• Journal of Microbiology
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• 제39권2호
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• pp.83-88
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• 2001

There is considerable interest in how microbiological processes can affect the behaviour of metal contaminants in natural and engineered environments and their potential for bioremediation. The extent to which microorganisms can affect metal contaminants is dependent on the identity and chemical form of the metal and the physical and chemical nature of the contaminated site or substance. In general terms, microbial processes which solubilize metals increase their bioavailability and potential toxicity, whereas those that immobilize them reduce bioavailability. The balance between mobilization and immobilization varies depending on the metal, the organisms, their environment and physico-chemical conditions.

• 한국환경보건학회지
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• 제38권3호
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• pp.213-222
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• 2012

Objectives: This study was undertaken in order to evaluate by work space zoning and structure the concentrations of biological contaminants in the indoor air of domestic office buildings. Methods: Air samples were collected in the office spaces of 15 office buildings in Seoul from June 28 to July 28, 2011. Prior to the sampling, each office was classified into 'open-plan office', 'cellular office' and 'mixed office' according to the work space zoning. To evaluate the biological contamination of indoor air, total suspended bacteria (TSB), Gram positive bacteria (GPB), Staphylococcus aureus (S.A), Methicillin-resistant Staphylococcus aureus (MRSA), Gram negative bacteria (GNB) and fungi were investigated. During the sampling, temperature, relative humidity and carbon dioxide ($CO_2$) were measured. Results: The TSB concentrations ($GM{\pm}GSD$) were $452({\pm}1.3)cfu/m^3$ in open-plan offices, $366({\pm}1.3)cfu/m^3$ in cellular offices and $287({\pm}1.5)cfu/m^3$ in mixed offices, and there were significant differences between the three groups (p<0.05). The highest concentrations ($GM{\pm}GSD$) of fungi were found in the indoor air of cellular offices $128({\pm}1.0)cfu/m^3$, which was at least three times higher than the concentrations in mixed offices $43({\pm}1.0)cfu/m^3$ (p<0.05). Conclusions: Microbiological contamination in the indoor air of office buildings by work space structure was the highest with the open-plan office layout which includes no high walls or doors separating the occupants.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.164-167
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• 2004

To investigate the chemical and microbiological characteristics of groundwater and surface waters in contaminated sites, hydrochemical and microbial community analysis were executed. Different indigenous bacteria were observed at 4 contaminated sites and this is considered to decompose the contaminants of groundwater. The research results showed the close relationship between hydrochemistry and microbial characteristics and those are used for the information of natural attenuation and enhanced bioremediation.

• Journal of Microbiology
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• 제35권4호
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• pp.354-359
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• 1997

Methods for the extraction of DNA from water sample were approximated. Four different procedures of DNA extraction were carried out with pellets obtained from centrifugation of 4 liter water samples. The recovery efficiency and purity of DNA extracted by each method from different sources were compared. DNA yield varied with extraction methods, Method I, which involves enzymatic and freeze-thaw lysis steps and phenol and phenol-chloroform purification of extracted nucleic acid, showed a significantly higher yield and purity than the other methods. The use of glass beads in the DNA extraction methods improved the purity of DNA suitable for PCR. Bovine serum albumin in the PCR reaction mixture was useful in reducing inhibitory effects of contaminants. The efficiency of an extraction method was determined by the detection of the aer of Aeromonas hydrophila with PCR. The lower limit of detection of A. hydrophila from seeded tap water was 2 CFU/ml in PCR when method I was used for DNA preparation.

• Journal of Microbiology
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• 제35권1호
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• pp.66-71
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• 1997

To investigate the biodegrading capability of several white-rot fungi isolated in Korea, biodegradation of BTX (benzene, toluene, xylene), phenanthrene and pyrene were tested in fungal cultures. Phanerochaete chrysosporium removed 20-30% of BTX mixture during 21 days of incubation in serum bottle. Coriolus versicolor KR-11W and Irpex lacteus mineralized 10.02 and 8.26% of totla phenanthrene, respectively, which were higher than in other studies with P. chrysosporium. These two strains also showed high mineralization rates (9.2-10.1%) for 4-ring pyrene. I. lacteus metabolized most of the added pyrene and 23.29% was incorporate dinto fungal biomass. Almost 50/5 of the pyrene was converted to polar metabolites and recovered from aqueous phase of culture. These results indicated that some white- rot fungi have higher biodegradability than P. chrysosporium and could be used in bioremediation of aromatic hydrocarbon contaminants in soil.

