• Journal of Microbiology
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• v.39 no.2
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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.

• Journal of Environmental Health Sciences
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• v.38 no.3
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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.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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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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• v.35 no.4
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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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• v.35 no.1
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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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• v.24 no.3
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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.

• Korean Journal of Ecology and Environment
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• v.39 no.3 s.117
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• pp.285-295
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• 2006

Korean water quality standards for the protection of agricultural water uses were originally derived based on management of public water resource. They were not prepared to protect crop plants from contaminants, and therefore required water parameters in agricultural uses were excluded in current water quality standards. Korean water standards in river and lake have five levels, and level IV is correspondent to agricultural water uses. Currently, there is no Korean guidelines to protect crop plants from contaminants contained in agricultural water. In Canada, agricultural water guidelines are provided to protect crops from contaminants. In this study, agricultural water quality standards in Korea were compared with them in developed countries to evaluate the adequacy of Korean water quality standards for the protection of agricultural water uses. Additional water quality parameters in agricultural uses were also proposed. Suggested parameters include electric conductivity, sodium, chloride, boron, copper, iron, zinc, and microbiological quality, They are the required parameters to protect crop plants as well as human health. Current water quality standards in agricultural uses was not considered to be appropriate in terms of crop protection. Additional water parameters should be included in agricultural water quality standards.

• Journal of Microbiology
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• v.44 no.1
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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.

• Journal of Soil and Groundwater Environment
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• v.21 no.6
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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.

• Korean Journal of Microbiology
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• v.1 no.1
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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.