• Ecology and Resilient Infrastructure
• /
• v.3 no.1
• /
• pp.62-69
• /
• 2016

Narrow-mouth frog (Kaloula borealis) is the only amphibian species of genus Kaloula living in South Korea. They are designated and managed as endangered class II wildlife by the Ministry of Environment, Korea. Therefore, there is a desperate need of a habitat restoration study to prevent the extinction of narrow-mouth frog. This study is primarily for the purpose of presenting the direction and practical applications to restore damaged narrow-mouth frog habitats or to suggest alternative habitat options. The habitat suitability index (HSI) of narrow-mouth frog was applied to the research area in Mokpo City of Jeollanam-do Province, in order to present a new narrow-mouth frog habitat. We analyzed the research area based on historical contexts, ecological environment, ecology, and habitat requirements. The research area was divided into the core, buffer, and transition zones according to UNESCO MAB (Man and Biosphere) to establish local land-use plans. As for the foundation of the plan, we divided the habitat composition of the core, where narrow-mouth frog live in, into wetland (spawning area), grassland (shelter and feeding grounds), and forestland (feeding ground). We had a comparative analysis of habitat suitability in pre and post planning of narrow-mouth frog habitat restoration. For the validation study of habitat restoration plans, the future research should be on the composition of test-bed, continuous monitoring, and scientific habitat maintenance.

• Research in Plant Disease
• /
• v.26 no.3
• /
• pp.179-182
• /
• 2020

In July 2018, a serious rust symptom was found throughout the fringe trees planted in Gangjin-gun, Korea. Yellow and brown spots were observed on the adaxial (topside) surface of the collected fringe tree leaves, and yellow color aecia were observed on the abaxial (underside) surface leaves. The size of aeciospore and urediniospores of JCK-KCFR1 strain were measured to 41.2 ㎛ (Φ) and 28.84 ㎛ (Φ) with a light microscope. Phylogenetic analysis of the small subunit rRNA, internal transcribed spacer, and large subunit rRNA region indicated that JCK-KCFR1 strain is novel species of the genus Puccinia and closely related to Puccinia kusanoi, which has been reported a rust pathogen on bamboo. In May 2019, rust symptoms were also discovered on the bamboo leaves planted around the fringe tree on Muwisa-ro, and their telia and teliospores were observed on the abaxial leaf surfaces of the bamboo with 100% sequence homology with the rust of the fringe tree. This is the first report that Puccinia sp. JCK-KCFR1 is a new species that requires both primary (fringe tree) and alternative (bamboo) host plants to complete its life cycle in Korea.

• Parasites, Hosts and Diseases
• /
• v.27 no.4
• /
• pp.253-260
• /
• 1989

Metacercariae of the genus Stictodora encysted in the head tissue of Acanthogobius navimanus (the gobies) caught at Sachun-gun, Kyongnam Province, were identified to be Stictodora Zari Yamaguti, 1939 (Trematoda: Heterophyidae), a new parasite fauna in Korea. The metacercariae were 0.39∼,0.43 mm by 0.32∼0.35 mm in size, long elliptical, and with a thin and transparent cyst wall. Total 200 metacercariae were collected from 50 gobies. In order to obtain adult worms two kittens and a Puppy were infected each with 34∼100 metacercariae, and total 33 adults were recovered between the day 4 and day 8 post-infection. The S. sari adults measured 0.95∼1.18 mm long and 0.26∼0.32 mm wide and the eggs in uteri 0.028∼0.033 mm by 0.017∼0.020 mm. The most characteristic morphological feature of these flukes was the presence of a gonotyl and gonotyl spines arranged in two groups; densely crowded group of 30~40 spines and linearly-arranged one of 30∼40 spines, together of which made a comma(or reversed comma) shape along the lateral margin of the gonotyl. It has been proved by this study that 5. sari is distributed in southern coasts of Korea.

• Korean Journal of Veterinary Research
• /
• v.48 no.4
• /
• pp.441-449
• /
• 2008

The genus Lactobacillus is the largest of the genera included in lactic acid bacteria and is associated with mucosal membranes of human and animal. Only a few Lactobacillus plasmid-encoded functions have been discovered and used. In this study, a novel plasmid (pILR091) was isolated from a wild L. reuteri isolated from pig and described the characteristics of its replicons, genetic organization, and relationship with other plasmids. After digestion of the plasmid, pILR091, with SalI, plasmid DNA was cloned into the pQE-30Xa vector and sequenced. The complete sequence was confirmed by the sequencing of PCR products and analyzed with the Genbank database. The isolate copy number and stability were determined by quantitative-PCR. The complete sequence of L. reuteri contained 7,185 nucleotides with 39% G-C content and one cut site by two enzymes, SalI and HindIII. The similar ori sequence of the pC194- rolling circle replication family (TTTATATTGAT) was located 63 bp upstream of the protein replication sequence, ORF 1. Total of five ORFs was identified and the coding sequence represented 4,966 nucleotides (70.4%). ORF1 of pILR091 had a low similarity with the sequence of pTE44. Other ORFs also showed low homology and E-values. The average G-C content of pILR091 was 39%, similar with that of genomic DNA. The copy number of pILR091 was determined at approximately 24 to 25 molecules per genomic DNA. These results suggested that pILR091 might be a good candidate to construct a new vector, which could be used for cloning and expression of foreign genes in lactobacilli.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2001.11a
• /
• pp.46-53
• /
• 2001

A commensal thermophile, Symbiobacterium toebii, isolated from hay compost (toebii) in Korea commensally interacted with a thermophilic Geobacillus toebii sp. nov., which was a new species within the genus Geobacillus on the basis of the phenotypic traits and molecular systematic data. S. toebii required the crude extracts and/or culture supernatant of the Geobacillus toebii for axenic growth and could grow on the temperature between 45 and $70^{\circ}C$ (optimum: $60^{\circ}C$; 2.4 h doubling time) and pH 6.0 and 9.0 (optimum: pH 7.5). The G+C content of the genomic DNA was $65 mol\%$, and the major quinones were MK-6 and MK-7. A phylogenetic analysis of its 16S rDNA sequence indicated that Symbiobacterium toebii was closely related with solely reported Symbiobacterium thermophilum. The presence of the commensal thermophile 16S rDNA and accumulation of indole in all the enriched cultures indicate that Symbiobacterium toebii is widely distributed in the various soils. The genome of S. toebii constituted a circular chromosome of 3,280,275 base pairs and there was not an extra-chromosomal element (ECE). It contained about 4,107 predicted coding sequences. Of these protein coding genes, about $45.6\%$ was encoded well-known proteins and annotated the functional assignment of 1,874 open reading frames (ORFs), and the rest predicted to have unknown functions. The genes encoding thermostable tyrosine phenol-lyase and tryptophan indole-lyase were cloned from the genomic DNA of S. toebii and the enzymatic production of L-tyrosine and L-tryptophan was carried out with two thermostable enzymes overexpressed in recombinant E. coli.

• Microbiology and Biotechnology Letters
• /
• v.44 no.4
• /
• pp.512-521
• /
• 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
• /
• v.25 no.12
• /
• pp.2125-2134
• /
• 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
• /
• v.28 no.11
• /
• pp.1883-1895
• /
• 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
• /
• v.42 no.1
• /
• pp.91-97
• /
• 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
• /
• 2018.10a
• /
• pp.80-80
• /
• 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.