• Journal of Mushroom
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• v.10 no.2
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• pp.93-99
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• 2012

This study was carried to identify a correct species and asses genetic diversity within the same species of Grifola spp. preserved in Division of applied Microbiology. Contaminated isolates showed different growth rates, morphology and color of hyphae. We have reconstructed the phylogenetic tree of a select group of Grifola spp. using nucleotide sequences of the internal transcribed spacer region(ITS) region. The phylogenetic tree was constructed by using the neighbor-joining method. PELF primers of 20-mer were used to assess genetic diversity of preserved isolates. Sequence analysis showed that four strains were identified completely different nomenclature. According to the analysis of ITS sequences, the genus Grifola clustered into one group, most of which correlated with species-groups identified by RAPD method. Eight isolates included strain GM01 showed high similarity with Grifola frondosa. All isolates were collected in the Japan(GM01, GM02, GM03) was identified as Grifola frondosa and isolates of the China(GM05, GM06, GM08) was identified as Bjerkandera fumosa, Grifola frondosa and Dichomitus squalens, respectively. RAPD analysis of genetic polymorphisms of genus Grifola showed a very different band patterns on the isolat. As the result of RAPD and ITS region sequences analysis for preserved isolates, it seems likely that 4 isolates of Grifola spp. may be need to reclassify or eliminate from preserved catalogue.

• Journal of Life Science
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• v.28 no.3
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• pp.361-368
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• 2018

This study investigated the diversity of communities of intestinal microorganisms, separated from the intestinal organs of Red tilefish (Branchiostegus japonicas), collected on the Jeju Coast. First, in the isolation of 1.5% BHIA, MA, TSA and R2A Agar on the medium, there were most colonies in 1.5% BHIA. The results of aerobic culture and anaerobic culture were $1.7{\times}10^6CFU/g^{-1}$ and $1.1{\times}10^5cfu/g^{-1}$, respectively, on average, and 147 pure colonies were separated in total. In 16S rDNA sequencing, there were 58 genera and 74 species, showing 95-100% similarity with the basic strain. They were divided broadly into 5 phyla, and as the main phyletic group, Proteobacteria phylum comprised 50% with 9 families, 35 genera and 35 species of Moraxellaceae, Rhodobacteraceae, Shewanellae, Halomondaceae, Enterobacteriaceae, Vibrionaceae, Hahellaceae, Pseudomonadaceae, and Erythrobacteraceae, with the highest index of dominance. Actinobacteria phylum comprised 24% with 8 families, 11 genera and 17 species of Microbacteriaceae, Intrasporangiaceae, Dietziaceae, Dermabacteraceae, Dermacoccaceae, Nocardiodaceae, Brevibacteriaceae and Propionobacteriacea; Firmicutes phylum, 16% with 6 families, 8 genera and 17 species of Bacillaceae, Staphylcoccaceae, Planococcaceae, Streptococcaceae, Paenibacillaceae and Clostridiaceae; Bacteroidetes phylum, 6% with 2 families, 3 genera and 4 species of Cyclobacteriaceae and Flavobacteriaceae; and Deinococcus-Thermus phylum, 4% with 1 family, 1 genus and 1 species of Deinococcaceae.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1286-1298
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• 2005

The genus Paenibacillus is a new group of bacilli separated from the genus Bacillus, and most of species have been isolated from soil. In the present study, we collected 450 spore-forming bacilli from the roots of winter crops, such as barley, wheat, onion, green onion, and Chinese cabbage, which were cultivated in the southern part of Korea. Among these 450 isolates, 104 Paenibacillus-like isolates were selected, based on their colony shape, odor, color, and endospore morphology, and 41 isolates were then finally identified as Paenibacillus spp. by 16S rDNA sequencing. Among the 41 Paenibacillus isolates, 23 were classified as P. polymyxa, a type species of the genus Paenibacillus, based on comparison of the 16S rDNA sequences with those of 32 type strains of the genus Paenibacillus from the GenBank database. Thirty-five isolates among the 41 Paenibacillus isolates exhibited antagonistic activity towards plant fungal and bacterial pathogens, whereas 24 isolates had a significant growth-enhancing effect on cucumber seedlings, when applied to the seeds. An assessment of the root-colonization capacity under gnotobiotic conditions revealed that all 41 isolates were able to colonize cucumber roots without any significant difference. Twenty-one of the Paenibacillus isolates were shown to contain the nifH gene, which is an indicator of $N_{2}$ fixation. However, the other 20 isolates, including the reference strain E681, did not incorporate the nifH gene. To investigate the diversity of the isolates, a BOX-PCR was performed, and the resulting electrophoresis patterns allowed the 41 Paenibacillus isolates to be divided into three groups (Groups A, B, and C). One group included Paenibacillus strains isolated mainly from barley or wheat, whereas the other two groups contained strains isolated from diverse plant samples. Accordingly, the present results showed that the Paenibacillus isolates collected from the rhizosphere of winter crops were diverse in their biological and genetic characteristics, and they are good candidates for further application studies.

