• 센서학회지
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• 제32권4호
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• pp.213-218
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• 2023

Triboelectric nanogenerators (TENGs) have emerged as a highly promising energy harvesting technology capable of harnessing mechanical energy from various environmental vibrations. Their versatility in material selection and efficient conversion of mechanical energy into electric energy make them particularly attractive. TENGs can serve as a valuable technology for self-powered sensor operation in preparation for the IoT era. Additionally, they demonstrate potential for diverse applications, including energy sources for implanted medical devices (IMDs), neural therapy, and wound healing. In this review, we summarize the potential use of this universally applicable triboelectric energy harvesting technology in the disinfection and blocking of pathogens. By integrating triboelectric energy harvesting technology into human clothing, masks, and other accessories, we propose the possibility of blocking pathogens, along with technologies for removing airborne or waterborne infectious agents. Through this, we suggest that triboelectric energy harvesting technology could be an efficient alternative to existing pathogen removal technologies in the future.

• 한국가금학회지
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• 제37권1호
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• pp.35-41
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• 2010

본 연구는 계란의 위생화 및 저장성 연장에 관한 연구의 일환으로 키토산 코팅 및 감마선 조사 병용처리에 의한 계란에 오염된 위해 미생물 제어 및 영양학적 특성을 평가하였다. 키토산 코팅과 감마선 조사 병용처리한 계란에 E. coli를 접종한 결과 2 kGy 방사선 조사에 의해 검출한계 이하 수준으로 감소하였으며, 키토산 코팅시 3일 후부터 검출되지 않았다. 수분, 조단백질 및 조회분 등 일반 성분은 난백 및 난황 모두에서 차이를 나타내지 않았으며, retinol, 인지질과 미량 원소의 함량도 처리에 따른 차이가 없었다. 난황의 콜레스테롤 및 carotenoid의 함량은 키토산 코팅 유무와 상관없이 방사선 조사에 의해 그 함량이 감소하였다(P<0.05). 따라서 키토산 코팅(1%)과 감마선 조사(2 kGy) 병용처리는 계란의 미생물학적 안전성을 확보할 수 있으며, 영양학적 성분변화에 큰 영향을 끼치지 않아, 향후 계란의 위생화 및 저장성 연장을 위해 산업적으로 적용이 가능할 것이라고 판단된다.

• 대한환경공학회지
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• 제32권7호
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• pp.722-729
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• 2010

하수 재이용에 대한 관심이 급부상하고 있는 가운데, 재이용수의 미량물질 등에 의한 화학적 리스크와 더불어 미생물학적 안전성에 대한 고려가 요구되고 있다. 본 연구에서는 벤치스케일의 연속식 실험장치를 이용, 미량물질 중 최근 주목을 받고 있는 의약품류를 대상으로, UV처리공정의 의약품류 제거효과 및 미생물학적 안전성의 달성 가능성을 고찰하였다. 시험수로 이용한 하수 2차 처리수중에서는 항생물질, 해열진통제 등 38종의 의약품류가 수 ng/L에서 수백 ng/L의 범위로 검출되었으며, 이를 대상으로 하여 UV 및 UV/$H_2O_2$ 처리실험을 행한 결과, UV 단독처리에 의한 의약품류의 효과적인 제거에는 상당량의 UV조사량이 필요할 것으로 예상되었다. 반면, UV/$H_2O_2$ 공정의 경우 $H_2O_2$의 첨가농도를 약 1 mg/L에서 6mg/L까지 증가시킴에 따라 각 의약품류의 제거율은 점점 증가하는 것으로 나타났다. 한편, $923\;mJ/cm^2$의 UV 조사량과 6.2 mg/L의 $H_2O_2$를 병용한 UV/$H_2O_2$ 처리는 Naproxen(>89%)외 모든 의약품류의 농도를 90% 이상까지 감소시킬 수 있었다. 또한 이 운전조건은 현행 하수처리장 유출수중의 대장균군에 대한 규제농도($3,000/cm^3$)를 기준으로 하였을 때, 4~5 log의 불활성화를 달성할 수 있을 것으로 예상되어, 하수 재이용에 요구되는 California Title 22의 criteria를 만족시킬 수 있을 것으로 판단되었다.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.1061-1065
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• 2001

