• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.512-521
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• 2016

A bacterial strain was isolated from a soil sample collected on Jeju Island, Korea. The strain, designated WJ-2, exhibited a high xylanase activity, whereas cellulase activity was not detected. The 16S rRNA gene sequence of WJ-2 was highly similar to type strains of the genus Streptomyces. A neighbor-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain WJ-2 is phylogenetically related to Streptomyces atrovirens. Furthermore, DNA-DNA hybridization analysis confirmed that strain WJ-2 is a novel subspecies of Streptomyces atrovirens. The genomic DNA G+C content was 73.98 mol% and the major fatty acid present was anteiso-C15:0 (36.19%). The growth and xylanase production of strain WJ-2 were significantly enhanced by using soytone and xylan as nitrogen and carbon sources, respectively. Crude enzyme preparations from the culture broth of strain WJ-2 exhibited maximal total xylanase activities at pH 7.0 and $55^{\circ}C$. Thin-layer chromatography analysis revealed that the crude enzyme degrades beechwood xylan to yield xylobiose and xylotriose as the principal hydrolyzed end products.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.2125-2134
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• 2015

IrrE is a highly conserved global regulator in the Deinococcus genus and contributes to survival from high doses of UV radiation, ionizing radiation, and desiccation. Drad-IrrE and Dgob-IrrE from Deinococcus radiodurans and Deinococcus gobiensis I-0 each share 66% sequence identity. However, Dgob-IrrE showed a stronger protection phenotype against UV radiation than Drad-IrrE in the D. radiodurans irrE-deletion mutant (ΔirrE), which may be due to amino acid residues differences around the DNA-binding HTH domain. Site-directed mutagenesis was used to generate a Drad-IrrE A184S single mutant, which has been characterized and compared with the ΔirrE mutant complemented strain with Drad-irrE, designated ΔirrE-E. The effects of the A184S mutation following UV radiation and mitomycin C (MMC) shock were determined. The A184S mutant displayed significantly increased resistance to UV radiation and MMC shock. The corresponding A184 site in Dgob-IrrE was inversely mutated, generating the S131A mutant, which exhibited a loss of resistance against UV radiation, MMC shock, and desiccation. qPCR analysis revealed that critical genes in the DNA repair system, such as recA, pprA, uvrA, and ddrB, were remarkably induced after UV radiation and MMC shock in the ΔirrE-IE and A184S mutants. These data suggested that A184S improves the ability against UV radiation and MMC shock, providing new insights into the modification of IrrE. We speculated that the serine residue may determine the efficiency of DNA binding, leading to the increased expression of IrrE-dependent genes important for protection against DNA damage.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1883-1895
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• 2018

Alcohol dependence is a global public health problem, yet the mechanisms of alcohol dependence are incompletely understood. The traditional view has been that ethanol alters various neurotransmitters and their receptors in the brain and causes the addiction. However, an increasing amount of experimental evidence suggests that gut microbiota also influence brain functions via gut-to-brain interactions, and may therefore induce the development of alcohol use disorders. In this study, a rat model of alcohol dependence and withdrawal was employed, the gut microbiota composition was analyzed by high-throughput 16S rRNA gene sequencing, and the metagenome function was predicted by PICRUSt software. The results suggested that chronic alcohol consumption did not significantly alter the diversity and richness of gut microbiota in the jejunum and colon, but rather markedly changed the microbiota composition structure in the colon. The phyla Bacteroidetes and eight genera including Bacteroidales S24-7, Ruminococcaceae, Parabacteroides, Butyricimonas, et al were drastically increased, however the genus Lactobacillus and gauvreauii in the colon were significantly decreased in the alcohol dependence group compared with the withdrawal and control groups. The microbial functional prediction analysis revealed that the proportions of amino acid metabolism, polyketide sugar unit biosynthesis and peroxisome were significantly increased in the AD group. This study demonstrated that chronic alcohol consumption has a dramatic effect on the microbiota composition structure in the colon but few effects on the jejunum. Inducement of colonic microbiota dysbiosis due to alcohol abuse seems to be a factor of alcohol dependence, which suggests that modulating colonic microbiota composition might be a potentially new target for treating alcohol addiction.

