• Journal of Soil and Groundwater Environment
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• v.19 no.3
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• pp.56-65
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• 2014

Contamination of explosive compounds in the soils of military shooting range may pose risks to human and ecosystems. As shooting ranges are located at remote places, active remediation processes with hardwares and equipments are less practical to implement than natural solutions such as bioremediaton. In this study, a series of experiments was conducted to select a suitable carbon source and to optimize dosing rate for the enhanced bioremediation of explosive compounds in surface soils and sediments of shooting ranges with indigenous microorganisms activated by external carbon source. Treatability study using slurry phase reactors showed that the presence of indigenous microbial community capable of explosive compounds degradation in the shooting range soils, and starch was a more effective carbon source than glucose and acetic acid in the removal of TNT. However, at higher starch/soil ratio, i.e., 2.0, the acute toxicity of the liquid phase increased possibly due to transformation products of TNT. RDX degradation by indigenous microorganisms was also stimulated by the addition of starch but the acute toxicity of the liquid phase decreased with the increase of starch/soil ratio. Taken together, the optimum range of starch/soil ratio for the degradation of explosive compounds without significant increase in acute toxicity was found to be 0.2 of starch/soil.

• The Plant Pathology Journal
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• v.34 no.1
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• pp.78-84
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• 2018

Peroxyacetic acid mixture Perosan, composed of peroxyacetic acid, hydrogen peroxide and acetic acid, was evaluated for eco-friendly management of tomato bacterial wilt by Ralstonia pseudosolanacearum. Perosan drastically suppressed in vitro growth of R. pseudosolanacearum in liquid cultures in dose- and incubation time-dependent manners. Higher perosan doses (0.1 and 1%) caused lowered pH and phytotoxicity to detached leaves of two tomato cultivars Cupirang and Benekia 220 in aqueous solution. Treatment with 0.01% of Perosan delayed wilting symptom significantly in the detached leaves of two cultivars inoculated with R. pseudosolanacearum ($10^7cfu/ml$). Soil drenching of 5% Perosan solution in pots caused severe tissue collapse of tomato seedlings at the four-week-old stage of two tomato cultivars. Treatment with 1% Perosan by soil-drenching significantly reduced bacterial wilt in the tomato seedlings of two cultivars. These findings suggest that Perosan treatment can be applied to suppress bacterial wilt during tomato production.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.27-37
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• 2014

Objectives: On September 27, 2012, leakage of anhydrous hydrofluoric acid occurred in a chemical plant in the Gumi National Industrial Complex. Following the accident, local factory workers and residents complained of abnormal health conditions. In addition, visual discolorations were widely observed in crops and trees in surrounding areas. The main objectives of the present study were to identify the area that was affected by the spill using data obtained from plants, soil, and water samples after the accident. Methods: Fluoride concentrations were analyzed in pine tree needles, soil, nearby streams, ponds and reservoirs collected from an area within a radius of three kilometers from the plant where the leak occurred. Fluoride concentrations in the air at the time of leakage were then estimated from fluoride concentrations that were measured in the pine tree needles. A Kriged map was developed to describe the spatial distribution of hydrofluoric acid at the time of the leakage and was compared with the area designated as a Special Disaster Zone by the government. Results: The Special Disaster Zone did not include all the affected area that was estimated by the Kriged map. Analytical results of the environmental samples also supported this discrepancy. Conclusion: Using plants, atmospheric concentrations of fluoride at the time of the leakage could be estimated. For the area that was identified as affected, further public health risk assessment and environmental risk assessment should be considered. Also, in the absence of air monitoring at the time of leakage, studies employing plants may be conducted in order to better understand the spatial extent and severity of the contamination.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.998-1003
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• 2012

