• Biotechnology and Bioprocess Engineering:BBE
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• 제5권6호
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• pp.465-468
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• 2000

Methyl mercaptan oxidase was successfully induced from Rhodococcus rhodochrous IGTS8 using methyl mercaptan gas and purified to homogeneity for the detection of mercaptans. The purification procedure involved DEAE-Sephacel and Superose 12 column chromatography with recovery yields of 85.8 and 83.3%, and a specific activity of 92.7 and 303.4 units/mg-protein, respectively. The molecular weight of purified methyl mercaptan oxidase was determined to be 64.5 kDa by SDS-PAGE. The extract from gel filtration chromatography oxidizes methyl mercaptan to produce formaldehyde, which can be easily detected by the purpald-coloring method. Optimum temperature for activity was achieved at 60$^{\circ}C$. This enzyme was inhibited by both K$_2$SO$_4$and NaCl at concentration of less than 100mM and recovered to original activity at concentration of 200mM. In the presence of methanol, the activity decreased by 33%.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권6호
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• pp.375-379
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• 2002

Methyl mercaptan oxidase was successfully induced in Thiobacillus thioparus TK-m using methyl mercaptan gas, and was purified for the detection of mercaptans. The purification procedure Involved a DEAE (diethylaminoethyl) -Sephacel, or Superose 12, column chromatography with recovery yields of 47.5 and 48.5%, and specific activities of 374 and 1240.8 units/mg-protein, respectively, The molecular weight of the purified methyl mercaptan oxidase was 66.1kDa, as determined by SDS-PAGE. The extract, from gel filtration chromatography oxidizes methyl mercaptan, producing formaldehyde, which can be easily detected by the purpald-coloring method. The optimized temperature for activity was found to be at 55$\^{C}$. This enzyme was inhibited by both NH$_4$Cl and (NH$_4$)$_2$SO$_4$, but was unaffected by either KCl or NaCl at less than 200 mM. With K$_2$SO$_4$, the activity decreased at 20 mM, but recovered at 150 mM. In the presence of methanol, full activity was maintained, but decreased in the presence of glycerin, ethanol and acetone 43, 78 and 75%, respectively.

• 한국결정성장학회지
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• 제20권5호
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• pp.221-226
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• 2010

메칠멜캅탄($CH_3SH$) 가스를 검출하는 수정진동자(QCM) 가스센서를 QCM의 전극에 $TiO_2$ 나노입자와 전해질 폴리머를 증착하여 제조하였다. LBL-SA법에 의해 제조된 $TiO_2$/PSS 박막은 높은 비표면적을 나타내었고, 가스센서의 감도를 증가시켰다. 1.0 ppm의 농도를 갖는 메칠멜캅탄에 노출된 TEA 혹은 $TiO_2$/PSS 막이 증착된 QCM의 주파수 변이는 각각 약 9 Hz, 2 Hz 였다. ($TiO_2$/PSS) 박막의 증착수가 늘어남에 따라 제조된 박막의 비표면적이 증가하게 되어 QCM 센서의 주파수 변이도 점차적으로 증가하였다. 추가적으로 메칠멜캅탄 가스의 농도가 0.5 ppm에서 2.0 ppm으로 높아짐에 따라 QCM 센서의 주파수 변화도 증가되었다. 본 연구에서는, ($TiO_2$/PSS) 박막이 증착된 QCM 센서의 표면구조의 변화와 센서 특성을 측정하였다.

• 한국치위생학회지
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• 제11권2호
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• pp.263-275
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• 2011

