• Journal of Korean Society of Archives and Records Management
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• v.1 no.1
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• pp.231-243
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• 2001

The sterilization method of records by fumigation using mixed gas of methyl bromide(MB) and ethylene oxide(ETO) has been generally used as a way to protect biological deterioration by microorganisms and insects. In this study, we confirmed sterilization effect of MB and ETO [86 : 14(Vol.%)] on and analyzed toxicity on microorganisms isolated from records. To analyze sterilization effect of fumigation on microorganisms and insect, we have fumigated microorganisms and insect with a various amounts mixed gas of MB and ETO, and various exposure time. Insect was sterilized at all experimental conditions. In microorganisms, sterilization effect was detected only when the mixed gas was treated at $120g/m^3$ concentration for at least 24 hrs. To test the possibility of isolated microorganisms as a threat to human health, it was investigated that toxicity test using yeast, radish and cancer cells on microorganisms. Only Aspergillus oryzae had an inhibition effect on growth of yeast. radish and cancer cells, respectively. These results demonstrate that sterilization effect can occur at low concentrations of the mixed gas on insect but requires higher concentrations of the mixed gas on microorganisms. In addition to, it is suspected that the possibility of the microorganism as a threat to human health is little.

• The Korean Journal of Food And Nutrition
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• v.31 no.2
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• pp.308-312
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• 2018

Even though chlorine dioxide ($ClO_2$) is utilized in a pre-treatment due to its effective sterilizing activity for microorganisms and its safety for food, it has a limitation in maintaining freshness of the food product. In this study, a low-concentration $ClO_2$ gas was produced in a packaging form of air-permeable gel pack so that it could be released continuously over several days. The amount of $ClO_2$ gas emission and microbial inactivation effect against foodborne pathogens were measured during the release of $ClO_2$ gas. As a result of measuring the change of color in order to confirm whether the chlorine dioxide gas was eluted in the form of a sustained release, the yellowness was significantly higher at higher gel pack concentration and higher value during storage periods. The slow-released $ClO_2$ gel-pack showed clear inactivation effect against Escherichia coli and Staphylococcus aureus with 99.9% inactivation efficiency. As a result of measuring the sterilization effect of Listeria monocytogenes by the concentration of chlorine dioxide gas, the sterilization effect was increased as the concentration was increased. Therefore, the slow-released $ClO_2$ gel-pack is feasible to apply for industry usages.

• 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 Microbiology
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• v.5 no.1
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• pp.7-14
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• 1967

The synergistic actions of certain antimetabolic agents for Saccharomyces cerevisiae and Lactobacillus plantarum on radiation sterilization have been studied. The used chemical agents are sorbic acid, vitamin-$K_3$, dehydroacetic acid, p-oxybutyl benzoate and nitrofurazone, those are the permitted as food preservatives. Experimental results are as following, 1) Survival fraction of yeast which was gamma-irradiated and influenced by sorbic acid or vitamin $K_3$ is much reduced than that of only irradiated respectively. 2) It seems like that the used chemicals acts synergistically on radiation sterilization. Sodium-dehydroacetate and p-oxybutyl benzoate are proved to be also synergistic but weakly. 3) Survival fraction of Lact. plantarum which was gamma-irradiated and influenced by sorbic acid, dehydroacetic acid or nitrofurazone respectively much reduced than that of only irradiated group, it can be estimated as synergistic action of chemical affected on radiation sterilization. 4) It was found that nutrient componets can affect radiation sterilization of microorganisms protectively.

• The Korean Journal of Food And Nutrition
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• v.25 no.1
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• pp.69-76
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• 2012

Intense pulsed light(IPL) has been highlighted as an innovative nonthermal sterilization technology that can kill spoilage or pathogenic microorganisms by using short-duration pulses of intense broad-spectrum electromagnetic radiation. This paper examines the inactivation effects of IPL on Listeria monocytogenes, Escherichia coli O157:H7, and Pseudomonas aeruginosa inoculated on seafood products such as salmon, flatfish, and shrimps and evaluates the possibility of extending the shelf-life of seafood products. The results indicate that the inactivation of microorganisms increased with an increase in IPL energy density($J/cm^2$) and a decrease in the distance between the sample surface and the lamp. In addition, temperature increases on the fish fillets during the treatments were well controlled within the range of 5.7~$9.8^{\circ}C$. The IPL treatment had a significant positive effect on the storage stability of seafood products at the storage temperature of $4^{\circ}C$ for 12 days. These results suggest that the storage period for fish fillets can be extended from 4 days to 6~8 days through the IPL treatment.