Pantoea agglomerans DSM3493 was isolated from green house soils collected from Chungchugnam-do province, Gongju-Gun area in South Korea and phosphate solubilization and organic acid production of the strain were assessed using three types of insoluble phosphate sources (Ca phosphate, Fe phosphate and Al phosphate) under three different pH conditions (7, 8 and 9). The highest Ca phosphate solubilization ($651{\mu}g\;mL^{-1}$) was recorded at pH 7 followed by pH 8 and 9 (428 and $424{\mu}g\;mL^{-1}$ respectively). The solubilization rate was found to be 80.4, 98.1 and $88.7{\mu}g\;mL^{-1}$ (for Fe phosphate containing medium) and 9.3, 12.1 and $29.8{\mu}g\;mL^{-1}$ (for the Al phosphate containing medium) respectively at pH 7, 8 and 9. Though increasing pH of the medium caused reduction in the rate of solubilization of Ca phosphate, solubilization of Fe and Al phosphates enhanced with increasing pH. By contrast, the highest amount of organic acid was produced with Ca phosphate while the lowest was recorded with the presence of Al phosphate. Among the organic acids, gluconic acid production was found to be the highest, followed by oxalic acid and citric acid regardless the source of phosphate. Results can thus be concluded that the production of organic acids appears to play a significant role in the inorganic phosphate solubilization.

• Research in Plant Disease
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• v.19 no.3
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• pp.208-215
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• 2013

3-(4-Hydroxyphenyl)-propionic acid (HPP) is a bacterial metabolite synthesized and released by an entomopathogenic bacterium Xenorhabdus nematophila K1. In this study, the control efficacy of HPP was tested against Phytophthora blight and anthracnose of red pepper plants. HPP suppressed mycelial growth of Phytophthora blight and anthracnose pathogens. Under natural sunlight condition, HPP maintained the antifungal activity on the diseases for at least twenty five days. The antifungal activity was not decreased even in the condition of soil-water. It was proved that HPP was able to penetrate the roots and travel upward of the red pepper plants. When HPP suspension was applied to soil rhizosphere before transplanting the red pepper seedlings or was regularly sprayed to the foliage of the plants with ten days interval, it resulted in significant reduction of the disease occurrences (Phytophthora blight and anthracnose) without any phytotoxicity. These results suggested that HPP can be developed to a systemic agrochemical against Phytophthora blight and anthracnose of red pepper plants.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.397-401
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• 2005

Acid mine drainage and waste of abandoned mine area have caused serious water pollution and destruction of an ecosystem because of exposing to environment without an appropriate treatment. Gwang-yang mine area also has a serious problem in the nearby residential area and waterway ecosystems. The objectives of this research are to develop the most suitable remediation system for acid mine drainage by using waste materials, and to diagnose stream environments impacted by acid mine drainage through the new ecological health assessment methodology, and thus ultimately providing a restoring methodology to mining regions. In the water system health assessment, the result of ESHI model, RBP and Karr suggested by US EPA is revised by ecological features of our country, come to ESHI score 13; 'Very poor' at some points. Together with pH value and heavy metal concentration, it's the aggravation of ecological health index caused by chemical disturbances. In the acid mine drainage treatment, we apply marine shells and slags to this system. Slags had the best removal ability for heavy metals, but pH value was more than 10 exceeding the standard for drain water. In case of marine shells, pH of treated water maintained 7 to 8, and concentrations of Fe and Zn decreased significantly after treatment.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.2
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• pp.356-365
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• 1995

study was made to investigate the emulsification and rolling-up between liquid oily soils and surfactant and its effect on the detergency. Samples used were triolein as a triglyceride, oleic acid as a free fatty acid and sodium dodecyl sUJfate(SDS) as a surfactant. The results were as follows: 1. The spontaneous emulsification occurred in the system of oleic acid alone and mixture of triolein and oleic acid contacted with 0.5% SDS solution, but it did not occurred in a case of triolein alone. 2. The stability of emulsification increased with the increase of SDS concentration. And the stability of emulsification and (-) t value increased in the order of triolein < mixture of triolein and oleic and< oleic acid. 3. The rolling-up mechanism of model oily soils easily occurred in the order of triolein< mixture of triolein and oleic acid< oleic acid, and facilitated with the increase of SDS concentration. On the other hand, the complex formation was already observed in the system of oleic and 0.5% SDS solution. 4. As compared with the detergency of triolein, the detergency of oleic acid was very high. And the detergency of mixed soil was improved with increasing ratio of oleic acid in the mixture.

