• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.734-738
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• 1999

Bacterial strain showing the ropy characteristics was isolated from Korean wheat bread. Morphology of the isolate was rod and biochemical test revealed that the isolate was Bacillus subtilis. Growth of rope bacteria was about the same as other Bacillus species and inhibited below pH 5.6. Rope bacteria isolated from Korean wheat bread could not survive under the heat treatment of 10 min at $100^{\circ}C$, but could survive at $90^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.598-603
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• 2000

This study was conducted to enhance the storage stability and the wholesomeness of salted and fermented shrimp manufactured with different salt levels by high hydrostatic pressure sterilization. The effects of high hydrostatic pressure treatment on the putrefactive bacteria in the fermented shrimps were investigated and the sterilization kinetics was analyzed. The initial microbial counts of the fermented shrimp with 8%, 18% salt aged for 6 weeks at $20^{circ}C$ were $1.6{\times}10^3,\;1.4{\times}10^4$ CFU/g for bacteria grown on Vibrio selective media, $9.3{\times}10^3,\;1.7{\times}10^5$ CFU/g for bacteria grown on Staphylococcus selective media, respectively, and null for bacteria grown on Salmonella selective media. The degree of the sterilization increased with the magnitude of the pressure and the treatment time. The fermented shrimp pressurized at 6,500 atm for 10 min had no detectable bacteria grown on Vibrio and Staphylococcus selective media at $10^2$ CFU/g detecting limit. High hydrostatic pressure sterilization could be analyzed by first order reaction kinetics. The $D_P$ values of the bacteria grown on Vibrio selective media of the fermented shrimp at 18% salt were higher than those at 8% salt, while those of the bacteria grown on Staphylococcus selective media showed an inverse trend. The $z_p$ values of 8% salt fermented shrimp were higher than those of 18% salt for both bacteria grown on Vibrio selective media and Staphylococcus selective media. High hydrostatic pressure treatment could be applied for the sterilization of the fermented shrimp, and the optimum high pressure sterilization condition was 10 min treatment at 6,500 atm.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.628-640
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• 2015

Cellulase is the key enzyme in the use of cellulose-based biomaterials. Because of its structure, cellulose is difficult to be degraded by enzymes. In order to utilize cellulose-based biomaterials efficiently, evolutionary wisdom of how to use enzymes accurately and harmoniously in a biological system is needed, such as the cellulose digestive system in animals. In this study, the symbiotic bacteria from snails, Achatina fulica, were identified and their cellulase activity was evaluated. The 16S rRNA sequence analysis of 100 aerobic bacteria showed that they belonged to 9 genus and almost half of the bacteria were Lactococcus spp. Among 100 identified strains, only two Aeromonas sp. strains showed cellulase activity. Aeromonas sp. KMBS020 had both endo-${\beta}$-glucanase and ${\beta}$-glucosidase activities but Aeromonas sp. KMBS018 had ${\beta}$-glucosidase activity only. None of the 100 bacterial colonies had any cellobiohydrolase activity.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1433-1436
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• 2008

Flagellate bacteria such as Escherichia coli or Serratia marcescens possess a remarkable motility system based on a reversible rotary motor. We have employed S. marcescens as microactuators in low Reynolds number fluidic environments to move a larger engineering element around. Microstructures fabricated using conventional microfabrication techniques are blotted on the swarm plate, which leaves a bacterial monolayer on the surface of the microstructure. We have investigated microstructures powered by bacteria to determine how cell orientation on the microstructure surface relates to the swarming patterns as well as how the orientation is affected by the blotting process. This study will help to refine directional control of bacterial transporters by exploiting bacterial sensory mechanisms.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.11a
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• pp.33-36
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• 2007

In this study, an antibiosis of antimicrobial mortar developed to reduce biochemical corrosion of sewage facilities concrete was evaluated. First, artificial acceleration test reflecting similarly biochemical corrosion of mortar was developed. Antimicrobial mortar specimen were experimented in this test and antibiosis of it was evaluated by SEM and EDX. As a results of the study, sulfur-oxidizing bacteria on the plain specimen were survived for 20 weeks in this test. But sulfur-oxidizing bacteria on antimicrobial specimen were survived less than the plain, and sulfur-oxidizing bacteria were externally distorted and destroyed. So the antibiosis of an antimicrobial mortar was verified by it.

