• Journal of Life Science
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• v.18 no.11
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• pp.1606-1611
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• 2008

Outer membrane proteins (OMPs) expressed in the Gram negative bacteria such as Salmonella play multiple functions including material transports, adhesive factors and reception of external signals. This study has been focused on an OmpW protein known as a protein required to form a hydrophobic porin in outer membrane. We have constructed a S. typhimurium CK10 mutant deleting an ompW gene on chromosome. The CK10 strain was more tolerant to SDS than the wild-type strain did. As increase of salt concentration in the culture media, significantly decreased amount of OmpW protein in cells were detected. The maximum OmpW protein was expressed in the absence of salt supplement. However, the growth of CK10 strain was indistinguishable compared to that of the wild-type strain at the variable osmotic conditions. The biological role of differential OmpW expression in response to osmotic conditions remains to be investigated.

• Korean Journal of Microbiology
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• v.38 no.1
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• pp.26-30
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• 2002

A ubiquitous bacterium,Effects of Lead, Copper and Cadmium on Pseudomonas cepacia KH410 Isolated from Freshwater Plant Root was isolated from freshwater plant root and interactions of lead, copper and cadmium with this strain was studied. Mass production of dry cell weight 2.72 g-DCW/ι-medium was obtained by cultivation in a nutrient medium containing 1% yeast extract, 1% soytone and 0.5% NaCl, pH 7.0, at temperature of 28℃ for 24 hrs under aeration. The mass of dry cell produced after exposure with 100 mg/ι of heavy metal was 1.98 g/ι for lead, 1.58 g/ι for copper and 0.20 g/ι for cadmium, respectively. The minimal inhibitory concentrations (MIC) for each heavy metal was 1.3 mM for lead,0.8 mM for copper and 0.4 mM fur cadmium, respectively. Cell aggregation occurred by each heavy metal exposure was observed from 1 day to 4 days by an optical microscope. Entrapment, precipitation effects on cell by heavy metals between 10 min and two hours were examined by an electron microscopy. Cadmium appeared to be the most toxic on cells and the order of toxicity was cadmium>copper>lead.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.452-459
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• 2015

The effects of aronia powder on the rheological and sensory characteristics of Sulgidduk were investigated. The moisture content of Sulgidduk ranged from 40.86 to 44.40%; however, addition of aronia powder to Sulgidduk tended to decrease its moisture content. With regard to the rheological properties, the addition of aronia powder decreased the hardness, springiness, adhesiveness, cohesiveness, chewiness, gumminess, and brittleness of Sulgidduk. Chromaticity determination revealed a decrease in L and b values, while the a value increased with the increasing amounts of aronia powder. Total polyphenol, total flavonoid and total anthocyanin contents increased with the increasing amounts of aronia powder. Antioxidant activity, measured by DPPH and ABTS radical scavenging activities, was significantly higher than that of the control, and increased proportionally with the amount of aronia powder. During 4 day storage, the growth of total aerobic colony and coliform content significantly decreased with increasing levels of aronia powder in Sulgidduk. Sensory evaluation demonstrated the best score in color, taste and overall acceptance when aronia powder was added at 5% of rice powder. These results suggest that 5% aronia powder can be added for the preparation of Sulgidduk.

• Journal of Life Science
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• v.20 no.6
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• pp.861-869
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• 2010

Imitation crab stick samples were made from Alaska pollack with protein recovered from spent laying hens breast meat (C), Alaska pollack with spent laying hens breast recovered protein and cordyceps powder (T1), Alaska pollack with spent laying hens breast recovered protein and silkworm cocoon powder (T2), and Alaska pollack with spent laying hens breast recovered protein and conjugated linoleic acid (CLA) (T3). There were no significant differences in moisture, crude protein and crude fat among the imitation crab samples. pH was significantly higher in T2 and T3 compared with C and T1 after 4 weeks of storage. The values of $L^*$, $a^*$, $b^*$, and W (whiteness) in T3 were found to be more stable during storage and W in T3 was significantly higher than other samples. T3 was significantly lower in hardness, brittleness, gumminess and adhesiveness after 4 weeks of storage. Thiobarbituric acid reactive substance (TBA) values decreased with storage, whereas volatile basic nitron (VBN) values increased with storage periods in all samples. In sensory evaluation, there were no significant differences in color, odor, taste, tenderness, juiciness and overall acceptability among the samples. T3 was significantly lowest in quality among the treated samples.