• Journal of Mushroom
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• v.9 no.1
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• pp.27-33
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• 2011

This study was carried to identify a correct species and asses genetic diversity within the same species of Trametes spp. preserved in Division of applied Microbiology The morphological and cultural characteristics of preserved strains were observed through microscope and investigated on PDA, respectively. Contaminated isolates showed different growth rates, morphology and color of hyphae. We have reconstructed the phylogenetic tree of a select group of Trametes spp. using nucleotide sequences of the internal transcribed spacer region(ITS) region. The phylogenetic tree was constructed by using the neighbor-joining method. PELF primers of 20-mer were used to assess genetic diversity of preserved isolates. Sequence analysis showed that five strains were different species and six strains were identified completely different nomenclature. According to the analysis of ITS sequences, the genus Trametes clustered into four distinct group, most of which correlated with species-groups identified by RAPD method. Seven isolates included TM 01 strain showed high similarity with Trametes versicolr, TM 07 and TM 10 high similarity with Trametes gibbosa, and TM 05 high similarity with Trametes elegans. But isolates collected in the United States was identified as T. junipericola. T. gibbosa and T. versicolor by RAPD analysis of genetic polymorphisms showed a very different band patterns and these strains showed different band patterns on areas. As the result of RAPD and ITS region sequences analysis for preserved isolates, it seems likely that 11 isolates of Trametes spp. may be need to reclassify or eliminate from preserved catalogue.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.2
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• pp.76-88
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• 2004

The purpose of this study was to investigate the distribution of Enterococci isolated from clinical specimens, and identify the aspect of antibiotic susceptibility and analyze the genetic difference by executing Rep-PCR over the strains resistant to aminoglycoside-typed antibiotics. From an assortment of the clinical specimens, 100 strains were isolated. The collection consisted of 49 strains of E. faecalis, 34 strains of E. faecium, 9 strains of E. avium, 4 strains of E. gallinarum, 3 strains of E. casseliflavus, and 1 strain of E. hirae. Ninety five were isolated from inpatients, and five strains were isolated from outpatient. Most of the E. faecalis and E. faecium were originated from urine, pus, and sputum. Most Enterococci showed 80% resistance to the cephalosprin-typed antibiotics. E. faecium showed the high resistance to all the antibiotic substances. One tenths of Enterococci showed the resistance to vancomycin. And also, most Enterococci showed the high resistance to amikacin and gentamicin as aminoglycoside-typed antibiotics. Genetic diversity of the resistant strains to aminoglycoside estimated using Rep-PCR was not significanty different.

• Journal of Life Science
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• v.23 no.1
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• pp.95-101
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• 2013

In this study, plant samples of five species were collected from the Dokdo islands in South Korea. Plant samples such as Asparagus schoberioides, Corydalis platycarpa, Festuca rubra, Sedum oryzifolium, and Setaria viridis were collected from the Dongdo and Seodo. Endophytic fungal strains were isolated from the roots of five plants from the Dokdo islands. Thirty-three fungal strains were isolated from these native plants. All the endophytic fungi were analyzed by internal transcribed spacer (ITS) sequencing (ITS containing ITS1, 5.8s, and the ITS2 region). Waito-c rice seedlings were treated with fungal culture filtrates to test their plant growth-promoting activity. A bioassay of the D-So-1-1 fungal strain isolated from S. oryzifolium confirmed that it has the highest plant growth-promoting activity. All the endophytic fungi belong to four orders: Eurotiales (86%), Capnodiales (3%), Hypocreales (4%), and Incertae sedis (7%). The endophytic fungi were classified as Ascomycota, which contained Aspergillus (12%), Cladosporium (3%), Eurotium (3%), Fusarium (18%), Microsphaeropsis (6%), and Penicillium (58%) at the genus level.