• Journal of Environmental Science International
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• v.16 no.11
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• pp.1295-1300
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• 2007

The antibacterial effects of anodic electrolyzed water against various bacteria were studied in this investigation. Complete inactivation of Gram-positive and Gram-negative bacteria occurred within 15 s after exposure to anodic electrolyzed water. Moreover, 1/2, 1/5 and 1/10 diluted anodic electrolyzed water by adding deionized water showed strong antibacterial effects. However, the inhibitory effect of anodic electrolyzed water on the anaerobe of Propionibacterium acnes was much weaker than that on the aerobes, including Gram-positive and Gram-negative bacteria. The degraded fragments of E. coli cell were observed upon treating anodic electrolyzed water for 1 min by using scanning electron microscopy.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.73-74
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• 2013

In this study, we examined the properties of the concrete for the adsorption of carbon dioxide by adding in photosynthetic bacteria. As for the experimental plan, we measured slump, carbon dioxide concentration and compressive strength. The findings revealed the non-plastic cement added with photosynthetic bacteria had the greatest flexibility and showed carbon dioxide absorption and condensation delay due to the sugar constituents of photosynthetic bacteria. Giver the progress in the studies on the strength development, it is estimated to be used as CO₂ reduction concrete.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.334.3-334.3
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• 2002

Ginseng(the root of Panax ginseng C.A. Meyer, Araliaceae) has been used for thousands of years as a traditional medicine in Asian countries. The main components of Ginseng are ginsenoside Rb1, Rb2 and Rc. These compounds are transformed by intestinal microflora. The main metabolite of ginsenosides was compoud K (IH-901). The transformed compound K shows an antimetastic or anticarcinogenic effect by blocking tumor invasion or preventing chromosomal aberration and tumorigenesis. Therefore. we isolated and characterzed ginseng saponin-metabolizing bacteria from human intestinal microffora. Among 200 tested intestinal bacteria. we found 78 bacteris to transform glnseng senseng saponins to compound K. These bacteria were seperated into three group: the first group highy produced ginsenside Rd (29) the second grop produced potently ginsenoside F2 (21) and the third produced compound K(28)

• Journal of the Korean institute of surface engineering
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• v.53 no.6
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• pp.285-292
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• 2020

Ancient cultural heritage made up of wood and organic fibers have been easily disintegrated or decomposed by various microorganisms like bacteria and fungi. Here, we demonstrate the effectiveness of an atmospheric pressure plasma jet (APPJ) system to sterilize the microorganisms in tangible cultural heritage. We collected several specimens from the surface of ancient documents and wooden artifacts. Finally, two bacteria and two fungi were prepared and sterilized using the APPJ treatment. The APPJ system is beneficial to its simple apparatus, quick operation time, and cost-effectiveness. Bacteria were almost sterilized within only 1 min treatment using 15 % O2 and applied bias voltage of 100 V. In case of the fungi, sterilization rate reached over 83 % but difficult to reach over 90 % even 10 min treatment. According to the plasma diagnostics using optical emission spectroscopy, it was found that the reactive oxygen species such as OH groups are critical for sterilization of microorganisms. Although further efforts should be performed, we believe that efficient sterilization could be realized by the simple, quick, and portable APPJ treatment system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.2
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• pp.89-93
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• 2005

To manufacture the low-salt anchovy, Engraulis japonicus, sauces with $14\%$ and $17\%$ NaCl, anchovy sauce with $26\%$ NaCl was diluted with sterilized water and then heated at $60^{\circ}C$ for 10 min, 20 min, 30 min, and 40 min. The chemical and microbial changes of the heat-treated low-salt anchovy sauces stored at $25^{\circ}C$ were analyzed at different storage periods. Lactic acid and total nitrogen contents of $14\%$ and $17\%$ NaCl anchovy sauces decreased slightly during storage, but pH, VBN and amino nitrogen contents were almost constant. The amino nitrogen content of $17\%$ NaCl anchovy sauce was higher than that of $14\%$ NaCl anchovy sauce. Total viable cell and lactic acid bacteria were not detected in the anchovy sauce heated at $60^{\circ}C$ for more than 20 min and only proteolytic bacteria was determined less than 10 CFU/mL. The 17% NaCl anchovy sauce heated at $60^{\circ}C$ for 30 min was relatively good for the taste and odor by sensory evaluation.