• Environmental Engineering Research
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• 제24권3호
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• pp.418-426
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• 2019

Current available commercial membranes are not robust and are therefore destroyed if left to dry out or handled roughly. Woven fibre microfiltration (WFMF) membranes have advantages over its competitors with respect to durability, thus, favourable for the developing economies and operation during rough conditions. Evaluation of the effects of aeration and brushing as a flux enhancement strategies for WFMF membrane was the purpose of this study. The WFMF membrane was found to be susceptible to pore plugging by colloidal material and adsorption/attachment by microbiological contaminants. This led to a 50% loss in flux. Aeration as a single flux enhancement strategy proved insufficient to maintain high flux successfully. Therefore combined flux enhancement strategies yielded the best results.

• 생태와환경
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• 제39권3호통권117호
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• pp.285-295
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• 2006

본 연구에서는 (1) 선진외국 및 기타국가의 농업용수 수질기준을 검토하고 (2) 선진외국과 국내의 농업용수 수질기준을 항목별로 심층 비교 분석하여, 현행 농업용수 수질기준의 적정성을 평가하였다. 또한 (3) 국내 농업용수 수질기준의 문제점을 파악하고 추가로 기준설정이 요구되는 수질기준 항목을 도출하였다. 우리나라의 농업용수 수질기준은 따로 마련되어 있는 것이 아니라, 수질환경기준의 4등급에 해당하는데, 이는 관리목적의 기준으로 이수목적의 농업용수로 필요한 항목들이 누락되어 있는 실정이다. 예를 들어 캐나다의 경우 농약과 비료에 의한 오염 등을 고려하여 관개용수 수질기준을 제시하고 있으며 일본의 경우 우리나라와 달리 EC, Zn, 그리고 Cu항목을 설정해 두고 있다. FAO에서도 주요항목으로 염도와 토양 침투율 그리고 특정이온의 독성에 대해 제시하고 있으며 중국의 경우 벼에 대한 농업용수 수질기준을 따로 제시하고 있는 실정이다. 국내 농업용수 수질기준의 추가항목 필요성은 수질환경기준의 8항목과 사람의 건강보호항목 9항목으로 나누어 세밀하게 검토한 결과, 국내 농업용수 수질기준에 추가되어야 할 수질항목으로 나트륨, 전기전도도, 미생물항목. 그리고 5개의 미량원소 (염소, 붕소, 구리, 철, 아연)가 제안되었다. 전기전도도 (EC) 는 염도의 지표로 식물뿌리 주변에 염농도가 높으면 수분결핍과 이온 독성을 나타낸다. 하수처리수를 재이용하여 농업용수로 이용할 경우 분변성 오염은 공중위생상 문제가 되며 병원성 미생물의 공존가능성을 시사하기 때문에 미생물항목이 필요하다. 또한, 염소, 붕소, 구리, 철, 아연의 5개의 원소는 이미 선진국에서는 기준설정이 되어 있는 수질항목들로, 식물생장에 필수원소들이지만 일정량 이상이 되면 식물독성을 유발하는 원소로 제시되었다. 우리나라의 농업용수 수질기준이 농작물을 보호하고, 나아가 인체건강을 고려하는 실질적인 이수목적의 기준이 되기 위해서는 추가로 제안된 수질항목들에 대한 기준이 선정된 필요가 있는 것으로 사료된다.

