• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.301-307
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• 2011

Oil pollution was world-wide prevalent treat to the environment, and the physic-chemical remediation technology of the TPH (total petroleum hydrocarbon) contaminated soil had the weakness that its rate was very slow and not economical. Bioremediation of the contaminated soil is a useful method if the concentrations are moderate and non-biological techniques are not economical. The aim of this research is to investigate the influence of additives on TPH degradation in a diesel contaminated soil environment. Six experimental conditions were conduced; (i) diesel contaminated soil, (ii) diesel contaminated soil treated with microbial additives, (iii) diesel contaminated soil treated with microbial additives and the mixture was titrated to the end point of pH 7 with NaOH, (iv) diesel contaminated soil treated with microbial additives and accelerating agents and (v) diesel contaminated soil treated with microbial additives and accelerating agents, and the mixture was titrated to the end point of pH 7 with NaOH. After 10 days, significant TPH degradation (67%) was observed in the DSP-1 soil sample. The removal of TPH in the soil sample where microbial additives were supplemented was 38% higher than the control soil sample during the first ten days. The microbial additives were effective in both the initial removal rate and relative removal efficiency of TPH compared with the control group. However, various environmental factors, such as pH and temperature, also affected the activities of microbes lived in the additives, so the pH calibration of the oil-contaminated soil would help the initial reduction efficiency in the early periods.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.767-773
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• 2001

We investigated the impacts of the fairy-ring of Tricholoma matsutake on the dynamics of soil microflora and soil enzyme activities by grouping the soils around the fairy-ring of T. matsutake into four regions. The regions were grouped as 'zone of decayed mycorrhizae', 'zone of mycorrhizae for fruiting', 'zone of physiologically active mycorrhizae' and 'zone free from mycorrhizal infection'. Soil fungi and actinomycetes were quite little at the soils around the fairy-ring of T. matsutake compared to those of general forest soils, and there were significant differences among the four regions. The soils with the mycelial cluster of T. matsutake showed about one third of microbial population compared to those in the zone free from mycorrhizal infection, which indicated that T. matsutake took a dominant position within the fairy-ring of the fungus. We could manifest that T. matsutake showed a distinctive characteristics of mycorrhizal fungus since the activities of dehydrogenase were significantly different between the zone of physiologically active mycorrhizae and the zone free from mycorrhizal infection. The dehydrogenase activity was the highest at the early season of fruiting around the fairy-ring of T. matsutake, while the acid-phosphatase activity increased from March to June followed by a slight decrease on August and peaked on October. This phenomenon made us infer that the vitality of T. matsutake be sustained after fruiting.

• Korean Journal of Microbiology
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• v.51 no.2
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• pp.97-107
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• 2015

Wetlands constitute a transitional zone between terrestrial and aquatic ecosystems and have unique characteristics such as frequent inundation, inflow of nutrients from terrestrial ecosystems, presence of plants adapted to grow in water, and soil that is occasionally oxygen deficient due to saturation. These characteristics and the presence of vegetation determine physical and chemical properties that affect decomposition rates of organic matter (OM). Decomposition of OM is associated with activities of various extracellular enzymes (EE) produced by bacteria and fungi. Extracellular enzymes convert macromolecules to simple compounds such as labile organic carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) that can be easily taken up by microbes and plants. Therefore, the enzymatic approach is helpful to understand the decomposition rates of OM and nutrient cycling in wetland soils. This paper reviews the physical and biogeochemical factors that regulate extracellular enzyme activities (EEa) in wetland soils, including those of ${\beta}$-glucosidase, ${\beta}$-N-acetylglucosaminidase, phosphatase, arylsulfatase, and phenol oxidase that decompose organic matter and release C, N, P, and S nutrients for microbial and plant growths. Effects of pH, water table, and particle size of OM on EEa were not significantly different among sites, whereas the influence of temperature on EEa varied depending on microbial acclimation to extreme temperatures. Addition of C, N, or P affected EEa differently depending on the nutrient state, C:N ratio, limiting factors, and types of enzymes of wetland soils. Substrate quality influenced EEa more significantly than did other factors. Also, drainage of wetland and increased temperature due to global climate change can stimulate phenol oxidase activity, and anthropogenic N deposition can enhance the hydrolytic EEa; these effects increase OM decomposition rates and emissions of $CO_2$ and $CH_4$ from wetland systems. The researches on the relationship between microbial structures and EE functions, and environmental factors controlling EEa can be helpful to manipulate wetland ecosystems for treating pollutants and to monitor wetland ecosystem services.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.401-408
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• 1992