• Applied Microscopy
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• v.32 no.2
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• pp.163-170
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• 2002

Experimatal maxillary sinusitis was induced in New Zealand white rabbits by blocking the maxillary sinus ostium. The distribution of lectin receptors was explored in the mucosa with induced maxillary sinusitis using colloidal gold label complex with lectin WGA purified from wheat germ (Triticum vulgaris). The lectin WGA gold complex, shown to recognize GlcNac (N-acetylglucosamine) and NeuNAc (N-acetylneuraminic acid) regions, was applied to detect binding sites in Lowicryl HM 20 sections and viewed under the electron microscope. An increased height of the cylindric cells, ciliary loss and hyperplasia of the secretory cells were observed. Examination of normal sinus mucosa labeled with gold-labeled lectins showed the distribution of sialoglycoconjugates to be mainly in the ciliary layer and the granules in the secretory cells. Inflamed mucosa had increased labeling intensity of gold-labeled WGA in the cilia and the secretory granules. These results indicate that lectin WGA receptors are located in the cilia and secretory granules. Specific changes in the lectin binding pattern were apparent in the inflamed mucosa in the experimentally induced acute sinusitis, in comparison with normal mucosa, conceivably as a part of host defense reactions.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.2
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• pp.138-144
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• 2011

Purpose: The purpose of this study was to evaluate the cleansing effect of recently developed alkaline ionized water, e-WASH, on microorganisms of the denture surface. Materials and methods: Removable partial and complete dentures were randomly assigned to the experimental group of 41 dentures, and the control group of 26. The denture was immersed in the e-WASH solution (experimental group), or tap water (control group) for 5 minutes. The plaque was collected from the denture surface before and after immersion, and smeared on the slide glass. Amount and motility of microorganisms were compared according to the morphology and strain of microorganisms, using the phase contrast microscope. Statistical analysis was accomplished with paired t-test and independent t-test at 95% confidence level (P<.05). Results: 1. The amount of cocci, bacilli, filamentous, spiral/comma, and the motility of bacilli, filamentous, and spiral/comma were decreased after denture cleansing with the alkaline ionized water, e-WASH (P<.05). But in the control group, only the amount of cocci showed a significant difference (P<.05), but no difference from the others. There were no differences in other analysis. 2. In the experimental group, the amount of cocci, bacilli, filamentous, spiral/comma, and the motility of bacilli, filamentous, and spiral/comma were smaller and more inactive compared to the control group (P<.05). Conclusion: These results indicated that the alkaline ionized water, e-WASH could effectively reduce the amount and motility of the experimented microorganisms on the denture surface, and that e-WASH could be recommended as an effective denture cleanser.

• Journal of Life Science
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• v.27 no.9
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• pp.1086-1095
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• 2017

There is growing interest in groundwater resources to overcome the loss of surface water resources due to climate change. An understanding of the microbial community of aquifers is essential for monitoring and evaluating groundwater contamination, as well as groundwater management. Most microorganisms that inhabit aquifer ecosystems are attached to sediment particles rather than planktonic, as is the case in groundwater. Since sampling aquifer sediment is not easy, groundwater, which contains planktonic microorganisms, is generally sampled in microbial community research. Although many studies have investigated microbial communities in contaminated aquifers, there are only a few reports of microbial communities in uncontaminated or pristine aquifers, resulting in limited information on aquifer microbial diversity. Such information is needed for groundwater quality improvement. This paper describes the ecology and community structure of groundwater bacteria in uncontaminated aquifers. The diversity and structures of microbial communities in these aquifers were affected by the concentration or distribution of substrates (e.g., minerals, organic matter, etc), in addition to groundwater characteristics and human activities. Most of the microbial communities in these uncontaminated aquifers were dominated by Proteobacteria. Studies of microbial communities in uncontaminated aquifers are important to better understand the biogeochemical processes associated with groundwater quality improvement. In addition, information on the microbial communities of aquifers can be used as a basis to monitor changes in community structure due to contamination.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.437-441
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• 2005

