• 한국환경보건학회지
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• 제38권4호
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• pp.300-310
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• 2012

Objectives: Indoor air quality problems in public spaces have recently become a very important issue in South Korea, because many spend a long time every day indoors. In this study, an extensive literature review was performed on the subject of suspended bacteria and fungi in public facilities. The objective of this study was to evaluate the extent and types of suspended bacteria and fungi in indoor air in South Korea. This study will provide direction to the research in the field of indoor air. Methods: Article reviews was conducted using a search engine and the following keywords; 'bacteria', 'total suspended bacteria', 'fungi' and 'indoor air' from published articles since 2000. Results: Most of the places of measurement were schools, kindergartens, childcare centers and general hospitals. The highest concentrations of total suspended bacteria and fungi were found in schools and kindergartens. Some public facilities exceeded the standard of 800 CFU/$m^3$. There were few studies on other suspended bacteria: Gram Negative Bacteria, Staphylococcus and Klebsiella pneumoniae. Conclusions: It appears that more studies with intensive controls are needed. It was found that schools and kindergartens were most susceptible to microbial indoor air pollution. These results may be able to suggest an indoor standard for suspended bacteria and fungi in South Korea.

• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.199-206
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• 2008

Four hundred and thirteen oxytetracycline-resistant bacteria were recovered from six freshwater giant prawn farms with a history of oxytetracycline use. Most oxytetracycline-resistant isolates were Gram-negative bacteria. Six groups of oxytetracycline-resistant bacteria were classified using cluster analysis based on a comparison of levels of oxytetracycline resistance. Complex fingerprint patterns were obtained for 71 isolates studied. In general, the band patterns of isolates from different ponds were very similar, and the data indicated that the isolates were closely related. The exploration for cross-resistance found that most of the 71 oxytetracycline-resistant isolates were also resistant to tetracycline and chlortetracycline, but had a relatively low resistance to doxycycline. Many isolates showed higher chlortetracycline resistance than oxytetracycline resistance. Additionally, the oxytetracycline-resistant isolates were examined for the presence of tetracycline resistance (tet) genes. Fifty percent of the isolates carried one of the 14 known tet genes examined. The most common determinants were TetA and TetD. However, TetB, TetC, TetE, TetK, TetL, and TetM were also found with various frequencies.

• 한국조리학회지
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• 제12권2호
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• pp.151-167
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• 2006

This study shows the differences among residents’ consciousness for general infectious disease and sterilization mediated by vermin. We categorized both industry-related people who work in restaurants, hygiene service shops, whole sales, government organizations, PC shops, factories, department stores and non-industry-related people who work in schools, general offices into two groups for this study. The discovery of vermin held 86% of total exam cases. The vermin included mosquitoes, cockroaches, ants, flies, and so on. People thought these vermin might mediate bacteria infection to human. 80.3% of persons thought mite might exist in blankets, beds and couches. Among 66.6% of total experience of vermin damage, the main damage came from mosquitoes. Frequently used methods of prevention from vermin damage were as follows: "spray of effective chemicals", "install traps" and " report to a prevention company" in order. It indicated that people did not take special actions to repel vermin in spite of their knowing seriousness of damage. Furthermore, just half cases were executed regular sanitization.

• 한국산업융합학회 논문집
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• 제16권2호
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• pp.41-46
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• 2013

On the purpose of helping the inhabitants living in farming, fishing villages, and islands for more safe and hygienic water from simple waterworks, experimental investigations were performed concerning the development of a water purifier with silver nanomaterial packed, having a function of the auto-disinfection. The results show as follows through such filteration and auto-disinfection processes. It is possible to get hygienic and safe water, for example, more than 95% of general bacteria, total coliforms, and fecal coliforms were removed. It is also possible to get good-quality water, for 49.4% of spent potassium permanganate and 85% and 63% of turbidity and conductivity were removed respectively. It is a very effective equipment, for 100% cost reduction of used chemicals was achieved by no-chemical disinfection process and THM was not generated.