• Journal of Microbiology
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• 제44권1호
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• pp.42-49
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• 2006

In this study, we describe our newly-developed sensitive two-stage PCR procedure for the detection of 13 common mycoplasmal contaminants (M. arthritidis, M. bovis, M. fermentans, M. genitalium, M. hominis, M. hyorhinis, M. neurolyticum, M. orale, M. pirum, M. pneumoniae, M. pulmonis, M. salivarium, U. urealyticum). For primary amplification, the DNA regions encompassing the 16S and 23S rRNA genes of 13 species were targeted using general mycoplasma primers. The primary PCR products were then subjected to secondary nested PCR, using two different primer pair sets, designed via the multiple alignment of nucleotide sequences obtained from the 13 mycoplasmal species. The nested PCR, which generated DNA fragments of 165-353 bp, was found to be able to detect 1-2 copies of the target DNA, and evidenced no cross-reactivity with the generated DNA of related microorganisms or of human cell lines, thereby confirming the sensitivity and specificity of the primers used. The identification of contaminated species was' achieved via the performance of restriction fragment length polymorphism (RFLP) coupled with Sau3AI digestion. The results obtained in this study furnish evidence suggesting that the employed assay system constitutes an effective tool for the disagnosis of mycoplasmal contamination in cell culture systems.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권6호
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• pp.101-113
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• 2016

To properly manage and remediate groundwater contaminated with chlorinated hydrocarbons such as trichloroethylene (TCE), it is necessary to assess natural attenuation processes of contaminants in the aquifer along with investigation of contamination history and aquifer characterization. This study evaluated natural attenuation processes of TCE at an industrial site in Korea by delineating hydrogeochemical characteristics along the flow path of contaminated groundwater, by calculating reaction rate constants for TCE and its degradation products, and by using geochemical and reactive transport modeling. The monitoring data showed that TCE tended to be transformed to cis-1,2-dichloroethene (cis-1,2-DCE) and further to vinyl chloride (VC) via microbial reductive dechlorination, although the degree was not too significant. According to our modeling results, the temporal and spatial distribution of the TCE plume suggested the dominant role of biodegradation in attenuation processes. This study can provide a useful method for assessing natural attenuation processes in the aquifer contaminated with chlorinated hydrocarbons and can be applied to other sites with similar hydrological, microbiological, and geochemical settings.

• 미생물학회지
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• 제1권1호
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• pp.38-44
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• 1963

According to the experiment on pure-isolation and the related contaminants of Chlorella, the phenomena of the ecological distributions of Chlorella in Korea have been manifested in several areas and also the aim that in going to do culture, biological and physiological study of Chlorella is carried out. Contaminants very oftenly occupied on the colony of the strains taken in order to fulfil pure-isolation of Chlorella, but in accordance with being piled up the minute research on this subject, I can obtain the desirable results as follows: 1. For the pure-isolation, the duration chose the time from May to September 1957 so that may easily isolate from contaminant water with utilizing the antibiotic substances. 2. To take long time, 36-48 hours until growth of nascent through the non-sporulated, it originates from the difference of the cultured media. In addition to the above mention, the mechanism of growth until nascent through the sporulated must not always require the ligh. However the supply of metabolic energy depend upon its nutritional conditions per phase. 3. The culture of Chlorella should be based on the lower culturing except adding especial conditions such as reagent concentration of media, artifical shake of media and other facts due to the natural conditions. And also these strains grew not only in distilled water but 2% NaCl solution without any abnormality in cell it self. I, therefore, guess it is possible to culture in sea-water under phasic environment. 4. In the experiment of ammonia detection, it is caused by the sampling surroundings to contain the minute quantity of ammonia in strain No. M 918; that is the place to be plenty of Carbohydrate on behalf of protein. 5. To compare the absorption curve of chlorophyll of higher plant with that of Chlorella, the absorption zone made mostly the Same ones each other but a little absorption grade dose not clearly appear. The colony which formed giant type grows with intensive colour and green band on surrounding of the colony and after that it was changed into all the green colour and developed up to end. 6. At first phase for a week, the development of Chlorella suspends the normal condition as in vivo but after a few days, the colour of chlorophyll gradually changed into blue-yellow which secrete the mucous substances on the agar media. The cell was flew out the contained substances itself on leaving the cell wall only, or the various micro-organism diffused on the outer-region of the cell.