다환 방향족 탄화수소(PAH) 분해 미생물 탐색을 위한 승화법의 개발

권태형,김준태,김종식,Kwon, Tae-Hyung,Kim, Jun-Tae,Kim, Jong-Shik 한국미생물학회 2010 미생물학회지 Vol.46 No.1

다환 방향족 탄화수소(PAH; polycyclic aromatic hydrocarbon)는 발암성, 돌연변이 유발성, 유전독성을 지니기 때문에 인체위해성이 큰 물질로 알려져 있다. 기존 PAH 분해 미생물 탐색 방법중 독성이 강한 유기용매에 PAH를 용해시켜 미생물에 직접 분무하는 분무법, 미생물과 직접 혼합하는 한천중층법은 미생물 생장에 영향을 줄 뿐만 아니라, 특히 많이 쓰이는 분무법의 경우 분무되는 PAH의 양을 조절하기가 어렵고 멸균상태를 유지하기가 힘들다는 단점이 있다. 그래서 본 논문에서는 이와 같은 단점을 보완한 방법으로 승화법(Alley, Jeremy F. and Lewis R. Brown. 2000. Use of sublimation to prepare solid microbial media with water-insoluble substrates. Appl. Environ. Microbiol. 66, 439-442)을 도입하여 적용하였다. 그 결과 상용휘발유 및 태안유류유출지 시료로부터 분리한 350분리균주 중에서 7균주가 단일 PAH 또는 복수의 PAH 분해에 관여했다. 특히 Corynebacterium sp. SK20, Rhodococcus sp. TA24, Streptomyces sp. TA27은 시험한 pyene, phenanthrene, naphthalene에, Gordonia sp. H37는 pyrene, naphthalene에, Arthrobacter sp. S49는, naphthalene, phenanthrene에 활성이 있었다. Recent studies have described various microorganisms that can degrade PAH, however, there are currently limited methods available to screen for PAH-degrading microorganisms. To screen for PAH-degrading microorganisms, a sublimation method (Alley, Jeremy F. and Lewis R. Brown. 2000. Appl. Environ. Microbiol. 66, 439-442) was modified to produce a simple screening system. In our results, there were several bacterial species capable of pyrene degradation including genera, Coryenbacterium, Gordonia, Rhodococcus, and Streptomyces, which have been screened from 350 bacterial isolates of commercial gasoline and oil-spilled sediment by the sublimation method. The main advantage of this method is that it (i) safely deposits an even, thin and visible layer of PAH onto the agar surface without the use of solvents and (ii) the quantity of PAH sublimed onto the agar can be easily controlled. Overall, this sublimation method may be an effective and simple technique to screen for PAH-degrading microorganisms.

Antimicrobial activity and protective effect of Geranium thunbergii against oxidative DNA damage via antioxidant effect

권태형,이수진,박재호,김태완,박정자,박년호,Kwon, Tae-Hyung,Lee, Su-Jin,Park, Jae-Ho,Kim, Taewan,Park, Jung-Ja,Park, Nyun-Ho The Korean Society of Food Preservation 2017 한국식품저장유통학회지 Vol.17 No.5