This study was investigated to compare the suppression of Meloidogyne arenaria by different treatments of Pasteuria penetrans which is known for biological control agent against Meloidogyne spp.. In order to select proper number of P. penetrans showing good suppression effect, P. penetrans were mixed with M, arenaria for attachment using three different concentration such as $3{\times}10^4$, $3{\times}10^5$ and $3{\times}10^6$ endospores/5 g medium, followed by treating them onto the roots of tomato. After 14 weeks incubation, P. penetrans at $3{\times}10^6$ endospores showed highest activity against the formation of gall caused by M, arenaria. At a dose of $3{\times}10^5$ endospores/5 g medium, P. penetrans was treated into soil either mixing with soil or spray onto soil surface for comparing of suppressive efficacy. When the antagonistic bacterium was treated by the former method, it suppressed more effectively Using P. penetrans at $3{\times}10^6$ endospores and mixing with soil method, suppression was compared among P. penetrans, $PASTORIA^{(R)}$(Japan) and $Fosthiazate^{(R)}$(Korea). P. penetrans was more potent than $PASTORIA^{(R)}$(Japan) and as similar as $Fosthiazate^{(R)}$(Korea). Therefore, these results suggested that P. penetrans can be used for controling of M. arenaria as biological control agent. Furthermore, thess results can be provided to develop environmentally-friendly nematicide.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.103-117
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• 2017

The aim of this study was to evaluate the effect of green tea extract on probiotic potential, physico-chemical and functional properties of yogurt fermented with Lactobacillus acidophilus D11 or Lactobacillus fermentum D37 strains isolated from Doenjang. Probiotic activities such as the resistance to artificial digestive juices and the ability to adhere to epithelial cells were slightly higher in yogurt supplemented with green tea extract than in plain yogurt, which may be attributed to the increase in the number of lactic acid bacteria (LAB) by green tea extract supplementation. Furthermore, the microbiological and physico-chemical properties such as the number of LAB, organic acid production and viscosity were significantly (P<0.05) increased in yogurt added green tea extract compared to plain yogurt fermented with L. acidophilus D11. However, the green tea extract did not significantly (P>0.05) affect these properties of yogurt fermented with L. fermentum D37 strain. Meanwhile, the antibacterial activities against Escherichia coli O157 ATCC 43889, Salmonella enteritidis ATCC 13076, and Salmonella typhimurium KCTC 2514 and antioxidant activities including total phenol content, radical scavenging ability, and ferric-reducing antioxidant power were significantly higher in plain yogurt fermented with L. fermentum D37 than with L. acidophilus D11. The antibacterial and antioxidant activities of the yogurt were significantly (P<0.05) increased in proportion to the concentration of green tea extract added to plain yogurt. Consequently, green tea yogurt fermented with L. acidophilus D11 or L. fermentum D37 was considered to be a useful functional food that can inhibit the growth of pathogenic bacteria and scavenge the free radicals from the body cells.

• Journal of fish pathology
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• v.12 no.1
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• pp.7-15
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• 1999

In order to investigate the immune response induced by supplementation of herb medical stuff in diet on the nile tilapia. Oreochromis niloticus, experiments were performed with feeding of four different experimental diets supplemented with 2% ginseng. Panax ginseng, 3% Kugija. Lycium chinense, 3% Hasuo, Polygonum multiflorum, 2% Omija, Schizandra chinensis, respectively, for 84 days. The non-specific immune responses changed during the feeding period were investigated at 2, 4, 6, 8, 10, 12 weeks in each group. Average body weight of the nile tilapia with supplemented diets was heavier than control group. The fish fed on diet supplemented with 3% Kugija showed the better growth than the other tested groups. Complement activity such as complete hemolytic activity ($CH_{50}$) and bactericidal activity against Escherichia coli tended to be increased by the supplementation of herb medical stuff. The lysozyme activity of serum and adherent phagocyte activity showed higher in the fish fec on diet supplemented with 3% kugija than the other tested groups. In respect to the RPS against experimental Edwardsiella tarda infection, all of the group fed on the herb medical stuff in diet appeared higher response compared with control group. From these results, herb medical stuff (Panax ginseng, Lycium chinense. Polygonum multiflorum, Schizandra chinensis) might be used a additives of diet for the increasing of non-specific immune response or resistance against bacterial fish diseases.