• 센서학회지
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• 제27권4호
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• pp.237-241
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• 2018

The real-time enrichment and detection of pathogens are serious issues and rapidly evolving field of research because of the ability of these pathogens to cause infectious diseases. In general, bacterial detection is accomplished by conventional colony counting or by polymerase chain reaction (PCR) after DNA extraction. As colony counting requires considerable time to cultivate, PCR is an attractive method for rapid detection. A small number of pathogens can cause diseases. Hence, a pretreatment process, such as enrichment is essential for detecting bacteria in an actual environment. Thus, in this study, we developed a microfluidic chip capable of performing rapid enrichment of bacteria and the extraction of their genes. A lectin, i.e., Concanavalin A (ConA), which shows binding affinity to the surface of most bacteria, was coated on the surface of magnetic particles to nonspecifically capture bacteria. It was subsequently concentrated through magnetic forces in a microfluidic channel. To lyse the captured bacteria, magnetic particles were irradiated by a wavelength of 532nm. The photo-thermal effect on the particles was sufficient for extracting DNA, which was consequently utilized for the identification of bacteria. Our device will help monitor the existence of bacteria in various environmental situations such as water, air, and soil.

• 한국축산식품학회지
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• 제28권5호
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• pp.675-680
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• 2008

The physical quality and microbial safety of Korean beef jerky was evaluated at various steps during its preparation. Microbial counts in raw beef demonstrated mesophillic bacteria at 4.20 Log CFU/g, psychrotrophic bacteria at 3.85 Log CFU/g, anaerobic bacteria at 4.90 Log CFU/g, and yeast and molds at 1.92 Log CFU/g. Spore-forming bacteria and coliforms were not detected in raw beef samples. Spices and spiced meats showed similar trends in microbial counts, demonstrating minimal microbial contamination during these stages of preparation. The final beef jerky product exhibited counts of mesophillic bacteria at 1.15-1.66 Log CFU/g, psychrotrophic bacteria at 1.15-1.66 Log CFU/g, and anaerobic bacteria at 0.81-1.72 Log CFU/g. Spore-forming bacteria, yeast and molds, and coliforms were not detected in beef jerky. Significant differences from added ingredients occurred for instron textural profile analysis traits for hardness. In general, Korean beef jerky with humectant and tenderizer had lower hardness than control (without humectant and tenderizer). Also, the sample added with 0.01% protease from Streptomyces griseus had lower hardness than all samples. All samples had 0.7l to 0.72 water activities, and the color and pH were not shown in significant changes of all samples.

• 한국식품조리과학회지
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• 제25권2호
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• pp.170-179
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• 2009

This study examined effects on shelf-life extension and prevention of starch retrogradation in rye-wheat mixed bread (RWMB) samples prepared with substitutions of 20, 40, 60, and 80% rye sourdough (RSD) as well as a control made with the addition of naturally fermented raisin extract. These effects were investigated using mold growth, water activity, and textural characteristics during a storage period of 8 days at $20^{\circ}C$. The activities of the rye sourdough were examined in terms of pH, total titratable acidity, general bacteria, lactic acid bacteria, and yeast counts. As the incubation time of the sour dough increased, pH decreased, while total titratable acidity increased. General bacteria, lactic acid bacteria, and yeast counts increased with increasing incubation time. Mold grew on the external surface of the control group after 6 days and on the surface of the RSD bread samples after 8 days, respectively. With regard to water activity, the control group had increasing activity as the storage period increased. In addition, the 20, 40, 60, and 80% RSD samples had increasing water activities until the 4th day however, these strongly decreased by the 6th day. In terms of textural characteristics, as the storage period increased, hardness increased, while springiness, cohesiveness, and resilience decreased. There were no significant differences in gumminess among the samples. The control, 20, 40, and 60% RSD samples had decreases in chewiness with increasing storage time, however, the 40% RSD sample did not differ significantly during the storage period. Finally, water activity was negatively correlated with hardness (p<0.05). In conclusion, the results indicate that substituting rye sourdough in rye-wheat mixed bread has a prolongation effect on shelf-life, but no effect on the prevention of starch retrogradation.