• Korean Journal of Microbiology
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• v.11 no.4
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• pp.181-188
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• 1973

For the bulk sterilization, there are two traditional methods of autoclaving and exposure to ethylene oxide. However, autoclaving involves high temperatures and pressures and ethylene oxide is chemically highly reactive, so these methods are radiation, we have carried out sterility and safety tests on some medical products irradiated at varying radiation levels. The results obtained were as follows ; 1) The minimum dose of radiation for the sterilization of medical products was 2.5 Mrad. 2) The radiosterilization dose varied depending on the initial population of microorganisms. 3) In transfusion sets, a level of radiation of 2.5Mrad at room temperature produced no pyrogen and they remained bacteriologically sterile.

• International Journal of Industrial Entomology and Biomaterials
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• v.39 no.1
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• pp.39-44
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• 2019

The effect of heat treatment on the sterilization and fatty acid compositions of silkworm powder was carried out under the guidance of Ministry of Food and Drug Safety. Food borne pathogens or microorganisms including E. coli, Salmonella spp., Listeria monocytogenes, Staphylococus aureus, Clostridium perfringens and aflatoxin, were not detected. The fatty acid composition was hardly changed after the silkworm powder was treated to a high temperature of $121^{\circ}C$. The low temperature sterilization of silkworm powder at $63^{\circ}C$ decreased the concentration of E. coli while high temperature sterilization at $121^{\circ}C$ has found no traces of microorganism.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.4 no.3
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• pp.185-193
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• 2000

A water treatment agent with antimicrobial activity(Ag-Os) was created by exchanging silver ion($Ag^{+}$) on calcined oyster shell powder. The desorption of the exchanged silver ion was negligible, thereby indicating a stable antimicrobial water treatment agent. The sterilization effect of Ag-Os on underwater microorganisms was then investigated. An MIC (Minimum Inhibitory Concentration) test result indicated that Ag-Os had an excellent sterilization effect on G-germs, such as Escherichia coli and Pseudomonas aeruginosa. Most germs were annihilated with an Ag-Os concentration of 200 ppm and contact time of 60 minutes. The sterilization effect was mainly dependent on the contact time. The zeta potential of the Ag-Os powder adsorbed on sand was measured relative to the concentration of exchanged silver ion. As the concentration of the exchanged silver ion increased, the surface charge density of the anions on the surface of the Ag-Os powder adsorbed on sand also increased. Accordingly, this result indicated that a higher silver ion than ion exchange capacity was present on the particle surface due to adsorption. Consequently, this increased concentration of exchanged silver ion would appear to significantly enhance the sterilization power.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.465-467
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• 1997

The comparative effects of ozone treatment and gamma irradiation on the sterilization, physicochemical properties and sensory quality of red pepper powder were investigated. As for the sterilization of microorganisms, 7.5~10 KGy of gamma irradiation completely eliminated the coliforms, yeast and molds, and total aerobic bacteria. On the other hand, ozone treatment failed to eliminate the highly contaminated microbial load, especially total aerobic bacteria. The physicochemical properties including capsaicin, capsanthin, browning, fatty acid compositions and sensory quality were not significantly changed by gamma irradiation up to 10 kGy, whereas ozone treatment caused significant changes in fatty acid compositions and destruction of natural pigments (p<0.05). The above results led us to conclude that gamma irradiation was more effective than ozone treatment for the sterilization and maintenance of physicochemical and sensory qualities of red pepper powders.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.3
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• pp.250-257
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• 2004

Recently, the use of UVC lamps inside building air-conditioning system has been increasing in both medical and nonmedical buildings for the control of environmental microorganisms. In the present study, irradiance performance test of UVC lamp was carried out and surface sterilization effect of UV ray was investigated by using UV ray irradiation experimental chamber and pilot system. Experimental results show that the effective irradiance of UVC lamp is strongly dependent on air velocity and temperature with exception of relative huminity in air-conditioning system. An individual microbiological kill effectiveness experiment also shows that the fractional kill of two microbiological samples such as E. Coli and Legionella is roughly the same as the estimated fractional kill in the case of chamber test and pilot system test.