본 연구에서는 현초의 식품소재 적용과 기능성 소재의 개발을 위해 현초 에틸 아세테이트 분획물을 이용하여 활성산소종의 소거활성과 산화적 DNA 손상 보호효과 및 항균활성에 대해 검증하였다. 현초를 메탄올로 추출하여 얻어진 추출물에 대해 n-hexane, chloroform, ethyl acetate, n-butanol, water의 용매를 이용하여 순차분획을 실시하였고, 얻어진 결과물에 대하여 다양한 항산화 측정 방법을 통하여 항산화 효능을 측정한 결과 에틸 아세테이트 분획물의 경우 DPPH 라디칼 소거능, ABTS 라디칼 소거능 및 환원력에서 효과가 높게 측정 되었으며, $50{\mu}g/mL$의 농도에서 각각 80.88%, 80.12%, 28%를 저해하는 것으로 측정되었다. 이러한 항산화 효능과 함께 산화적 DNA 손상 보호효과를 검증하였고 농도별로 억제하는 경향을 나타냈다. 또한 식품 소재 및 다양한 첨가 소재로 이용하기 위하여 항균활성을 측정하였으며, 에틸 아세테이트 분획물에서 연구에 사용된 모든 균주에 대하여 저해 활성을 보였다. 이러한 활성을 가진 현초 에틸 아세테이트 분획물의 활성물질을 검증하기 위하여 phenolic compound 및 flavonoid 대조군을 이용하여 LC 분석을 하였다. 그 결과 ellagic acid와 gallic aicd가 검출 되었으며 각각 55.14 mg/g, 5.42 mg/g 측정 되었다. 이는 결과적으로 현초는 다양한 식품소재로서의 활용될 수 있으며, 본 논문은 기능성 물질로 활용을 위한 기초자료가 될 것으로 사료 된다. This study aimed to investigate the various biological activities of Geranium thunbergii such as antimicrobial activity and protective effect against oxidative damage. To evaluate its antioxidant and antimicrobial activities, we first performed methanol extraction; this methanol extract was further partitioned using various solvents. And then, its antioxidant activity was measured using various assays including total phenolic content and protection against oxidative DNA damage, and antimicrobial activities were examined using minimum inhibiting concentration (MIC) test, and paper disc method. In addition, high-performance liquid chromatography was performed to analyze the major chemical components of ethyl acetate fraction. The G. thunbergii fraction with ethyl acetate exhibited higher antioxidant and antimicrobial activities than the other fractions. The results showed that G. thunbergii ethyl acetate fraction at $50{\mu}g/mL$ had strong DPPH and ABTS radical scavenging activities of 80.88% and 80.12%, respectively. In addition, the ethyl acetate fraction protected DNA from the oxidative damage induced by ferrous ion and hydroxyl radicals and showed high antimicrobial activity with diameter of inhibition zones ranging from 13.33 to 15.67 mm. High-performance liquid chromatography analysis revealed the major phenolic compounds of G. thunbergii to be ellagic acid and gallic acid. These results suggest that G. thunbergii might protect DNA against oxidative stress induced by reactive oxygen species and can be utilized as a natural source of antioxidant and antimicrobial agent in the food industry.

A New Disinfestation Approach Against Some Greenhouse Pests Using Ethyl Formate Fumigation

권태형,정인홍,이병호,박정규,Kwon, Tae-Hyung,Jeong, In-Hong,Lee, Byung-Ho,Park, Chung Gyoo Korean Society of Applied Entomology 2019 한국응용곤충학회지 Vol.58 No.4

에틸포메이트는 살충 효과가 빠르고 환경에 무해하며 특히 인축독성이 낮아 검역용 훈증제로 등록되어 있다. 이러한 에틸포메이트를 이용하여 훈증 챔버 (0.275 ㎥) 내에서 4종의 농업 해충 (오이총채벌레, 담배가루이, 복숭아혹진딧물, 점박이응애)과 4종의 작물 (참외, 오이, 토마토, 고추) 유묘기를 대상으로 12시간 훈증 처리하여 약효와 약해를 평가하였다. 에틸포메이트 1.5 g/㎥의 약량으로 12시간 훈증 했을 때 담배가루이와 복숭아혹진딧물은 93.3% 이상의 높은 살충력를 나타내었으나, 점박이응애는 2.0 g/㎥ 약량에서도 20% 미만의 낮은 살충력을 나타내었다. 그리고 에틸포메이트의 CT값(농도×시간)이 훈증 처리 온도 20 ± 1.5℃에서 8.9 g·h/㎥ 이상일 때 점박이응애를 제외한 나머지 3종의 해충에 대해서 90% 이상의 살충 효과를 얻을 수 있었다. 에틸포메이트 1.5 g/㎥의 약량으로 상기 4작물을 12시간 훈증했을 때 약해 증상은 나타나지 않았다. 따라서 에틸포메이트 훈증기술은 시설 내 해충방제를 위한 새로운 방식이 될 수 있으며 관행적인 살충제의 사용을 줄일 수 있을 것으로 생각된다. 그러나 해충의 충태별, 작물의 생육 시기별 에틸포메이트 약효 및 약해에 대한 많은 연구가 이루어져야 할 것으로 생각된다. Ethyl formate (EF) is a rapid kill, environmentally safe, and low mammalian toxicity fumigant, registered to disinfest quarantine insect pests from imported agricultural products. A new concept for controlling insect pests of agricultural crops was tested in a fumigation chamber with EF. Control efficacy of and phyto-toxicity due to EF fumigation were evaluated against four pests (Thrips palmi, Bemisia tabaci, Myzus persicae, and Tetranychus urticae) and on seedlings of four fruit vegetables (FVs; yellow melon, cucumber, tomato, and pepper). Ethyl formate fumigation at a dose of 1.5 g m^-3 for 12 h produced >93.3% mortality in T. palmi, B. tabaci, and M. persicae. However, T. urticae was tolerant to fumigation, showing only 20% mortality at 2.0 g m^-3. In terms of concentration × time (CT) products, at least 8.9 g·h m^-3 CT at 20 ± 1.5℃ was needed to achieve > 90% mortality against the three susceptible insect pests. Fumigation at 1.5 g m^-3 for 12 h caused no phyto-toxicity to any of the four FV seedlings. Ethyl formate application, as a new disinfestation method in greenhouses, could be an alternative to reduce the use of conventional insecticides. However, further studies are needed to determine the efficacy of this method at different pest developmental stages and in different greenhouse environments. Additionally, research is needed to elucidate the phyto-toxicity of EF application at different growing stages of a wide variety of crops.

