($EF-1{\alpha}$) gene. In addition, the correlation between mycotoxin content of fusaric acid and isolates based on molecular marker data was evaluated using the modified Mantel's test. According to these result, these fusaric acid-producing strains could not identify clearly, and independent of geographic locations and host specificities. However, in the identification of F. oxysporum formae speciales, especially, AFLP analysis showed a higher discriminatory power than that of a the RAPD and $EF-1{\alpha}$ analyses, all three techniques were able to detect genetic variability among F. oxysporum formae speciales in this study.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.150-155
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• 2018

Two siphonous green algae were collected from the eastern coast of Korea. These species share the typical features of Derbesia sporophytes, such as erect and prostrate siphonous filaments and the presence of basal septum in lateral branches. One is characterized by the combined features of a relatively small tufted sporophytic thalli arising from a rhizoidal base, subdichotomously branched filaments with a basal septum and one pyrenoid per subspherical to lenticular chloroplast. The other shows a larger sporophytic thallus, sparsely subdichotomously branched filaments with a basal septum and one pyrenoid per spherical chloroplast. In a phylogenetic tree based on rbcL sequence, the two above-mentioned Korean algae nest in the same clades as Derbesia minima and D. indica, respectively. The genetic distance between the sequences within the clades was 0.5-0.8%, which is considered to be included in the intra-specific range for the genus. These two siphonous Korean algae are identified as D. minima and D. indica, respectively, based on the morphological and molecular analyses. These species are newly recorded in the Korean marine algal flora herein.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1324-1330
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• 2017

Complete genome sequences of three new plant RNA viruses, Spinach deltapartitivirus 1 (SpDPV1), Spinach amalgavirus 1 (SpAV1), and Spinach latent virus (SpLV), were identified from a spinach (Spinacia oleracea) transcriptome dataset. The RNA-dependent RNA polymerases (RdRps) of SpDPV1, SpAV1, and SpLV showed 72%, 53%, and 93% amino acid sequence identities with the homologous RdRp of the most closely related virus, respectively, suggesting that SpDPV1 and SpAV1 were novel viruses. Sequence similarity and phylogenetic analyses revealed that SpDPV1 belonged to the genus Deltapartitivirus of the family Partitiviridae, SpAV1 to the genus Amalgavirus of the family Amalgaviridae, and SpLV to the genus Ilarvirus of the family Bromoviridae. Based on the demarcation criteria, SpDPV1 and SpAV1 are considered as novel species of the genera Deltapartitivirus and Amalgavirus, respectively. This is the first report of these two viruses from spinach.

• Fisheries and Aquatic Sciences
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• v.20 no.10
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• pp.26.1-26.9
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• 2017

Fishes in genus Sardinella are small pelagic species, which plays an important role in marine ecosystem as the first consumer. Those species are also commercially important, whose total catch reaches 278,600 tons in 2011 in Indonesia, but their identification has been difficult for their morphological similarity. In this study, we reported Sardinella jussieu for the first time in Indonesian coastal area (Banten Bay, Indonesia, $6^{\circ}\;0^{\prime}\;50.00^{{\prime}{\prime}}\;S-106^{\circ}\;10^{\prime}\;21.00^{{\prime}{\prime}}\;E$). We were able to confirm the species by both its morphological characteristics including the black spot at dorsal fin origin, the dusky pigmentation at caudal fin, 31 total scute numbers, and DNA sequence identity in the GenBank database by the molecular analysis. Its total mitochondrial genome was determined by the combination of next-generation sequencing and typical PCR strategy. The total mitochondrial genome of Sardinella jussieu (16,695 bp) encoded 13 proteins, 2 ribosomal RNAs, 22 transfer RNAs, and the putative control region. All protein-coding genes started with ATG and typical stop codon and ended with TAA or TAG except for ND4 in which AGA is used. Phylogenetic analyses of both COI region and full mitochondrial genome showed that S. jussieu is most closely related to Sardinella albella and Sardinella gibbosa

• Mycobiology
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• v.43 no.3
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• pp.203-209
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• 2015

Three new fungal species of the genus Mortierella, Mortierella zychae, Mortierella ambigua, and Mortierella indohii, have been reported in Korea. The fungi were encountered during a study on the fungal community of soil samples collected from different locations in Korea. The species were identified based on molecular and morphological analyses. This study presents detailed descriptions of the morphological observations and molecular phylogenetic analysis of these three fungi. All three species were found to be sensitive to triphenyltetrazolium chloride staining. M. zychae demonstrated the highest intensity of mycelial staining, indicating that this species has the highest potential to produce arachidonic acid of the three species. The staining results indicated that the newly recorded species could potentially be useful for arachidonic acid production.

• The Korean Journal of Mycology
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• v.48 no.2
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• pp.103-116
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• 2020

Freshwater ecosystems provide a complex environment for microorganisms. In this study, we isolated diverse fungal strains from plant litter in freshwaters. These strains were identified using molecular phylogenetic analyses of rDNA and/or other gene sequences (TUB, GAPDH, and EF1). In addition, we examined their morphological characteristics by microscopy and cultural characteristics on several media. We identified six previously unrecorded Sordariomycetes species in Korea, i.e., Colletotrichum godetiae, Discosia rubi, Robillarda sessilis, Monochaetia dimorphospora, Idriella lunata, and Phialemoniopsis endophytica. Of these, D. rubi and M. dimorphospora exhibited high extracellular amylase, lipase, and protease activities, suggesting that these fungal isolates might play an important role as decomposers in freshwater ecosystems. Plant litter could thus be a good source for isolating and investigating previously undocumented fungal species in freshwater environments.

• Mycobiology
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• v.48 no.4
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• pp.263-275
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• 2020

Phlebopus spongiosus is a well-known edible ectomycorrhizal mushroom indigenous to southern Vietnam. The mushroom specimens collected from northern Thailand in this study were identified as P. spongiosus. This identification was based on morphological characteristics and the multi-gene phylogenetic analyses. Pure cultures were isolated and the relevant suitable mycelial growth conditions were investigated. The results indicated that the fungal mycelia grew well on L-modified Melin-Norkans, and Murashige and Skoog agar all of which were adjusted to a pH of 5.0 at 30 ℃. Sclerotia-like structures were observed on cultures. The ability of this mushroom to produce fruiting bodies in the absence of a host plant was determined by employing a bag cultivation method. Fungal mycelia completely covered the cultivation substrate after 90-95 days following inoculation of mushroom spawn. Under the mushroom house conditions, the highest amount of primordial formation was observed after 10-15 days at a casing with soil:vermiculite (1:1, v/v). The primordia developed into a mature stage within one week. Moreover, identification of the cultivated fruiting bodies was confirmed by both morphological and molecular methods. This is the first record of P. spongiosus found in Thailand and its ability to form fruiting bodies without a host plant.