The extracellular cholesterol oxidase produced from a soil microorganism HSL613 was purified and partially characterized. Through a series of purification procedures including concentration with CH2 concentrator, DEAE-cellulose column chromatography and gel filtration on Superose12, the purified enzyme was shown to have a specific activity of 108 units/mg protein giving 30.8-fold purification and final yield of 66%. The molecular weight of the enzyme was estimated to be 59,500 daltons by SDS-PAGE. The optimum temperature and pH for this enzyme were $50^{\circ}C$ and 6.0, respectively. The activity of the purified cholesterol oxidase was inhibited by $Ag^{2+}$, $Hg^{2+}$ and SDS.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.1
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• pp.79-89
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• 2005

Forest soils were analyzed on their biological and physicochemical properties for the ecological restoration of burnt forest soil using organic wastes and proper microorganisms. Three kinds of soil samples were collected from undamaged soil(US), naturally restoring soil(NS) and artificially restoring soil(AS). All soil samples were sandy soil and acidic soil, ranged pH 5.34~5.78. Moisture content was higher in the soil of NS region. And the others were similar. Total organic matter and soluble sugar were higher at the surface, generally. Heterotrophic soil microbes were abundant at the surface soil of NS and subsoil of AS. Dehydrogenase, cellulase and phosphatase activities were higher at the NS soil. Especially, Dehydrogenase activity as primary index of soil microbial process showed high correlationship with moisture content(r=0.90, P < 0.05).

• Korean Journal of Microbiology
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• v.32 no.4
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• pp.291-296
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• 1994

A bacterial strain NO. AM-28, showing proteolytic activity against defatted soybean was isolated from domestic soil. The isolated strain was identified as Aeromonas hydrophila by both the biochemical tests using API kit and the analysis of cellular fatty acid profile with MIDI system. The protease production from A. hydrophila AM-28 was highly enhanced when it was cultivated in the medium containing glycerol as a carbon source, tryptone or $(NH_4)_2HPO_4$ as a nitrogen source, and $CaCl_2$ as a mineral source. The optimal pH and temperature for the enzyme was 8.0 and $65^{\circ}C$, respectively. The enzyme was stable up to $55^{\circ}C$ and at pH values ranging from 7.0 to 13.0. The enzyme activity was inhibited by phenylmethylsulfonyl fluoride and EDTA, indicating that serine residue and metal ions be involved in enzyme activity.

• KSBB Journal
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• v.24 no.6
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• pp.508-514
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• 2009

This study investigated the production of catalase from Bul-kyo soil bacteria through fermentation process. Isolation and selection of bacteria was performed through chemical and physiological analysis. Catalases were produced from bacteria which belong to 3 different species (Bacillaceae bacterium BKBChE-1, Bacillus sp. BKBChE-2, Bacillus flexus BKBChE-3) confirmed by using 16S rDNA sequence method. The catalases were found to be stable in the temperature range of $30^{\circ}C-60^{\circ}C$ for BKBChE-1, BKBChE-2 and BKBChE-3 and also in the pH range of 9.0-12.0 for BKBChE-1 and BKBChE-3. Long-term stability of the catalases was about 20 days at $4^{\circ}C$. However, BKBChE-2 has kept its activity over 30 days at $4^{\circ}C$.

