• Mycobiology
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• v.31 no.2
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• pp.74-80
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• 2003

Isolates of Trichoderma spp. collected from Pleurotus ostreatus and P. eryngii beds, which included loosened substrate compactness and development of green colour, were grouped into three species. The occurrence of different species of Trichoderma was as T. cf. virens(70.8%), T. longibrachiatum(16.7%) and T. harzianum(12.5%). The conidia of Trichoderma spp. were ellipsoidal, obovoid and phialides were bowling pins, lageniform and the length of phialides was $3.5{\sim}10.0{\times}1.3{\sim}3.3{\mu}m$. Phialides of T. cf. virens and T. harzianum were tending clustered, but it was solitary disposition in T. longibrachiatum. T. cf. virens was characterized by predominantly effuse conidiation, sparingly branched, and fertile to the apex and it was penicillate type. RAPD analysis could detect variability amongst three different species of Trichoderma using two newly designed URP-primers. However, intra-specific variation could not be detected in all the isolates except for rDNA sequence data classified Trichoderma isolates into three distinct groups representing three species. The profiles of rDNA sequences of isolates representing a species showed high similarity in T. cf. virens and T. harzianum. However, there was a variation in rDNA sequences of isolates representing T. longibrachiatum. The results of present study reveals that molecular techniques of RAPD and rDNA sequencing can greatly aid in classification based on morphology and precise identification of fast evolving species of Trichoderma.

• Restorative Dentistry and Endodontics
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• v.45 no.1
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• pp.6.1-6.8
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• 2020

Objectives: This study investigated the effects of a hydrofluoric acid (HA; solution of hydrogen fluoride [HF] in water)-based smart etching (SE) solution at an elevated temperature on yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics in terms of bond strength and morphological changes. Materials and Methods: Eighty sintered Y-TZP specimens were prepared for shear bond strength (SBS) testing. The bonding surface of the Y-TZP specimens was treated with 37% phosphoric acid etching at 20℃-25℃, 4% HA etching at 20℃-25℃, or HA-based SE at 70℃-80℃. In all groups, zirconia primers were applied to the bonding surface of Y-TZP. For each group, 2 types of resin cement (with or without methacryloyloxydecyl dihydrogen phosphate [MDP]) were used. SBS testing was performed. Topographic changes of the etched Y-TZP surface were analyzed using scanning electron microscopy and atomic force microscopy. The results were analyzed and compared using 2-way analysis of variance. Results: Regardless of the type of resin cement, the highest bond strength was measured in the SE group, with significant differences compared to the other groups (p < 0.05). In all groups, MDP-containing resin cement yielded significantly higher bond strength values than MDP-free resin cement (p < 0.05). It was also shown that the Y-TZP surface was etched by the SE solution, causing a large change in the surface topography. Conclusions: Bond strength significantly improved when a heated HA-based SE solution was applied to the Y-TZP surface, and the etched Y-TZP surface was more irregular and had higher surface roughness.

• Restorative Dentistry and Endodontics
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• v.24 no.3
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• pp.447-452
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• 1999

The role of bacteria in root canals and periapical infections is well known and established. In these bacteria, black-pigmented bacteria(BPH) play important role in endodontic infection. BPB are Gram negative anaerobic rods which are closely related 50 clinical symptoms such as pain, percussion, tenderness, foul odor, etc. In America and Europe, many studies on BPB have been done and are continued. But, relatively few studies have been done in Korea, especially its prevalence in Korean population is not yet studied. The purpose of this study is to establish prevalence of BPB in infected root canals and periapical abscesses in Korean people. Microbial samples were collected from the root canals of 34 intact tooth with periapical rarefactions of endodontic origin and 3 periapical abscesses. All samples were incubated in an anaerobic chamber(Coy, Model No. 77. Ann Arbor, Michigan, USA.). Identification of In microorganism was based on its growth in the anaerobic chamber, colonial pigmentation, colonial morphology, Gram stain, and Rapid ID32A(BioMericux SA/69280 Marcy-l'Etoile/France) results. In addition, the polyme ase chain reaction using specific primers for 16S rRNA genes were used differentiate Prevotella nigrescens for Prevotella intermedia. The results were as follows : 1. In this study, thirteen (35%) of thirty seven samples were positive for the growth of BPB. In thirteen samples, sixteen strains of BPR were found. 2. The most frequently identified BPB in root canals and abscesses in Korean were P. nigrescens 5/37(14%) and P. intermedia 5/37(14%). Porphyromonas gingivalis 3/37(8%), Porphyromonas endodontalis 2/37(5%) and Prevotella loecheii 1/37(3%) were also found. 3. In this study, no significant differences were found between the prevalence of BPB in Korean and that of American and European.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.287-296
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• 2007

