• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.855-864
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• 2009

The effect of toxicant on the inhibition of nitrification was investigated, using concentrated nitrifying bacteria of both attached and suspended growth. This nitrifying organism was originally obtained from the activated sludge of sewage treatment plant and cultivated for more than three months. The object of this experiment is to determine the effect of the specific surface area and the growth condition of nitrifying bacteria on toxicity of heavy metal. The results of this study were as follows. The specific surface area of both attached and suspended growth of nitrifying organism was proven to be a major factors in determining the inhibition of nitrification of heavy metal such as $Cu^{++}$ion. When the condition of attachment and detachment was compared in an experiment using attached growth nitrifier, the effect on toxicant was 1.12 times less in attached condition than in detached condition for Nitrosomonas, and 1.09 times less for Nitrobacter. In case of suspended growth nitrifier, the effect on toxicant was 1.46 times less in non-ground condition than in ground condition for Nitrosomonas, and 1.35 times less for Nitrobacter. Also, similar results were obtained in a set of experiments, without adding nitrite to the substrate. In an experiment that compared attached condition using attached growth nitrifier with detached condition using attached growth nitrifier, the effect on toxicant was 1.83 times less in attached condition than in detached one for Nitrosomonas, and 1.78 times less for Nitrobacter. In case of suspended growth nitrifier, the effect on toxicant was 1.27 times less in non-ground condition than in ground condition for Nitrosomonas, and 1.32 times less for Nitrobacter.

• The Microorganisms and Industry
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• v.17 no.1
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• pp.38-50
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• 1991

Flow cytometer(유식세포분석분리기:FCM)는 부유되어 있는 세포의 여러 특성을 측정할 수 있도록 고안되었기 때문에 동물의 체내에 있는 세포중 자연적으로 부유되어 있는 혈구세포를 분석하기가 가장 용이하다. 면역계에서 가장 중추적인 역할을 담당하며 면역반응에 특이성과 기억능력 등을 부여하는 림프구와 탐색작용을 가장 왕성히 나타내는 과립구나 단구 등이 혈액내에 존재하기 때문에 FCM을 이용하여 개체의 방어기능을 맡고 있는 면역세포를 분석하는 일이 가장 먼저 활발히 이루어졌음은 당연하였다. 도한 1970년대 면역학이 큰 발전에 이룩한 단크론항체가 Miller와 Kohler에 의하여 개발되었기 때문에 면역세포의 분화항원에 대한 여러 종류의 단크론항체는 FCM의 이용으로 면역세포를 여러 아형으로 분석하고 분리가 가능하게 하였다. 마지막으로 FCM이 최근에 개발된 것에 맞추어 세포성 면역학이 30년 전부터 급속도로 연구되었으므로 면역학적 연구가 FCM의 이용으로 더욱 활성화되었음은 주지의 사실이다. 이런 시점에서 저자는 FCM의 원리와 면역생물학에서의 FCM의 역할에 대하여 간단히 소개하려고 한다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2005.11a
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• pp.545-547
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• 2005

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1204-1210
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• 2014

New control methods are proposed for indoor air quality by removing fine airborne dust-particles. As suspended fine dust-particles contain inorganic dust as well as fine organic bacteria, studies for simultaneous control of these contaminants are required. In this study, photocatalytic disinfection of indoor suspended microorganisms such as E. coli and Bacillus subtilis is performed by three types of photocatalysts with UVA irradiation. The UVA irradiation strength was controlled to the minimum $3{\mu}W/cm^2$, and ZnO, $TiO_2$, and ZnO/Laponite ball were used as the catalysts. The results indicate that E. coli was removed over 80 % after about 2 hours of reaction with UVA and all three types of photocatalysts, whereas only with UVA, around 50 % E. coli removal was obtained. Among the catalysts, ZnO/Laponite composite ball was found to have similar sterilizing capacity to $TiO_2$. However, in case of B. subtilis, which has thick cell wall in its spore state, disinfection was not effective under the low UVA irradiation condition, even with the catalysts. Further studies need to figure out the optimal UVA irradiation ranges as well as photocatalysts doses to control airborne dust, to provide healthy clean air environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.505-509
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• 2002

남해 중부해역에서 적조발생과 관련해서 적조 다발월인 여름과 초가을에 기온과 마찬가지로 높은 수온을 유지한다. 또한 많은 강수량에 의하여 부유물질 및 영양염류가 증가하고 염분이 대체로 떨어지는 것을 알 수 있었다. 이때 적조의 bloom으로 인하여 대표적인 영양염류인 질소와 인의 값이 떨어진다. 그리고 적조생물의 사후 미생물 분해 작용이 활발하여 산소의 소모가 증가하여 용존산소가 급격히 떨어지고 화학적산소요구량이 높게 나타나는 것을 알 수 있었다. 즉, 해양인자와의 상관성은 적조의 발생조건인 수온이 적당하며 저염분과 부유물질, 클로로필, 질소, 인이 높게 나타났고 용존산소는 적조생물의 인해 낮게 나타났음을 알수 있었다.

• KSBB Journal
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• v.16 no.3
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• pp.225-232
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• 2001

The hydrophobicity of the microbial cell surface is responsible for the various interactions between microorganisms and different surface, and results in the flocculation of microbial cells, their adhesion to liquid or solid materials, and the floatation of microorganisms at the air-water interface. Accordingly, cell surface hydrophobicity is important not only in medicine but in other areas of biotechnology. This article reviews the role of cell surface hydrophobicity and its applications.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.532-535
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• 2000

Optical microscope, SEM and fluorescent microscope were used for qualitative and morphological studies of the attachment bacteria on PE substratum under anaerobic condition. The observation of optical microscopic has demonstrated that the initial attachment of bacteria began in crevices of surface. In SEM photographs, shape and structure of biofilm could be observed, but bacteria species and methanogens was not identified. A large number of methanogenic bacteria were showed on the surface of PE substratum by fluorescence under 480nm of radiation. It was estimated that methanogenic bacteria was related to initial attachment of bacteria under anaerobic condition.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.1
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• pp.189-196
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• 1991

The objective of this study was to investigate the effect of temperature on microbial characteristics and treatment efficiency in aerated submerged biofilm process. From the results of the research, conclusions were derived as following: 1. Biofilm density, attached biomass and biofilm thickness were $30-42mg/cm^3$, $1.2-2.7mg/cm^2$ and $380-690{\mu}m$, respectively. These were greatly affected by the variation of temperature ($5-20^{\circ}C$) and packing ratio(45-90%). 2. The ratio of suspended biomass to the total biomass in the reactor was in the range of 10 to 50 % in accordance with the variation of temperature and packing ratio. Therefore, the portion of suspended biomass cannot be neglected. 3. BOD removal efficiency increased as either temperature or biomass(suspended and attached) concentration increased. 4. The aerated submerged biofilm process appeared to be less affected by temperature variation and the estimated temperature correction coefficient of the Van't Hoff-Arrhenenius equation was 1.042.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.369-371
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• 2008

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.497-498
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• 2004