• Korean Journal of Plant Taxonomy
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• v.42 no.1
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• pp.91-97
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• 2012

Two naturalized plants belonging to Plantaginaceae and Labiatae are newly recorded for Korean flora. Nuttallanthus canadensis (L.) D. A. Sutton, a taxon of the unrecorded genus Nuttallanthus (Plantaginaceae), was founded in Seogwipo-si, Jeju-do. This species can be distinguished from the Linaria species by its corolla with a pale blue to a pale purple color, a lower lip longer than the upper lip and seed with 4-7 angles when cross-sectioned. Lamium purpureum var. hybridum (Vill.) Vill. was found in Gwangju Metropolitan city, Jeongeup-si, Jeollabuk-do and Gochang-gun, Jeollanam-do. It can be distinguished from L. purpureum L. by its irregularly dentate bracts and upper lips 3-4 mm in length. New Korean names were given, as Sol-lip-hae-rancho to Nuttallanthus canadensis (L.) D. A. Sutton and Eu-reop-gwang-dae-na-mul to Lamium purpureum var. hybridum (Vill.) Vill. In addition, their descriptions, photos, illustrations and keys to related genera and species are provided here.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.80-80
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• 2018

Hosta is a genus of the family Asparagaceae and distributed in East Asia. There are six Hosta species (Hosta capitata (Koidz.) Nakai, H. clausa Nakai, H. jonesii M.G.Chung, H. minor (Baker) Nakai, H. venusta F.Maek., and H. yingeri S.B.Jones) native to Korea and among them, four species (H. minor, H. jonesii, H. venusta and H. yingeri) are endemic to the Korea peninsula. Hosta is generally propagated by seed, crown division or tissue culture. However, tissue culture is a more efficient method to mass proliferation, a new cultivar development and disease-free plantlet production in a limit time. Hence, we conducted this study to evaluate the influence of various plant growth regulators (PGRs) treatments on the induction of callus and somatic embryo of the six Hosta species. Leaf, petiole and root were used to select optimum tissue culture explants. Petiole explants thus only were used for callus induction and somatic embryogenesis with TDZ (0.1, 0.5 or 1.0mg/L) and NAA (0.1 or 0.5 mg/L) combinations. After 12 weeks of culture, the highest rate of somatic embryogenesis was achieved on modificated MS medium containing 1.0 mg/L TDZ and 0.1 mg/L NAA in H. capitata and H. minor (15.5%, respectively), 0.1 or 0.5 mg/L TDZ and 0.1 mg/L NAA in H. jonesii (22.2%), 1.0 mg/L TDZ and 0.5 mg/L NAA in H. yingeri (26.7%), and 0.1 mg/L TDZ and 0.5 mg/L NAA in H. venusta (53.3%). H. clausa showed very low effect on somatic embryogenesis by PGRs; 2.2%. There was interspecies difference to PGRs respond for callus and somatic embryo induction. Regenerated multiple shoots and plantlet of H. minor, H. jonesii, H. venusta and H. yingeri were obtained via somatic embryogenesis.

• Journal of Mushroom
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• v.13 no.3
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• pp.243-249
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• 2015

Agaricus bitorquis is an edible white mushroom of the genus that is cultivated at high temperature($25{\pm}1^{\circ}C$) unlike A. bisporus is cultivate at $16{\pm}2^{\circ}C$. Unlike Agaricus bisporus, an edible white A. bitorquis mushroom is cultivated at high temperature ($25{\pm}1^{\circ}C$). Most farmers cultivate this mushroom for a long cultivation period in Korea. For this reason, we made heterokayons to develop a new cultivar that generate fruitbodies for short cultivation period. Over one hundred SSIs(single spores isolates) were collected from selected A. bitorquis ASI1151 and ASI1349 strains. Seventy-three SSIs were germinated on CDA(compost dextrose agar) media after 20 days (minimum) or 83 days (maximum) incubation under different media condition. The mycelial growth rate of germinated SSIs was different. 9 homokaryons in ASI 1151 and 11 homokaryons in ASI 1349 from SSIs were selected by OPN-02 primer in RAPD analaysis. Also this primer was used to select heterokaryon that cross among each homokaryon with compatible locus. Therefore 44 compatible matings were confirmed of 99 crossed lines.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.1
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• pp.1-8
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• 2012