헛개나무열매 열수추출물 투여에 의한 흰쥐의 지구력 향상 효과

권태형,한준희,이선엽,유근형,Kwon, Tae-Hyung,Han, Joon-Hee,Lee, Sun-Yeop,Yu, Keun-Hyung 한국식품영양학회 2020 韓國食品營養學會誌 Vol.33 No.4

This study was designed to evaluate the improvement in exercise endurance by Hovenia dulcis fruit hot water extract (HDWE) for the potential application as a functional food material. The effect was based on the evaluation of the forced-swimming capacity and changes in biochemical parameters in mice. Six-week-old mice were classified into four groups based on a randomized block design: the negative control group, the HDWE 50 mg/kg body weight group, the HDWE 200 mg/kg body weight group, and the 1-octacosanol 50 mg/kg body weight group (n=8 mice per group). The swimming exercise time in the HDWE-50 group was increased at 545±43 sec compared to the control group at 263±28 sec. The HDWE-200 fatigue indicators, lactate acid and ammonia content, decreased to 4.99±0.33 mg/mL and 0.63±0.05 mg/mL, respectively. In addition, the content of glycogen in the liver and muscle tended to increase in the group administered HDWE but was not significant. Likewise, the LDH and glucose contents were increased compared to the control group. The muscle damage indicators ALT (52.7±2.6 U/L) and AST (42.5±5.2 U/L) tended to decrease compared to the control group (76.4±10.2 U/L).

열처리 시간에 따른 중적외선 투과 ZnS 세라믹의 합성과 특성

권태형,여서영,박창순,김창일,홍연우,백종후,Kwon, Tae-Hyeong,Yeo, Seo-Yeong,Park, Chang-Sun,Kim, Chang-Il,Hong, Youn-Woo,Paik, Jong-Hoo 한국센서학회 2017 센서학회지 Vol.26 No.5

In this study, a heat treatment process was applied to ZnS nano-powder to improve the optical properties of ZnS ceramic, and the characteristics of heat treatment time were studied. The ZnS nano-powders were synthesized by hydrothermal synthesis. The heat treatment was carried out at $550^{\circ}C$ for 0.5, 1, 2, and 4 hours in a vacuum atmosphere ($10^{-2}torr$). X-ray diffraction and scanning electron microscope analyzes confirmed the change of crystal phase and grain size to confirm the structural change with heat treatment time. The heat treated ZnS nano-powder was sintered by hot pressing, and the change of optical properties of the ZnS ceramic was analyzed by infrared spectroscopy.