Objectives : This study was performed analysis of Halitosis components following by subjective cognition of halitosis and Oral State in order to provide basic data for halitosis prevention and establish a device to efficiently eliminate halitosis and analyze the factors that affect the halitosis. Methods : 80 adults were participated who visited at the Dental Clinic in Kyoung-gi do, on the period of the March to September in 2010. The obtained results, through the oral examination, halitosis check and interview, Individually, were as followings. Results : According to the ammonia level was a high relationship between sex, CPI, Tongue plaque, DMFT index which were statistically significant (p<0.05). Total oral gas level was a relationship between VAS, tongue plaque, DMFT index(p<0.05). The Correlation coefficient between the Hydrogen sulfide level and Methyl mercaptan was estimated as r=0.534(p<0.01). As for the multiple regression analysis result, there have been selected dimethyl sulfide and Tongue plaque, Gingival index as factors affecting Bridge, Methyl mercaptan level is as factors affecting Hydrogen sulfide level. Conclusions : There was relationship between the periodontal disease and Ammonia gas component, hydrogen sulfide, dimethyl sulfide, methyl mercaptan. Which were statistically significant total oral gas level and oral variables. Such dental caries as the prevention or early treatment of periodontal disease.

• Journal of Korean Society for Atmospheric Environment
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• 제18권E3호
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• pp.165-174
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• 2002

A dual -column biofilter system with two different composts was used to investigate the macro-kinetics of dim-ethyl disulfide (DMDS) degradation. The biofilter columns were filled with compost mixtures up to one meter, The gas How rate and DMDS concentration to the biofilters were varied to study their effect on the removal characteris-tics of DMDS. It was found that the biodegradation of DMDS was governed by zero-order reaction -limited macro-kinetics for inlet DMDS concentrations between 10 and 55 ppmv. The overall average zero-order kinetic coeffi-cient for DMDS removal by compost was 0.50 ($\pm$0.1) ppm/sec for both compost mixtures studied. Variations in individual kinetic coefficients were observed due to varying environmental conditions, such as pH and temperature. The kinetic coefficients determined are specific to the system discussed in this work. During high acidity conditions in the filter beds, methyl mercaptan (MM) was observed in the gas samples collected. Appearance of MM was pro-bably due to decreased microbial activity in the lower portions of the biofilter. Considering the neutral pH range required and the presence of methyl mercaptan, it is likely that the microorganisms present in the biofilters used in this research are similar to the T. thioparus (strain E6) species.

• 한국환경과학회지
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• 제16권1호
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• pp.33-38
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• 2007

The concentrations of offensive odorous compounds emitted from the two chemical plants in Chongju and Yeosu industrial complex in Korea were determined by uv/vis spectroscopy, gas chromatography, and high performance liquid chromatography. The odorous compounds examined in this study are ammonia, trimethyl amine, formaldehyde, acetaldehyde, propion aldehyde, butyl aldehyde, n-valeric aldehyde, iso-valeric aldehyde, hydrogen sulfide, methyl mercaptan, dimethyl sulfide and dimethyl disulfide. The concentrations of those were determined from the 10 sampling points of the two plants, respectively. The emission concentrations of all odorous com-pounds examined in the two plants were lower than those of the regulation standard levels of industrial complex in Korea, respectively. The propion aldehyde, n-valeric aldehyde, methyl mercaptan and dimethyl disulfide in Chongju and Yeosu plants, and butyl aldehyde and iso-valeric aldehyde in Yeosu plant were not detected at any sampling points examined.

• KSBB Journal
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• 제22권3호
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• pp.151-156
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• 2007

본 논문은 식물정유를 이용해 유해가스를 처리하는 경우에 식물정유의 주요 구성성분을 파악하고 이를 통해 처리효율을 규명하는데 연구하였다. 또한 식물정유와 메틸 멀캅탄 악취가스에 의한 메틸 멀캅탄 악취가스 제거반응 메카니즘을 규명하였으며 그 결과는 아래와 같다. 1) 악취가스 중 메틸 멀캅탄 악취가스는 식물정유 추출물과 중화반응에 의해 처리될 수 있음을 나타내었다. GC-MS분석에 의한 식물정유 추출물의 성분 중 식물정유의 화학구조는 알코올기, 케톤기, 에스터기가 관여하는 것으로 나타났다. 충전탑내 식물추출물의 순환속도의 실험결과에서 중화반응으로 메틸 멀캅탄 악취가스가 제거되는 메카니즘은 앞서 언급한 화학작용기와 메틸 멀캅탄 악취가스의 중화반응에 의해 염을 형성하여 제거되는 과정을 갖는다. 2) 메틸 멀캅탄 악취가스 제거효율은 식물정유 추출물의 희석비와 스프레이 분무속도 그리고 초기 메틸 멀캅탄 악취가스 농도 등에 따라 달라질 수가 있음을 알 수 있었다. 시험결과는 식물정유 추출물의 희석비와 스프레이 분무속도 그리고 초기 메틸 멀캅탄 악취가스 농도가 희박한 경우에 최대 98%의 제거효율을 얻을 수가 있었다.

