• Journal of Life Science
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• v.8 no.3
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• pp.299-304
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• 1998

In order to clarify the effects of acid rain on soil microorganisms, the inpact of acid to soil microorganisms was survyed for 14 weeks using soil microcosms from industrial site A and B, Gaejok mountain, and Daechong lake in Taejeon area. The acid tolerant-microorganisms in natural soil, using culturing method were counted to be 5.8 - $8.0{\times}10^6$CFU/g soil. The number of microorganisms using ATP-biomass analysis for natural soil samples were also analyzed and 2.2 - $2.6{\times}10^9$ cell/g soil in industrial site A and B, Gaejok mountain, and Daechong lake were determined. In soil samples, which were treated with artificial acid rain, the number of acid tolerant microorganisms were counted 2.9 - $5.8{\times}10^5$ and 2.8 - $7.5{\times}10^8$, respectively. Therefore, we conformed that the numver of soil microorganisms were influenced by acid rain. Also, long term acid tolerant microorganisms were identified as Rhodotorula sp. and Pseudomonas sp.

• Journal of Soil and Groundwater Environment
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• v.17 no.3
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• pp.49-58
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• 2012

Batch experiments using indigenous and commercialized adventive microorganisms were performed to investigate the feasibility of the biodegradation process for the diesel contaminated soil, which was taken in US Military Camp 'Hialeah', Korea. TPH concentration of the soil was determined as 3,819 mg/kg. Four indigenous microorganisms having high TPH degradation activity were isolated from the soil and by 16S rRNA gene sequence analysis, they were identified as Arthrobacter sp., Burkholderia sp., Cupriavidus sp. and Bacillus sp.. Two kinds of commercialized solutions cultured with adventive microorganisms were also used for the experiments. Various biodegradation conditions such as the amount of microorganism, water content and the temperature were applied to decide the optimal bioavailability condition in the experiments. In the case of soils without additional microorganisms (on the natural attenuation condition), 35% of initial TPH was removed from the soil by inhabitant microorganisms in soil for 30 days. When the commercialized microorganism cultured solutions were added into the soil, their average TPH removal efficiencies were 64%, and 54%, respectively, which were higher than that without additional microorganisms. When indigenous microorganisms isolated from the contaminated soil were added into the soil, TPH removal efficiency increased up to 95% (for Bacillus sp.). According to the calculation of the average biodegradation rates for Bacillus sp., the remediation goal (87% of the removal efficiency: 500 mg/kg) for the soil would reach within 24 days. Results suggested that TPH removal efficiency of biodegradation by injecting indigenous microorganisms is better than those by injecting commercialized adventive microorganisms and only by using the natural attenuation.

• Toxicological Research
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• v.27 no.4
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• pp.241-246
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• 2011

To obtain soil microorganisms producing antimigratory activity which is important in controlling the metastasis of cancer cells, more than three hundreds of soil microbes were isolated from sixteen soil sources including Namsan mountain and designated as DGU1001-10338. At first, their antibiotic activities were examined by paper-disc method. More than 40 soil microbes produced compounds with antibiotic activity. Then, antimigratory activities of selected soil microorganisms were examined in a sphingosylphosphorylcholine-induced migration assay in PANC-1 cells. Six of 42 soil microorganisms having antibacterial activity also had more than 45% inhibitory activity on migration of PANC-1 cells. These results suggested that selected soil microorganisms were a useful starting point to find compounds for controlling metastasis of cancer cells.

• The Korean Journal of Ecology
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• v.12 no.2
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• pp.67-73
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• 1989

The action and growth of soil microorganisms were studied in accordance with the leachates from leaf litter over the time lapse, and soil properties and species compositions in studied area were investigated. The investigations of soil microorganisms were made through dividing into two groupsbacterial and fungal groups. The abundance of soil microorganisms showed high correlation with organic matter(0.98) and total nitrogen(0.97) of soil. The amount of soil microorganisms was found the highest in litter layer and the next were humus and A layer in order. The bacterial growth rate in leachates from leaf letter was increased continuously by two weeks. The fungal growth rate was increased only for one week and after then it was decreased abruptly.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.110.3-111
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• 2003

The effect of biological control on the severity of hot pepper wilt disease was evaluated in the vinyl house with plants cultivated in the nursery soil containing chitin and chitinolytic microorganisms. The chitinolytic microorganisms, Trichoderma harzianum and Chromobacterium sp. strain C-61, were well survived in the nursery soil containing chitin. The hot pepper damping-off was markedly suppressed in the nursery soil containing chitin and chitinolytic microorganisms. The survival of chitinolytic microorganisms and suppression of damping-off were superior as the amounts of chitin added to the nursery soil increased, but growth of hot pepper was inhibited in the 10％ (w/w) chitin treatment. When the plants cultivated in the nursery soil containing 1％ chitin and chitinolytic microorganisms were transplanted in the vinyl house, the vegetative growth increased and the wilt disease was reduced as comparison with those of control.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.110.2-110
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• 2003

