• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.288-292
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• 2006

Through statistically designed experiments, lysis agents were optimized to effectively disrupt bacterial cells in a microfluidic device. Most surfactants caused the efficient lysis of Gram-positive microbes, but not of Gram-negative bacteria. A Plackett-Burman design was used to select the components that increase the efficiency of the lysis of the Gram-negative bacteria Escherichia coli. Using this experimental design, both lysozyme and benzalkonium chloride were shown to significantly increase the cell lysis efficiency, and ATP was extracted in proportion to the lysis efficiency. Benzalkonium chloride affected the cell membrane physically, while lysozyme destroyed the cell wall, and the amount of ATP extracted increased through the synergistic interaction of these two components. The two-factor response-surface design method was used to determine the optimum concentrations of lysozyme and benzalkonium chloride, which were found to be 202 and 99 ppm, respectively. The lysis effect was further verified by microscopic observations in the microchannels. These results indicate that Gram-negative cells can be lysed efficiently in a microfluidic device, thereby allowing the rapid detection of bacterial cells using a bioluminescence-based assay of the released ATP.

• 한국식품위생안전성학회지
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• 제36권1호
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• pp.42-50
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• 2021

외식산업의 급속한 성장과 함께 호텔을 비롯한 외식업체에서는 식품안전 요구 및 위생에 대한 중요성 이 증가하고 있다. 이에 현장에서 위생상태를 판단할 수 있는 신속하고 실용적인 모니터링기법이 요구된다. 본 연구는 국내5성급 호텔 5군데를 대상으로 개인위생(작업자의 손), 조리기구(칼, 도마, 식품보관용기, 슬라이스 머신 칼날, 제빙기 스쿱), 시설·설비(냉장고 손잡이, 작업대, 싱크대), 고객 접점항목(뷔페용 집게)에 대한 위생관리 실태를 조사하였고 그에 대한 검증법인 ATP 값의 상관관계를 도출하고자 하였다. 5개 호텔의 위생관리 실태조사 결과, 다른 검사 항목보다 상대적으로 조리기구 및 개인위생 결과가 비교적 위생적으로 관리되고 있었으며(조리기구 92.2%, 개인위생 91.4%, 시설·설비 76.19%, 고객 접점항목 88.6%)으로 시설·설비는 비교적 미흡한 것으로 나타났다. ATP검사 결과, 조리 기구(51±45 RLU/25 ㎠)는 시설·설비(167±123 RLU/25 ㎠)보다 비교적 위생적으로 잘 관리되었다. 위생실태 조사 결과 점수와 ATP 값의 상관성 분석을 실시한 결과, 각 호텔 별 작업자 손, 조리기구, 시설·설비의 대부분 음의 상관관계를 가지며 높은 상관성(-0.64 - -0.89)을 보였다. 또한 이번 연구에서 각 검사 항목의 평소 상태의 ATP 값(1020±1254 RLU/25 ㎠)에 비해 세척 후 ATP 값(92±67 RLU/25 ㎠)이 현저히 감소되어 세척의 유효성을 확인하는 도구로 적합성을 확인할 수 있었다. 호텔을 비롯한 외식업체에서 수행하는 주관적인 위생실태조사와 ATP 검사법을 병행한다면, 실시간으로 보이지 않는 오염물질의 객관적인 수치화를 통해 식품사고 발생을 예방하기 위한 효과적인 모니터링 방법이 될 것으로 사료된다.

• Journal of Microbiology
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• 제38권2호
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• pp.74-79
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• 2000

For the demonstration of a novel riboflavin kinase assay method based on the bacterial bioluminescence, partially purified riboflavin kinase was prepared from bovine liver through ammonium sulfate precipitation and DEAE-cellulose ion exchange chromatography. Using bacterial luciferase from Photobacterium phosphoreum and the dithionite reduction method, and easy, safe, and fast assay method was established. The optimal temperature, pH, Km values form riboflavin and ATP of boving liver riboflavin kinase determined with this luminescence method were 35$^{\circ}C$, pH 7, 15.3${\mu}$M and 8.3.${\mu}$M, respectively. The detection limit of FMN produced by riboflavin kinase was in the range of 200 pM to 4${\mu}$M which is comparable to the HPLC-fluorescence detection method, while the detection time for each assay was less than 15 sec compared to the HPLC method which requeires at least 10 min for completion.

• 대한영양사협회학술지
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• 제17권2호
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• pp.142-160
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• 2011

The purpose of this study was to investigate food sanitation status in elderly welfare facilities and assess the performance of food sanitation practices. Twenty elderly welfare facilities out of 85 located in Seoul with a capacity of fewer than 50 persons participated. The food sanitation status of worktable, kitchen utensils (knives, cutting boards, ladles, spoons), and tableware and bowls were examined by ATP bioluminescence. The results found that the ATP value of knife was the highest. Those of ladles appeared relatively higher than others. Meanwhile, the tableware and bowls, although washed everyday after meals, had the lowest ATP value. This study also conducted a survey on the food sanitation practices of 32 cooking employees in the 20 facilities. Fifty-six percent were in their 40s, and 53% had graduated from high school. More than half (66%) of them had no certification of cooking. Half of the respondents had worked for at least 5 years in food service facilities, and had received food sanitation training. Among them, 31% said they applied food sanitation training while working, and 47% responded the training was very helpful. The foodservice employees demonstrated good food sanitation practices. The results show that food sanitation performance of the workers significantly differed according to their age, education level, total work experience in food service facilities, chef certification, and prior food sanitation experience.