공공사업 타당성평가에서 다기준분석의 의의와 한계

권태형(Tae-Hyeong Kwon) 한국공공관리학회 2008 한국공공관리학보 Vol.22 No.3

공공사업의 타당성을 평가하는 기법으로서 가장 널리 알려져 있는 것은 비용편익분석이나 최근에는 소위 다기준분석(Multi-criteria analysis) 의 활용이 점차 증가하고 있다. 이는 모든 편익과 비용을 화폐가치라는 단일의 척도로 전환하는 것이 현실적으로 어렵다는 인식에 근거한 것으로 판단된다. 특히 대규모 공공사업의 타당성을 사전에 검토하는 예비타당성조사에서는 계층분석적 의사결정(Analytic Hierarchy Process, ,AHP)의 활용을 기본 방법론으로 제시하고 있다. AHP 등 다기준분석 기법을 통하여 사업의 경제성에만 초점을 둔 비용편익분석의 한계를 넘어서 지역균형발전, 환경성 등 다양한 정책목표를 사업평가에 포함하고자 하는 시도에 대해서는 긍정적으로 평가를 해야 할 것이다. 하지만 AHP 평가기법을 적용하는 데에는 방법론적으로 유의해야 할 사항들이 많이 있다. 본 연구에는 예비타당성조사를 사례로 하여 AHP 기법의 적용시 유의해야 할 주요 논점들을 살펴본다. 논의에 포함된 주요 유의점은 첫째, 수치척도와 어의적 표현의 불일치 문제, 둘째, 평가척도 구간의 불균등성, 셋째, 순위역전의 문제, 넷째, 평가자별 평가기준의 동등성 문제, 다섯째, 의사결정 계층구조의 문제점 등이다. 이러한 주요 유의점에 대한 논의를 토대로 하여 예비타당성조사에서 AHP 기법 적용 방식의 개선안을 제시한다. Multi-criteria methods have been widely used for decision making in public sectors. In particular, AHP is recommended as a standard decision making method for preliminary feasibility studies of public projects. However, there has been extensive debate about the AHP in the literature with both practical and theoretical significance. This study investigates practical issues in applying AHP into preliminary feasibility studies of public projects. The issues included in this paper are numerical interpretation of the verbal scale, the assumption of a ratio scale of preference, rank reversal problems and the interpretation of criteria weights, the appropriateness of its decision hierarchy.

혼잡해소를 위한 도로건설의 정책효과: 시스템 다이내믹스 이론의 적용

권태형 ( Tae Hyeong Kwon ) 한국시스템다이내믹스학회 2011 한국시스템다이내믹스 연구 Vol.12 No.1

Congestion problems can be approached from the viewpoint of system dynamics theory. The relationship between road capacity and congestion can be explained by the ``relative control`` archetype among four system archetypes suggested by Wolstenholme. There is a balancing feedback loop between road capacity and road congestion. However, there is another balancing loop between road congestion and car traffic volume, which keeps disrupting the equilibrium of the former loop. A system dynamics model, which is based on a partial adjustment model of induced traffic in the literature, is built to simulate three road building scenarios: ``Expanding investment``, ``Balancing investment`` and ``Frozen road investment`` scenarios. The ``Expanding investment`` scenario manages to drop congestion levels by 9% over 30 years, however, causing much higher emissions of CO2 than other scenarios. The trade-off relationship between congestion levels and environmental costs must be taken into consideration for road investment policies.

상용 휘발유로부터 분리한 다환 방향족 탄화수소(PAH) 분해 세균의 특성

권태형 ( Taehyung Kwon ),우정희 ( Junghee Woo ),박년호 ( Nyunho Park ),김종식 ( Jongshik Kim ) 한국환경농학회 2015 한국환경농학회지 Vol.34 No.3