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.665-671
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• 1994

For the production of pyrogallot from gallic acid, about 100 strains of bacteria capable of assimilating gallic acid as a sole carbon and energy source were isolated from the soil. JH- 004 strain showing the highest activity of gallate decarboxy#lase was selected from them and identi- fied as Erwinia sp. The optimal conditions for the production of pyrogallol from gallic acid were examined. The resting cells of JH-004 cultured in a complex medium containing 0.2%(w/v) gallic acid were prepared after the treatment of the pellet with a freezing and thawing, and used as a enzyme source. The reaction mixtures for the maximal production of pyrogallol were shown to be 6 g/l of resting cells and 15 g/l of gallic acid in 25 mM potassium phosphate buffer. The optimal pH for the reaction was 5.0 and the optimal temperature was 35$\circ$C . Additionally, Triton X-100(0.01%, w/v) was found to be most effective for the production of pyrogallol. Under the above conditions, 10.27 g/l of pyrogallol was produced from 15 g/l of gallic acid after incubation of 35 hrs. This amount of pyrogallol corresponds to a 92.37% yields, based on gallic acid.

• Journal of Microbiology
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• v.38 no.2
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• pp.53-61
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• 2000

Hydroxybenzoic acids are the most important intermediates in the degradative pathways of various aromatic compounds. Microorganisms catabolize aromatic compounds by converting them to hydroxylated intermediates and then cleave the benzene nucleus with ring dioxygenases. Hydroxylation of the benzene nucleus of an aromatic compound is an essential step for the initiation and subsequent disintegration of the benzene ring. The incorporation of two hydroxyl groups is essential for the labilization of the benzene nucleus. Monohydroxybenzoic acids such as 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, and 4-hydrosybenzoic acid, opr pyrocattechuic acid that are susceptible for subsequent oxygenative cleavage of the benzene ring. These terminal aromatic intermediates are further degraded to cellular components through ortho-and/or meta-cleavage pathways and finally lead to the formation of constituents of the TCA cycle. Many groups of microorganisms have been isolated as degraders of hydroxybenzoic acids with diverse drgradative routes and specific enzymes involved in their metabolic pahtway. Various microorganisms carry out unusual non-oxidative decarboxylation of aromatic acids and convert them to respective phenols which have been documented. Futher, Pseudomonas and Bacillus spp. are the most ubiquitous microorganisms, being the principal components of microflora of most soil and water enviroments.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.500-505
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• 2014

In recent years, organic ginseng cultivation has increased because customers prefer organic ginseng products due to the morphological quality as well as the safety such as the residuals of chemically-synthesized pesticides. Therefore, some of paddy and upland fields were converted into organic ginseng fields. Soil chemical properties, soil microflora, and soil-inhabiting animals were investigated in paddy-converted and upland organic ginseng fields in Sangju city, Korea. There was few difference in the soil chemical properties, and the soil nutrient concentrations, such as nitrate-N, Av. $P_2O_5$ between the two field types, and exchangeable cations such as K and Ca were within the ranges which are recommended by the standard ginseng-farming manual. Changes in microflora were also assessed by analyzing phospholipid fatty acid composition. Overall, indicators of microbial groups were greater in the upland field than in the paddy-converted soil, but they were not significantly different. In addition, there was no significant change in the abundance of nematodes, collembolans, and mites between the two field types probably because of the high variation within the field types. In this study, it was suggested that soil chemical and biological properties for organic ginseng cultivation were greatly influenced by the variation of topography and soil management practices rather than field types. Further study may be needed to investigate the influence of these factors on soil chemical and biological properties in organic ginseng soils.