The antibacterial effects of water extracts of Scutellariate Radix (a dried root of Scutellaria baicalensis GEORGI) and its major flavonoid components, Baicalin and Baicalein, on Salmonella typhimurium, a representative enteric pathogen, were studied. Through a Kriby-Bauer disc analysis, the growth-inhibition activity of Scutellariae Radix against. S. typhimurium was found to be compatible with commercial antibiotics, such as ampicillin, chloramphenicol, and streptomycin. In contrast, the growth of a nonpathogenic E. coli strain was unaffercted by Scutellariae Radix. To examine the effect of polyphosphate kinase (ppk), a putative virulence factor, on the antibacterial activity of Scutellariae Radix, the growth profile of a ppk mutant of S. typhimurium was investigated in a tryptic soy broth containing different concentrations of water extracts of Scutellariae Radix. The ppk mutant was able to grow in 6 mg/ml of water extracts of Scutellariae Radix, whereas in 6 mg/ml of water extracts of Scutellariae Radix, whereas the wild-type could not, implying that the inactivation of ppk made S. typhimurium more resistant to the antibacterial activity of Scutellariae Radix. No enhanced resistance was observed in a ppk mutant of S. typhimurium complemented with a ppk expression vector. The attenuation of the virulence by ppk inactivation was also observed in a virulence assay using BLAB/c mice. Neither Baicalin nor Baicalein exhibited any growth-inhibition activity against S. typhimurium. The water extracts of Scutellariae Radix stimulated the transcription of ppk, especially in the early growth-stage of S. typhimurium.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.932-945
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• 2009

Several species of Gram-positive bacteria have cell wall peptidoglycan (syn. murein) in which not all of the sugar moieties are N-acetylated. This has recently been shown to be a secondary effect, caused by the action of a peptidoglycan N-acetylglucosamine deacetylase. We have found that the opportunistic pathogen Listeria monocytogenes is unusual in having three enzymes with such activity, two of which remain in the cytoplasm. Here, we examine the enzyme (PgdA) that crosses the cytoplasmic membrane and is localized in the cell wall. We purified a hexa-His-tagged form of PgdA to study its activity and constructed a mutant devoid of functional Lmo0415 (PgdA) protein. L. monocytogenes PgdA protein exhibited peptidoglycan N-acetylglucosamine deacetylase activity with natural substrates (peptidoglycan) from both L. monocytogenes and Escherichia coli as well as the peptidoglycan sugar chain component N-acetylglucosamine, but not with N-acetylmuramic acid. As was reported recently [6], inactivation of the structural gene was not lethal for L. monocytogenes nor did it affect growth rate or morphology of the cells. However, the pgdA mutant was more prone to autolysis induced by such agents as Triton X-100 and EDTA, and is more susceptible to the cationic antimicrobial peptides (CAMP) lysozyme and mutanolysin, using either peptidoglycan muramidases or autolysis-inducing agents. The pgdA mutant was also slightly more susceptible than the wild-type strain to the action of certain beta-lactam antibiotics. Our results indicate that protein PgdA plays a protective physiological role for listerial cells.

• Journal of Animal Science and Technology
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• 제54권3호
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• pp.191-198
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• 2012

The objective of this study was to evaluate the potential use of a dielectric barrier discharge (DBD) plasma system to improve microbial safety of sliced cheese. The atmospheric pressure plasma (APP) effect on visual appearance and a sensory evaluation were also carried out. The number of Escherichia coli inoculated on cheese slices decreased by 0.09, 0.47, 1.16 and 1.47 log cycles with helium (4 liters/min [lpm]) and 0.05, 0.87, 1.89 and 1.98 log cycles with He/$O_2$ mixture (4 lpm/15 standard cubic centimeters per minute), after being treated with plasma for 1, 5, 10, and 15 min, respectively. Significant reductions were also observed in Staphylococcus aureus inoculated onto cheese slices ranging from 0.05 to 0.45 log cycles with He and from 0.08 to 0.91 log cycles with He/$O_2$-treated samples, respectively. Adding oxygen resulted in a significant increase in inactivation of both pathogens. No visible change in the plasma-treated cheese slices was observed even though the instrumental analysis showed a significant decrease in the $L^*$-value and an increase in the $b^*$-value. The cheese slices were damaged after 10 and 15 min of plasma treatment. In addition, significant reductions in sensory quality including flavor, odor, and acceptability of plasma-treated cheese slices were observed. The results indicate that the DBD plasma system has potential for use in sanitizing food products, although the effect was limited. Further development of the APP system is necessary for industrial use.