The objective of the present study was carried out to clarify the effects of deep sea water on the growth and maturation of $Porphyra$ (Rhodophyta, Bangiales). Foliose thalli for indoor culture were collected from Yeongok ($P.$ $okamurae$) in Gangwon Prefecture, Tongyeong ($P.$ $suborbiculata$ f. $latifolia$) and Namhae ($P.$ $yezoensis$ f. $narawaensis$) in Gyongnam Prefecture respectively. Monospores were cultured at five temperatures (5, 10, 15, 20 and $25^{\circ}C$) with a photon irradiance of $80{\mu}m^{-2}s^{-1}$ under photoperiods of 14L:10D and 10L:14D in surface, deep and mixed seawater in respectively. The fast growth of foliose thalli were observed in $P.$ $suborbiculata$ f. $latifolia$ cultured at deep seawater under $15^{\circ}C$ and 10L:14D. In three species, the optimum growth occurred at 10 and $15^{\circ}C$ under deep and mixed seawater and short day-length. In general, monospores from the cultured thalli were liberated within three weeks after incubation under $10-25^{\circ}C$ and both photoperiods. From the result of this study, deep seawater is considered that the natural species of the genus $Porphyra$ can be useful for the development as the new cultivars.

• Korean Journal of Ichthyology
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• v.28 no.2
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• pp.116-120
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• 2016

A specimen of Cocotropus masudai (41.2 mm in standard length), belonging to the family Aploactinidae, was firstly collected from the eastern coastal waters of Jejudo Island, Korea by using a fish trap in July 2011. This species is characterized by having the following morphological traits: XII, 9 dorsal fin rays; I, 8 anal fin rays; 12 pectoral fin rays; I, 3 pelvic fin rays; five preopecular spines; five sensory pores present on lower jaw and isthmus tip beyond fifth sensory pore. This species is similar to C. izuensis except for the number of preopercular spines (five in C. izuensis vs. four in C. masudai) and the anterior position of the isthmus (well beyond the fifth lower jaw sensory pore vs. the tip mostly reaching to the pore). In Korea, C. masudai can be easily distinguished from the Erisphex pottii in having the dorsal fin with nine soft rays (vs. 10~14 for Erisphex pottii), anal fin with seven soft rays (vs. 10~13) and pelvic fin with three soft rays (vs. two). We propose new Korean names, "Dot-chi-sok" and "Dot-chi" for the genus and species, respectively.

• The Korean Journal of Mycology
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• v.26 no.4 s.87
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• pp.574-582
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• 1998

Five basidiocarps of Pholiota species have been collected from the areas of BubJu Temple for last two years, and identified to those of P. adiposa or Pholiota species. The taxonomy of these basidiocarps with the morphological aspects was compared with the analysis obtained from the polymorphisms of PCR-RAPD bands made after reacted with the random primers. The polymorphic variations were observed within the species of the basidiocarps, but not between genomic DNA's of the mycelia obtained and the basidiocarps. Several different bands made from the primers (28 and 36) in PCR-RAPD reactions were identified within the genus of Pholiota and speculated to be specific for the individual basidiocarp of P. adiposa collected. The primers employed here were considered to be very useful for distinguishing the individual isolates or basidiocarps collected from the fields. Also, the basidiospores were obtained from the sporeprints of the above basidiocarps as a simple agar and confirmed with observations of clamp connection under microscopes. The matings of them indicated the 'tetrapolar' type, being different from the 'bipolar' type reported by Japanese basidiocarps of P. adiposa or P. nameko. Based on our work, the edible fungi collected were speculated to be a new breeding resource for those of Pholiota commercialized in Japan.

• The Korean Journal of Mycology
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• v.24 no.4 s.79
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• pp.265-273
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• 1996

Fleshy fungi were collected during field trips to mountain areas throughout the country from October in 1994 to June in 1995. Through the observation and identification of specimens belonging to the wood-rotting fungi of the Aphyllophorales, one genus, Phlebiopsis, and six species, Athelia bombacina, Ceraceomyces sublaevis, Hyphoderma sibiricum, Hyphodontia arguta, Phlebiopsis gigantea, and Radulomyces confluens were confirmed as new corticioid fungi to Korea and are registered here with descriptions.