• Journal of Urban Science
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• v.13 no.1
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• pp.1-8
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• 2024

정화곤란부지 내 중금속(Pb) 오염토양의 원위치 안정화를 위한 최적 안정화제 선정의 일환으로, 문헌조사를 통해 선정한 3종의 후보 안정화제(mono ammonium phosphate (MAP), iron(III) phosphate (IP) 및 gypsum)에 대해 납에 대한 등온흡착실험을 실시했다. Langmuir 등온흡착식을 적용하여 산출된 각 안정화제의 납 최대흡착량은 MAP, IP 및 gypsum에서 각각 391, 42.4 및 32.2 mg/g으로 나타났다. Freundlich 상수(K_F; 단위 = mg^(1-1/n)·L^1/n/g) 또한 MAP, IP 및 gypsum에서 각각 72.8, 24.5 및 14.3을 나타내, 최대흡착량 및 흡착 친화도 측면에서 MAP가 납의 안정화에 가장 적합함을 확인했다. 3종의 후보 안정화제가 적용된 납 오염토양에 대해 fluorescein diacetate (FDA) 가수분해효소 활성도 평가를 실시하여 안정화제의 적용이 토양의 생태학적 기능에 미치는 영향을 정량화했다. 안정화를 진행하지 않은 대조군 토양의 경우 FDA 가수분해효소의 활성을 지시하는 토양중 fluorescein의 농도가 0.239 mg/g·h을 나타냈으며, MAP, IP 및 gypsum으로 안정화된 토양에서는 각각 0.026, 0.135 및 0.073 mg/g·h를 나타냈다. 안정화제를 첨가한 모든 토양에서 대조군에 비해 FDA 가수분해효소의 활성이 감소했으며, 이는 안정화제 첨가로 인한 토양 염류농도의 증가에 따른 염 스트레스의 영향으로 추정된다. 정화곤란부지 위해도 저감조치로서의 안정화 공법 고려 시, 안정화 처리 이후 대상 중금속이 안정한 형태로 유지되어 낮은 화학적 추출능을 나타내는지 여부도 중요하지만, 잔류 중금속 또는 주입한 안정화제 함유물질 및 중화제 등이 야기할 수 있는 토양 생태계에의 부정적 영향 또한 반드시 고려해야 함을 확인했다.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.4
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• pp.375-385
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• 1987

This study was carried out to investigate the effects of pesticides on soil respiration, microflora and enzymes in loam soil, and on pathogenic microorganisms in continuous pepper cropping soil. The results are summarized as follows. No significant effect of pesticides on soil respiration was shown, with the exception of propoxur which slightly increased at $10{\mu}g\;g^{-1}$ treatment. When pesticides were treated, the amount of soil microorganisms generally decreased at the early stage of incubation and the number of microflora was much more decreased at 60-day incubation. When pesticides were treated, the amount of soil enzyme activity was inhibited at the early stage of incubation and gradually recovered at the last stage of incubation. The amount of polygalacturonase activity was increased at the 20-and 30-day incubation in propoxur treatment plot. The amount of ${\beta}$-glucosidase and dehydrogenase activity was increased at 20-and 60-day incubation in carbofuran and acephate treatment plot. The amount of phosphatase activity was increased at 60-day incubation in propoxur and isoprocarb treatment plot. The amount of Fusarium generally decreased in continuous pepper cropping soil, with the exception of isoprocarb and acephate treatment plot which significantly increased. The amount of Pythium increased at 60-day incubation with the exception of captan treatment plot which significantly decreased.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.696-701
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• 2011

This study was conducted to investigate impacts of soil properties on microbial distribution in Jeonbuk orchard fields. Soil samples were collected from 110 sites cultivated with different fruit plants. The population of aerobic bacteria and fungi and the content of soil microbial biomass carbon (C) were found to increase with increasing silt content in the soils. Different activity of dehydrogenase was not observed among the different textures of soil. Microbial distribution, amount of microbial biomass C, and dehydrogenase activity in the soils were not significantly different among the topographic sites. However, in pear and grape fruit plant fields, coliform group of bacteria was found in relatively higher population, $133.0{\times}10^3\;CFU\;g^{-1}$ and $107.4{\times}10^3\;CFU\;g^{-1}$, respectively. Microbial groups were simplified and their density was reduced with increasing the cultivation periods of fruit plants. The soil microbial distribution was proportionally correlated with some of soil properties such as soil pH, soil organic matter (SOM) content, and exchangeable Mg content; in particular, the population of Bacillus sp. was proportionally correlated with soil pH and exchangeable Mg content. The amounts of microbial biomass C and the dehydrogenase activity in the soils were significantly correlated with the contents of SOM and exchangeable Ca ion (p<0.01).