• 한국어병학회지
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• 제33권1호
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• pp.97-101
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• 2020

Although aquaculture production rates grown over the years, aquatic animal diseases occur every year which causes substantial economic losses. When an aquatic animal is infected with an aquatic animal pathogen it is either incinerated or buried according to the aquatic life disease control act. Although these methods prevent the spread of disease, it is not environment friendly. Here, we developed an aquatic animal rendering equipment for disposal of fish waste which is environment-friendly and efficient. Also, fertilizer components of fish waste were evaluated value for recycling. The mobile rendering equipment was designed for field operation and/or high temperature and pressure system, oil and water separator, and shredding drying apparatus. During the experiment (July-2016 to November-2016), a total of 53,824 kg fish waste was collected, and 29,216 kg compost of rendering by-product was made. Also, compost made from viral (Viral hemorrhagic septicemia virus) infected fish did not reflect any detectable pathogen. The concentration of nitrogen, phosphorus, and organic matter in the fish waste compost were 2.17%, 26.98%, and 92.44%, respectively. The results suggest that fish waste used in this study was decomposed efficiently as per the official standard for fertilizer product. This equipment can be useful for efficient inactivation of the aquatic animal pathogenic agents and recycling of the fish waste in an environment-friendly manner.

• 한국축산식품학회지
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• 제30권4호
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• pp.603-608
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• 2010

This study investigated the effects of electron beam irradiation on pathogens, quality, and functional properties of shell eggs during storage. A 1st grade 1-d-old egg was subjected to electron beam irradiation at 0, 1, 2, and 3 kGy, after which the number of total aerobic bacteria, reduction of inoculated Escherichia coli and Salmonella Typhimurium, egg quality, and functional properties were measured. Electron beam irradiation at 2 kGy reduced the number of E. coli and S. Typhimurium cells to a level below the detection limit (<$10^2$ CFU/g) after 7 and 14 d of storage. Egg freshness as measured by albumen height and the number of Haugh units was significantly reduced by 1-kGy irradiation. The viscosity of irradiated egg white was also significantly decreased by increased irradiation, whereas its foaming ability was increased. Electron beam irradiation also increased lipid oxidation in egg yolks. These results suggest that electron beam irradiation reduces the freshness of shell eggs while increasing the oxidation of egg yolk and improving important functional properties such as foaming capacity. Electron beam irradiation can also be applied to the egg breaking process since the irradiation reduces the viscosity of egg white, which can allow egg whites and yolks to be separated with greater efficiency.

• 대한환경공학회지
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• 제32권12호
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• pp.1134-1140
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• 2010

미량오염물질의 산화 및 대체 소독제로 각광받는 오존처리의 하수 2차 처리수중에 잔류하는 의약품류에 대한 제거 성능을 검토하였다. 또한, 의약품류의 제거를 목적으로 한 오존처리에 의한 미생물의 불활성화에 대하여 고찰하였다. 본 연구에서는 시험수로써 하수 2차 처리수를 이용하였으며, 오존처리는 2 mg/L, 4 mg/L, 6 mg/L의 오존 주입량으로 행하였다. 오존처리에 의해 시험수중에서 검출된 37종의 의약품류를 효과적으로 제거하기 위해서는 6 mg/L의 오존 주입량 (오존 소비량 : 4.4 mg/L)이 요구되었다. 동일한 오존처리 조건하에서는 대장균군 및 enteroviruses에 대해 약 3 log의 불활성화가 달성가능할 것으로 고찰되어, 잔류 의약품류의 제거 뿐만 아니라 병원성 미생물에 대해서도 효과적인 소독효과를 달성할 수 있을 것으로 판단되었다. 반면, 6 mg/L의 오존 주입량을 이용한 오존처리시, 처리수중의 용존오존농도가 약 1.8 mg/L까지 증가하여, 발암성 물질인 브로메이트의 생성가능성이 높아질 것으로 예상되었다. 이러한 브로메이트의 생성을 억제하기 위해서는 오존처리와 UV 또는 $H_2O_2$와의 조합공정인 고도산화처리공정에 대한 검토가 필요할 것으로 판단되었다.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.1021-1026
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• 2003

Numerous secreted and cell-associated virulence factors have been proposed to account for the fulminating and destructive nature of Vibrio vulnificus infections. Among the putative virulence factors are an elastase, elastolytic protease, and a cytolytic hemolysin. Effects of the elastase on the hemolysin were assessed by evaluating changes of hemolytic activities either in the presence or absence of the protease. Although hemolytic activity in the culture supernatant was lowered by the purified elastase added in vitro, the cellular level of hemolytic activity was unaffected by the mutation of vvpE encoding the elastase. Growth kinetic studies revealed that hemolysin reached its maximum level in the exponential phase of growth, and the elastase appeared at the onset of the stationary phase. These results have provided insight into the regulation of virulence factors: temporally coordinate regulation of virulence factors is essential for the overall success of the pathogen during pathogenesis.