• Journal of Microbiology and Biotechnology
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• v.34 no.5
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• pp.1146-1153
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• 2024

The increasing economic losses associated with growth retardation caused by Enterocytozoon hepatopenaei (EHP), a microsporidian parasite infecting penaeid shrimp, require effective monitoring. The internal transcribed spacer (ITS)-1 region, the non-coding region of ribosomal clusters between 18S and 5.8S rRNA genes, is widely used in phylogenetic studies due to its high variability. In this study, the ITS-1 region sequence (~600-bp) of EHP was first identified, and primers for a polymerase chain reaction (PCR) assay targeting that sequence were designed. A newly developed nested-PCR method successfully detected the EHP in various shrimp (Penaeus vannamei and P. monodon) and related samples, including water and feces collected from Indonesia, Thailand, South Korea, India, and Malaysia. The primers did not cross-react with other hosts and pathogens, and this PCR assay is more sensitive than existing PCR detection methods targeting the small subunit ribosomal RNA (SSU rRNA) and spore wall protein (SWP) genes. Phylogenetic analysis based on the ITS-1 sequences indicated that the Indonesian strain was distinct (86.2% nucleotide sequence identity) from other strains collected from Thailand and South Korea, and also showed the internal diversity among Thailand (N = 7, divided into four branches) and South Korean (N = 5, divided into two branches) samples. The results revealed the ability of the ITS-1 region to determine the genetic diversity of EHP from different geographical origins.

• Journal of Species Research
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• v.6 no.2
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• pp.101-118
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• 2017

In an investigation of indigenous prokaryotic species in Korea, a total of 57 bacterial strains assigned to the classes Betaproteobacteria and Gammaproteobacteria were isolated from diverse environments. Samples were collected from fresh water, natural caves, soil, paddy fields, lakes, sea water, jeotgal (fermented seafood), salt flats, soil from abandoned mines, plant roots, digestive organs of both Japanese crested ibis (Nipponia nippon) and Burmese python (Python molurus bivittatus) and tidal flats. From the high 16S rRNA gene sequence similarity (>98.7%) and formation of robust phylogenetic clades with closely related species, it was determined that each strain belonged to an independent and predefined bacterial species within either the Betaproteobacteria or Gammaproteobacteria. There is no official report or publication that describes these 57 proteobacterial species in Korea. Overall, in the class Betaproteobacteria there were 16 species in 12 genera of 4 families in the order Burkholderiales and two species in two genera of one family in the order Neisseriales. Within the class Gammaproteobacteia, there were five species in four genera of four families in the order Alteromonadales, 12 species in 11 genera of one family in the order Enterobacteriales, four species in four genera of three families in the order Oceanospirillales, 11 species in four genera of two families in the order Pseudomonadales, two species in the order Vibrionales and five species in five genera of one family in the order Xanthomonadales. Gram reaction, colony and cell morphology, basic biochemical characteristics, isolation source and strain IDs are described in the species description section.

• Journal of the Korea Concrete Institute
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• v.28 no.2
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• pp.167-176
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• 2016

Shear friction strength model of concrete was proposed to explain the direct friction mechanism at the concrete interfaces intersecting two structural elements. The model was derived from a mechanism analysis based on the upper-bound theorem of concrete plasticity considering the effect of transverse reinforcement and applied axial loads on the shear strength at concrete interfaces. Concrete was modelled as a rigid-perfectly plastic material obeying modified Coulomb failure criteria. To allow the influence of concrete type and maximum aggregate size on the effectiveness strength of concrete, the stress-strain models proposed by Yang et al. and Hordijk were employed in compression and tension, respectively. From the conversion of these stress-strain models into rigidly perfect materials, the effectiveness factor for compression, ratio of effective tensile strength to compressive strength and angle of concrete friction were then mathematically generalized. The proposed shear friction strength model was compared with 91 push-off specimens compiled from the available literature. Unlike the existing equations or code equations, the proposed model possessed an application of diversity against various parameters. As a result, the mean and standard deviation of the ratios between experiments and predictions using the present model are 0.95 and 0.15, respectively, indicating a better accuracy and less variation than the other equations, regardless of concrete type, the amount of transverse reinforcement, and the magnitude of applied axial stresses.

• Journal of Mushroom
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• v.16 no.3
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• pp.198-202
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• 2018

'Yong-A' was bred by Jeollanamdo Agricultural Research and Extension Services in 2015. It was primarily selected through monospore crossing between JNM21008 and JNM21013 in 2009. The strain is named as JNM-Mi-194 and 'Yong-A', showing major characteristics with good production yield. The cultivation characteristics, yield potential, and fruiting body characteristics of 'Yong-A' are as follows; The wrinkle of the fruiting body was of branching type its shape was wave type. MCM, YM, Malt, and PDA media were suitable for growth of this cultivar. The number of effective stipes was 13 ea/0.9 kg. The minor axis of pileus was 5 cm and the major axis was 9 cm. The yield was 291 g per plastic bag (0.9 kg). Yong-A required 60 days for mycelial running at $20^{\circ}C$. The growth and primordial period required 24 days, which was shorter than that of JNM-Mi-21002 (the conventional cultivar). Somatic incompatibility was observed between parental lines and Yong-A. Analysis of genetic diversity in the new variety 'Yong-A' showed a different profile compared to that of the parent strain when Random Amplified Polymorphic DNA primers were used.