A Lactobacillus paraplantarum strain producing a bacteriocin was isolated from kimchi using the spot-on-the lawn method and named L. paraplantarum C7 [15]. The bacteriocin, paraplantaricin C7, was found to inhibit certain Lactobacillus strains, including L. plantarum, L. pentosus, and L. delbrueckii subsp. lactis. It also inhibited Enterococcus faecalis, yet did not inhibit most of the other LAB (lactic acid bacteria) tested. The maximum level of paraplantaricin C7 activity was observed under the culture conditions of $25^{\circ}C$ and a constant pH of 4.5. Paraplantaricin C7 retained 90% of its activity after 10 min of treatment at $100^{\circ}C$ and remained stable within a pH range of 2-8. Based on a culture supernatant, paraplantaricin C7 was purified by DEAE-Sephacel column chromatography and $C_{18}$ reverse-phase HPLC. SDS-PAGE and activity staining were then conducted using the purified paraplantaricin C7, and its molecular mass determined to be about 3,800 Da. The 28 N-terminal amino acids from the purified paraplantaricin C7 were determined, and the structural gene encoding paraplantaricin C7, ppnC7, was cloned by PCR using degenerate primers based on the N-terminal amino acid sequence. The nucleotide sequences for ppnC7 and other neighboring orfs exhibited a limited homology to the previously reported plantaricin operon genes. Paraplantaricin C7 is a novel type II bacteriocin containing a double glycine leader sequence.

• Restorative Dentistry and Endodontics
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• v.32 no.3
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• pp.236-247
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• 2007

The purpose of this study was to evaluate the effects of cyanate methacylate on the shear bond strengths to bovine dentin surfaces as a dentin primers. Seven experimental adhesives were made with different mass fraction of Isocyanatoetylme-thacrylate (IEM), 40wt% HEMA (Wako Pure Chemical Industries Osaka, Japan), 0.6% camphoroquinone, 0.4% amine and ethanol as balance dentin bonding agents (0, 2, 4, 6, 8, 10, 12%) were made and applied on the surface of bovine dentin specimens of 7 experimental groups. Shear bond strengths were measured using a universal testing machine (Instro 4466). To identify the ratio and modes of cohesive failures, microscopic examinationn was performed. The ultra-structure of resin tags were observed under scanning electron microscope. The results were as follows ; 1) A higher shear bond strengths (33.62 MPa) in group 8% of Cyanate methacrylate to dentin were found, but there were no statistically significancy between Groups (p > 0.05). 2) The higher ratio of cohesive failures mode in group 2, 6, an 10% could be seen than that in any other groups. 3) A shorter resin tags were observed in all experimental groups. This could be resulted that the preventing from the cyanate methacrylate penetrate into dentin owing to reacting it with dentin collagen. Therefore the resin tags were shorter in lengths. Whether the higher bonding strengths of dentin bonding agents can be affected was not been assured with statistic results. The results indicated that the relation between tensile strengths of the dentin adhesives to bovine dentin and resin tags formed into the dentin could not affected. The main reason of increasing the shear bond strength to bovine dentin in experimental groups could not be assured.

• Plant Biotechnology Reports
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• v.2 no.3
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• pp.191-198
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• 2008

Germplasm characterization and evolutionary process in viable populations are important links between the conservation and utilization of plant genetic resources. Here, an investigation is made, based on molecular and biochemical techniques for assessing and exploiting the genetic variability in germplasm characterization of taro, which would be useful in plant breeding and ex situ conservation of taro plant genetic resources. Geographical differentiation and phylogenetic relationships of Indian taro, Colocasia esculenta (L.) Schott, were analyzed by random amplified polymorphic DNA (RAPD) and isozyme of seven enzyme systems with specific reference to the Muktakeshi accession, which has been to be proved resistant to taro leaf blight caused by P. colocasiae. The significant differentiations in Indian taro cultivars were clearly demonstrated by RAPD and isozyme analysis. RAPD markers showed higher values for genetic differentiation among taro cultivars and lower coefficient of variation than those obtained from isozymes. Genetic differentiation was evident in the taro accessions collected from different regions of India. It appears that when taro cultivation was introduced to a new area, only a small fraction of genetic variability in heterogeneous taro populations was transferred, possibly causing random differentiation among locally adapted taro populations. The selected primers will be useful for future genetic analysis and provide taro breeders with a genetic basis for selection of parents for crop improvement. Polymorphic markers identified in the DNA fingerprinting study will be useful for screening a segregating population, which is being generated in our laboratory aimed at developing a taro genetic linkage map.