BACKGROUND: Recent studies have described the importance of bacteria that can degrade polycyclic aromatic hydrocarbons (PAHs). Here we screened bacterial isolates from commercial gasoline for PAH degraders and characterized their ability to degrade PAHs, lipids and proteins as well as their enantioselective epoxide hydrolase activity, salt tolerance, and seawater survival. METHODS AND RESULTS: One hundred two bacteria isolates from commercial gasoline were screened for PAH degraders by adding selected PAHs on to the surface of agar plates by the sublimation method. A clear zone was found only around the colonies of PAH degraders, which accounted for 13 isolates. These were identified as belonging to Bacillus sp., Brevibacterium sp., Micrococcus sp., Corynebacterium sp., Arthrobacter sp., and Gordonia sp. based on 16S rRNA sequences. Six isolates belonging to Corynebacterium sp., 3 of Micrococcus sp., Arthrobacter sp. S49, and Gordonia sp. H37 were lipid degraders. Arthrobacter sp. S49 was the only isolate showing high proteolytic activity. Among the PAH-degrading bacteria, Arthrobacter sp. S49, Brevibacterium sp. S47, Corynebacterium sp. SK20, and Gordonia sp. H37 showed enantioselective epoxide hydrolase activity with biocatalytic resolution of racemic styrene oxide. Among these, highest enantioselective hydrolysis activity was seen in Gordonia sp. H37. An intrinsic resistance to kanamycin was observed in most of the isolates and Corynebacterium sp. SK20 showed resistance to additional antibiotics such as tetracycline, ampicillin, and penicillin. CONCLUSION: Of the 13 PAH-degraders isolated from commercial gasoline, Arthrobacter sp. S49 showed the highest lipid and protein degrading activity along with high active epoxide hydrolase activity, which was the highest in Gordonia sp. H37. Our results suggest that bacteria from commercial gasoline may have the potential to degrade PAHs, lipids, and proteins, and may possess enantioselective epoxide hydrolase activity, high salt tolerance, and growth potential in seawater.

시스템 원형을 활용한 시스템 다이내믹스 모형 구축: 대체연료차량 시장 모형의 예

권태형 ( Tae Hyeong Kwon ) 한국시스템다이내믹스학회 2008 한국시스템다이내믹스 연구 Vol.9 No.2

일반논문 : 후쿠시마 원전사고와 국내 원자력정책의 변화: 정책옹호연합모형의 적용

권태형 ( Tae Hyeong Kwon ),전영준 ( Yeong Jun Jun ) 서울대학교 한국행정연구소 2015 行政論叢 Vol.53 No.4

본 연구는 정책옹호연합모형 (Advocacy Coalition Framework)을 적용하여 후쿠시마 원전사고 이후 국내 원전 정책의 변화를 분석하였다. 즉 후쿠시마 원전사고라는 외부적 충격이 원전정책에 어떻게 영향을 미치었는가를 옹호연합 내 주요 구성원의 신념체계의 변동을 중심으로 고찰하였다. 연구에 따르면, 후쿠시마 원전사고로 인한 원전 안전에 대한 불안감 증대는 원전반대의 국민여론을 확대하는 계기가 되었을 뿐만 아니라, 원전찬성연합과 원전반대연합 주요 구성원들의 신념체계에 영향을 주었다. 지배연합인 원전찬성연합의 경우, 연합의 결속력이 일시적으로 느슨해지고 일부 구성원이 원전반대연합으로 이탈하기도 하였지만, 다시 결속력이 강화된 것으로 나타났다. 또 후쿠시마 원전사고는 원전반대연합의 반대활동을 전반적으로 촉발시키는 계기가 되었고 연합의 세력도 확대되었다. 현재 다소의 정책변화에도 불구하고 전반적으로 국내의 원전확대정책은 유지되고 있으나, 찬반 논의는 다양한 장에서 더욱 활발히 전개되고 있다. This study applies the Advocacy Coalition Framework (ACF) for the case of nuclear energy policy in South Korea since the 2011 Fukushima nuclear accident. External shocks like the Fukushima nuclear accident can cause policy changes in a short period. In fact, many countries, including Germany, decided to accelerate phasing out nuclear power following the accident. However, there seems to have been little change in nuclear energy policy in South Korea even after the Fukushima nuclear accident. This study explores the nuclear energy policy subsystem to explain the stability of nuclear energy policy in South Korea. The Fukusima accident caused a temporary loosening of unity in the pro-nuclear power coalition, the dominant coalition. The Fukushima nuclear accident also triggered the political activities of the anti-nuclear power coalition. However, the policy belief of key actors in the pro-nuclear power coalition remained unchanged and that was the key reason for the stability of nuclear power policy in South Korea.