• 한국식품과학회지
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• 제34권4호
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• pp.559-564
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• 2002

김치를 각각 다른 온도에서 일주일간 숙성시킨 후, 먼저 젖산균수와 관능성을 관찰하고 동결건조시킨 후, 동결건조에 의한 김치의 주요한 휘발성냄새성분의 변화를 관찰하였다. 김치의 숙성온도를 증가시킴에 따라 시료의 pH는 저하하였고 $25^{\circ}C$의 경우를 제외하고는 젖산균수는 증가하였으며, 관능적 특성은 $0^{\circ}C$의 경우는 표준시료와 차이가 없었으나, $5^{\circ}C$, $15^{\circ}C$, $25^{\circ}C$의 관능적 특성은 숙성온도가 증가함에 따라 점차 저하하였다. 본 실험에서 검출된 김치의 휘발성냄새성분은 allyl mercaptan, methyl allyl sulfide, dimethyl disulfide, diallyl sulfide, diallyl disulfide와 같은 황함유성분 5종과 ethanol이며, 이 중에서 allyl mercaptan, methyl allyl sulfide, diallyl sulfide, ethanol은 시료에 따라 차이는 있었으나 김치의 숙성온도가 증가함에 따라 생성량이 증가하였고, dimethyl disulfide와 diallyl disulfide는 숙성온도가 증가함에 따라 감소하였다. 한편 24시간 동결건조의 경우는 이상의 모든 휘발성 냄새성분이 현저하게 감소하였으며 48시간 동결건조에 의하여 시료에 따라서는 24시간과 거의 같거나 24시간보다 더 감소하였다.

• 환경위생공학
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• 제22권2호
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• pp.35-40
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• 2007

It disposes positively in the air pollution damage which is serious, in order help period the place where it improves the quality of existence and life of the local residents. It removed the offensive odor regulation material and the technique it will be able to prevent to sleep it researched it did. After scattering the GNC solution which develops the offensive odor regulation material which occurs from the food and trash treatment plant which is located to the S from the H, company after scattering the GNC solution which it develops collection it did a control criminal record control kind air and it analyzed. In this study, we investigated the emission concentrations of offensive odorous compounds of hydrogen sulfide, methyl mercaptan, dimethyl sulfide and dimethyl disulfide, trimethylamine, formaldehyde, acetaldehyde, propionaldehyde, buthylaldehyde, iso-valeric aldehyde, n-valeric aldehyde, ammonia. The concentrations of odorous compounds are determined by gas chromatography, HPLC and uv-vis spectroscopy. Hydrogen sulfide, methyl mercaptan, dimethyl sulfide and dimethyl disulfide were not detected at any point examined.

• 대한환경공학회지
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• 제34권8호
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• pp.541-548
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• 2012

본 연구에서는 생활폐기물 자동집하시설에서의 악취물질 배출특성을 파악하고자 2개소(A시설, B시설)의 시설을 선정하여 공기관로 내의 이송가스와 최종배출가스를 대상으로 복합악취와 22종의 지정악취물질을 조사하였다. 생활폐기물 자동집하시설에서 배출되는 주된 악취물질은 암모니아, 황 화합물, 아세트알데하이드이었으며, 악취처리공정의 종류에 따라 최종배출구의 악취 배출특성이 상이하였다. 이송가스를 대상으로 한 악취기여도 평가에서는 A시설의 경우, 디메틸설파이드 26%, 아세트알데하이드 18%, 메틸머캅탄 14%의 악취기여도를 보였으며, B시설의 경우에는 메틸머캅탄 56%, 황화수소와 디메틸설파이드가 각각 15%이었다.