• Mycobiology
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• v.41 no.4
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• pp.252-255
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• 2013

Fungal pathogens have caused severe damage to the commercial production of Pleurotus eryngii, the king oyster mushroom, by reducing production yield, causing deterioration of commercial value, and shortening shelf-life. Four strains of pathogenic fungi, including Trichoderma koningiopsis DC3, Phomopsis sp. MP4, Mucor circinelloides MP5, and Cladosporium bruhnei MP6, were isolated from the bottle culture of diseased P. eryngii. A species-specific primer set was designed for each fungus from the ITS1-5.8S rDNA-ITS2 sequences. PCR using the ITS primer set yielded a unique DNA band for each fungus without any cross-reaction, proving the validity of our method in detection of mushroom fungal pathogens.

• Animal cells and systems
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• v.9 no.4
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• pp.205-209
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• 2005

A rapid, simple and efficient method to extract RNA from the adult polyps of a soft coral, marine cnidarian, Scleronephthya gracillimum $(K\ddot{u}kenthal)$; was developed in this study. The highest yield and purity of RNA was obtained with the lysis solution containing 35 mM EDTA, 0.7 M LiCl, 7.0% SDS, and 200 mM Tris-Cl (pH 9.0). Approximately $40{\mu}g$ of total RNA was extracted from 200 mg of liquid nitrogen-pulverized polyp tissue. The ratio of absorbance at 260 nm and 280 nm ranged from 1.8 to 2.0. The results of the reverse transcription polymerase chain reaction (RTPCR) with ${\beta}-actin$ gene specific primers and Northern blot analysis using the same gene probe revealed that the RNA extracted by our method had high quality, and was sufficient for subsequent molecular biological analyses. This method was effective for RNA extraction from other soft coral species which belong to the genus Dendronephthya.

• Journal of Genetic Medicine
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• v.3 no.1
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• pp.11-13
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• 1999

Recently it was reported that Insertion/Deletion polymorphism in the gene coding for Angiotensin-Converting Enzyme (ACE) is associated with human capacity for physical performance. This study was performed to genotyping of the ACE gene to determine the correlation between elite endurance performance and ACE I/D gene polymorphism. DNA sample was obtained from peripheral blood, hair roots and mouth epithelial cell in 739 general population and 200 elite athletic performance students. The ACE gene was amplified by polymerase chain reaction (PCR) using allele specific oligonucleotide primers. 155, 525 bp and 237 bp PCR products indicating the presence of insertion(I) and deletion(D) alleles, respectively, were clearly resolved after electrophoresis on a 2% agarose gel with ethidium bromide. Of the 200 elite athletic performance population subjects, 68(34%) showed ACE genotype 11,100(50%) genotype ID and 32(16%) genotype DD. Of the 739 general population subjects, 259(35.1%) showed ACE genotype 11,363(49.1%) genotype ID and 117(15.8%) genotype DD. Therefore ACE I/D gene polymorphism was not associated with human capacity for physical performance.(p>0.05)

• Korean Journal of Medicinal Crop Science
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• v.14 no.3
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• pp.125-129
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• 2006

Two herbal medicines of the Polygonatum genus, namely Polygonati Rhizoma and Polygonati Odorati Rhizoma, are difficult to distinguish from each other through exterior morphologic aspects. Furthermore, because the standard components for physiochemical distinction have not yet been standardized, the identification of these medicines through botanic taxology is based on genetic methods of random amplified microsatellite polymorphism (RAMP). For the RAMP evaluation, we used five sets of UBC microsatellite primers 811, 818, 834, 836, 842 and random primer M1. Although no specific band that could clearly distinguish Polygonati Rhizoma from Polygonati Odorati Rhizoma was found, 11 Polygonatum plants could be divided into two groups by this method. P. sibiricum and P. stenophyllum were classified to group I and the others were to group II. As P. sibiricum and P. stenophyllum were very similar in genetic and morphologic perspective, the results suggest that P. stenophyllum belongs to the Polygonati Rhizoma family.