• Journal of Microbiology and Biotechnology
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• 제33권11호
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• pp.1506-1512
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• 2023

Quantitative analysis of adenosine triphosphate (ATP) has been widely used as a diagnostic tool in the food and medical industries. Particularly, the pathogenesis of a few diseases including inflammatory bowel disease (IBD) is closely related to high ATP concentrations. A bioluminescent D-luciferin/luciferase system, which includes a luciferase (FLuc) from the firefly Photinus pyralis as a key component, is the most commonly used method for the detection and quantification of ATP. Here, instead of isolating FLuc produced in recombinant Escherichia coli, we aimed to develop a whole-cell biocatalyst system that does not require extraction and purification of FLuc. To this end, the gene coding for FLuc was introduced into the genome of probiotic Saccharomyces boulardii using the CRISPR/Cas9-based genome editing system. The linear relationship (r² = 0.9561) between ATP levels and bioluminescence generated from the engineered S. boulardii expressing FLuc was observed in vitro. To explore the feasibility of using the engineered S. boulardii expressing FLuc as a whole-cell biosensor to detect inflammation biomarker (i.e., ATP) in the gut, a colitis mouse model was established using dextran sodium sulfate as a colitogenic compound. Our findings demonstrated that the whole-cell biosensor can detect elevated ATP levels during gut inflammation in mice. Therefore, the simple and powerful method developed herein could be applied for non-invasive IBD diagnosis.

• 한국식품위생안전성학회지
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• 제24권3호
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• pp.277-284
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• 2009

외식산업의 빠른 성장과 함께 호텔을 비롯한 일반음식점에서의 식중독의심사건 발생빈도가 증가하고 있어 현장에서 신속하고 간편하게 위생상태를 판단할 수 있는 모니터링기법이 필요하게 되었다. 본 연구는 서울시내 5개 호텔을 대상으로 개인위생 (작업자의 손), 조리기구 (칼, 도마, 행주, 캔오프너, 식품보관용기, 슬라이스머신칼날), 시설 설비 (냉장고손잡이, 작업대, 싱크대)에 대한 위생관리 실태를 조사하였고 그에 대한 검증법인 ATP 조사법의 상관관계를 도출하고자 하였다. 5개 호텔의 위생관리 실태조사 결과, 50점 만점 중 개인위생 46.6점, 조리기구 위생관리 40.2점, 시설 설비 위생관리 40.3점으로 개인위생은 비교적 관리가 잘 되고 있었으며, 조리기구와 시설 설비의 위생관리는 미흡한 것으로 나타났다. ATP검사 결과, 작업자의 손은 $40.8{\pm}6.77\;RLU/cm^2$로 조리기구와 시설 설비에 비해 높은 값을 보였으나, 모두 1,000 RLU/$cm^2$의 기준 이하로 위생관리 상태가 양호한 것으로 나타났다. 위생실태조사 결과 점수와 ATP 값의 상관성 분석을 실시한 결과, 각 호텔별 작업자 손, 조리기구, 시설 설비 모두에서 음의 상관관계를 가지며 높은 상관성을 보였다 ATP검사법은 신속, 간편, 일관성을 바탕으로 호텔을 비롯한 외식업체에서 감시원이 수행하는 주관적인 위생실태조사를 대체 할 수 있는 객관적인 위생관리 방법이 될 것으로 판단된다.

• The Journal of Advanced Prosthodontics
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• 제12권4호
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• pp.233-238
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• 2020

PURPOSE. This study aims to compare the marginal fitness of two types of implant-supported fixed dental prosthesis, i.e., cementless fixation (CL.F) system and cement-retained type. MATERIALS AND METHODS. In each group, ten specimens were assessed. Each specimen comprised implant lab analog, titanium abutment fabricated with a 2-degree tapered axial wall, and zirconia crown. The crown of the CL.F system was retained by frictional force between abutment and relined composite resin. In the cement-retained type, zinc oxide eugenol cement was used to set crown and abutment. All specimens were sterilized with ethylene oxide, immersed in Prevotella intermedia culture in a 50 mL tube, and incubated with rotation. After 48 h, the specimens were washed thoroughly before separating the crown and abutment. The bacteria that penetrated into the crown-abutment interface were collected by washing with 500 µL of sterile saline. The bacterial cell number was quantified using the agar plate count technique. The BacTiter-Glo Microbial Cell Viability Assay Kit was used to measure bacterial adenosine triphosphate (ATP)-bioluminescence, which reflects the bacterial viability. The t-test was performed, and the significance level was set at 5%. RESULTS. The number of penetrating bacterial cells assessed by colony-forming units was approximately 33% lower in the CL.F system than in the cement-retained type (P<.05). ATP-bioluminescence was approximately 41% lower in the CL.F system than in the cement-retained type (P<.05). CONCLUSION. The CL.F system is more resistant to bacterial penetration into the abutment-crown interface than the cement-retained type, thereby indicating a precise marginal fit.