The effect of biological control on the severity of hot pepper wilt disease was evaluated in the vinyl house with plants cultivated in the nursery soil containing chitin and chitinolytic microorganisms. The chitinolytic microorganisms, Trichoderma harzianum and Chromobacterium sp. strain C-61, were well survived in the nursery soil containing chitin. The hot pepper damping-off was markedly suppressed in the nursery soil containing chitin and chitinolytic microorganisms. The survival of chitinolytic microorganisms and suppression of damping-off were superior as the amounts of chitin added to the nursery soil increased, but growth of hot pepper was inhibited in the 10％ (w/w) chitin treatment. When the plants cultivated in the nursery soil containing 1％ chitin and chitinolytic microorganisms were transplanted in the vinyl house, the vegetative growth increased and the wilt disease was reduced as comparison with those of control.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.152-157
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• 2003

Diesel-contaminated soils were ozonated for different times (0 - 900 min) and incubated for 9 wk to monitor petroleum hydrocarbons (PH)-degradative potential of indigenous microorganisms in the soils. Increased ozonation time decreased not only concentration of PH but also number of microorganisms in the soils. Microorganisms in the ozonated soils increased during 9-wk incubation as monitored by culture- and nonculture-based methods. Higher (1-2 orders of magnitude) cell number was observed by quantitative analysis of soil DNA using probes detecting genes encoding 165 rRNA(rrn), naphthalene dioxygenase (nahA), toluene dioxygenase (todC), and alkane hydroxylase (alkB) than microbial abundance estimated by culture-based methods. Such PH-degraders were relatively a few or under detection limit in 900-min ozonated soil. Further PH-removal observed during the incubation period supported the presence of PH-degraders in ozonated soils. Highest reduction (25.4%) of total PH (TPH) was observed in 180-min ozonated soil white negligible reduction was shown in 900-min ozonated soil during the period, resulting in lowest TPH-concentration in 180-min ozonated soil among the ozonated soils. Microbial community composition in 9-wk incubated soils revealed slight difference between 900-min ozonated and unozonated soils as analyzed by whole cell hybridization using group-specific rRNA-targeted oligonucleotides. Results of this study suggest that appropriate ozonation and subsequent biodegradation by indigenous microorganisms may be a cost-effective and successful remediation strategy for PH-contaminated soils.

• Journal of Life Science
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• v.12 no.5
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• pp.515-522
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• 2002

Effect of the microbial product, which consisted of Bacillus coagulans DL-1 and rice bran, on the microorganisms in soil and growth of cabbage and tomato was investigated. Bacillus congulans DL-1 was isolated form the soil and identified in this study. Total number of microorganisms in the soil treated with the microbial product was higher than the untreated soil. The growth of cabbage and tomato on the soil treated with microbial product was faster than that on the untreated soil. The treatment of microbial product in the soil resulted in the increase of useful microorganisms, which seemed to enhance the growth of cabbage and tomato. It seemed that microbial product can increase the number of certain microorganisms and change the ratio of different species of microorganisms.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.119-122
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• 2006

In both untreated and conventionally stabilized swine manures antibiotic resistant (AR) microorganisms, Staphylococcus-like and Salmonella-like microorganisms were detected. Also pathogens with MAR phynotype were detected. Presence of such microorganisms suggest high level of pathogen-related health risk to farmers who may be in direct contact with the manure and its conventionally stabilized product In contrast the autothermal thermophilic aerobic digestion (ATAD) treatment have efficiently reduced AR and pathogenicity from the swine manure. When soil was fertilized using swine manure and its stabilized products, despite no detection of MAR-exhibiting pathogen-like microorganisms in fertilized soil, potential pathogen-related health risk could not be ruled out from the fertilized soil since the organic fertilization led to increase in AR and pathogenicity in the soil microbial communities. As conclusion, this microbiological study demonstrated that an ATAD process is applicable in control of pathogen-related health risk in livestock manure.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.187-192
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• 2010

In order to monitor the possibility of horizontal gene transfer between transgenic rice and microorganisms in a paddy rice field, the gene flow from a bifunctional fusion (TPSP) rice containing trehalose-6-phosphate synthase and phosphatase to microorganisms in soils was investigated. The soil samples collected from the paddy rice field during June 2004 to March 2006 were investigated by multiplex PCR, Southern hybridization, and amplified fragment length polymorphism (AFLP). The TPSP gene from soil genomic DNAs was not detected by PCR. Soil genomic DNAs did not show homologies on the Southern blotting data, indicating that gene transfer did not occur during the last two years in the paddy rice field. In addition, the AFLP band patterns produced by soil genomic DNAs from both transgenic and non-transgenic rice fields appeared similar to each other when analyzed by the NTSYSpc program. Thus, these data suggest that transgenic rice does not give a significant impact on the communities of soil microorganisms, although long-term observation may be needed.