• 한국안광학회지
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• 제18권2호
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• pp.101-106
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• 2013

목적: 본 연구는 시력교정용 안경에서 범용 적으로 활용되고 있는 세척방법에 따른 오염 균의 제균 효과를 알아보고자 하였다. 방법: 실험대상 82명의 안경으로부터 세척 전후에 대한 각각의 세균을 채취하여 제균 여부를 확인하였다. 결과: 수돗물을 이용하여 초음파세척을 실시한 결과 세균 종의 수에 대한 변화가 없었으며 70% 소독용 알코올을 이용하여 초음파세척을 실시하였을 때는 46.2%의 제균 효과가 나타났으며 일반 세제를 이용하여 솔 세척 후 70% 알코올을 이용한 초음파세척을 실시한 결과 85.7%의 제균 효과가 나타났다. 결론: 시력교정용 안경에 존재하는 기회감염성 세균들은 세제를 이용하여 솔질 세척이 더욱 효과적이었는데 이것은 렌즈와 림의 틈새 등 접합부위 등에 세균들이 세제와 솔에 의해 제거 된 것으로 차후 청결한 안경의 관리를 위하여 안경의 정기적 분해 세척이 요구됨과 동시에 안경세척관리에 대한 가이드라인이 구축되어야 할 것으로 사료된다.

• 한국조리학회지
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• 제21권2호
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• pp.1-10
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• 2015

본 연구에서는 조미김 식품제조 가공 업소에서 제조한 조미김을 대상으로 주요 원료 및 제조공정별 생물학적 위해요소분석을 실시하여 생물학적 중요관리점(CCP)을 파악하고, 이를 관리하고 모니터링하기 위한 한계기준을 설정하여 HACCP Plan을 제시하고자 한다. 본 연구 결과, 일반세균수는 2차 가열공정 이전에서는 $10^3{\sim}10^4CFU/g$의 높은 수준으로 검출되었으나, 2차 가열 이후에서는 $1.0{\times}10CFU/g$ 미만으로 검출되었다. 조미김의 제조공정별 병원성미생물 분석결과, 모든 제조공정에서 검출되지 않았다. 이와 같은 결과로 조미김의 제조 유통시 CCP는 2차 가열 과정으로 결정되었다. 가열온도를 $170{\pm}5^{\circ}C$, $200{\pm}0.5^{\circ}C$, $230{\pm}5^{\circ}C$로 하고, 각각의 온도에서 가열시간을 $3.0{\pm}5$초, $4.0{\pm}0.5$초, $5.5{\pm}0.5$초로 실시하면서 일반세균과 병원성미생물을 시험한 결과, 2차 가열 전 병원성 미생물은 음성이었다. 일반세균은 $230{\pm}5^{\circ}C$일 때 현저히 감소되었고, 특히 가열시간을 $5.5{\pm}0.5$일 때 $1.0{\times}10CFU/g$ 이하로 나타났다. 미생물학적 위해요소를 HACCP 시스템에 적용하여 생산한 조미김의 경우 상품가치와 품질, 안전성을 확보하기에 가장 적절한 가열온도와 가열시간은 $230{\pm}5^{\circ}C$, 가열시간은 $5.5{\pm}0.5$초로 한계기준을 설정하였다. 본 연구를 통하여 제조공정별 위해요소분석을 활용하여 조미김의 중요관리점 및 한계기준을 설정하였고, 이를 통하여 HACCP 계획을 수립하고, 사후관리 등에 활용할 수 있다.

• 한국미생물·생명공학회지
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• 제22권5호
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• pp.453-458
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• 1994

Intestinal microbial flora comprise one third of the large intestinal contents in human. They play a significant effects through beneficial and harmful action on the human health. This is the first study which examined the composition of the microflora of the general population in Korea. Bacteroides, Bifidobacterium, Eubacterium, Peptostreptococcus, Lactobacillus, Streptococcus, Escherichia coli, Staphylococcus, Clostridium perfringens, total aerobic bacteria and total anaerrobic bacteria were counted using various selective and non-selective media. Among the bacteria studied the number of Bifidobacterium were greatest in breast-fed infants(30-90 days old), whereas Streptocuccus and Bifidobacterium in bottle-fed infants. In 20-40 age group Bacteroides were predominant followed by Bifidobacterium and Eubacterium. In early group(over 65 years old) Bacteroides were predominant followed by Eubacterium and bifidobacterium. The frequency and number of Cl. perfringens were highest in dlderly group. These results confirm that the microfloral pattern in large intestine change during the life cycle of humans.