• Journal of Soil and Groundwater Environment
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• v.12 no.2
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• pp.20-26
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• 2007

The microbial community properties of groundwater samples contaminated with landfill leachates were examined using Ecoplate including 31 sole carbon sources. The samples were KSG1-12 (leachate), KSG1-16 (treated leachate), KSG1-07 (contaminated groundwater), KSG1-08 (contaminated groundwater), and KSG1-13 (uncontaminated groundwater). Among the carbon sources used as substrates, 2-hydroxy benzoic acid, D,L-$\alpha$-glycerol phosphate, and D-malic acid were not utilized in any sample, while D-xylose, D-galacturonic acid, L-aspargine, tween 80, and L-serine were utilized in all 5 samples. The rest of substrates showed very different patterns among the samples. Average well color development (AWCD) analysis demonstrated that the potential activity on 31 substrates was in the order of KSG1-16 > KSG1-12 > KSG1-07 > KSG-08 > KSG1-13, which generally agrees with the degree of pollution, except KSG1-16. Principal component analysis (PCA) on similarity between samples showed two groups (KSG1-12, -07 and -08 vs KSG1-16 and -13), coinciding with contaminated and uncontaminated groups. Shannon index showed that the microbial diversities were similar among the samples.

• Korean Journal of Food Science and Technology
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• v.47 no.6
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• pp.687-697
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• 2015

With the shortage of edible fats and oils and depletion of fossil fuels in many countries, microbial lipids is emerging as one of the most promising sources of fats and oils in the global market. Oleaginous microorganisms, also called single cell oils (SCOs), can accumulate lipids more than 25% in the cell volume. Triacylglycerols are the major storage lipids. SCOs offer several advantages for lipid production as follows: SCOs have short life span which would shorten production time, cultivation conditions are not affected by climate and place; the production process is easy to control. There are a number of oleaginous yeasts, molds, and microalgae. Furthermore, the lipid productivity of SCOs can be enhanced through strain improvement and the optimization of cultivation conditions. The new strains developed using recent advanced biotechnical methods showed greatly improved oleaginicity. Further, hydrolysates of lignocellulosic materials can be used as carbon sources for economic production of SCO.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.57-62
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• 2003

A bacteria strain producing extracellular $\beta$-mannanase was isolated from soil and was identified as Bacillus subtilis by 16S rRNA sequence comparison and biochemical determinations. The optimum pH and temperature for the $\beta$-mannanase activity were 5.0 and 5.5$^{\circ}C$, respectively. The zymogram technique revealed a single protein band exhibiting $\beta$-mannanase activity from the culture supernatant. The molecular mass of the enzyme was estimated at approximately 130 kDa. The addition of 0.5% lactose or 0.5% locust bean gum to the LB medium caused to Increase significantly the $\beta$-mannanase productivity from Bacillus subtilis JS-1. The cells grown on LB medium supplemented with lactose produced maximal enzyme activity at the stationary phase. In contrast to this, the $\beta$-mannanase was induced at the logarithmic phase from the cells grown on LB medium supplemented with locust bean gum. The discrepancy in induction times suggests that $\beta$-mannanase was induced by different induction mechanisms depending on the carbon sources in Bacillus subtilis JS-1 .

• Journal of Life Science
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• v.32 no.7
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• pp.510-522
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• 2022

In this study, to biosynthesize PHA with properties more similar to polypropylene, a Bacillus sp. EMK-5020 strain that biosynthesized poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was isolated from soil. Bacillus sp. EMK-5020 strain biosynthesized PHBV containing 1.3% 3-hydroxyvalerate (3HV) using reducing sugar contained in Makgeolli lees enzymatic hydrolysate (MLEH) as a single carbon source. As the amount of propionic acid, which was added as a second carbon source, increased, the content of 3HV also increased. PHBV containing up to 48.6% of 3HV was synthesized when 1.0 g/l of propionic acid was added. Based on these results, the strain was cultured for 72 hr in a 3 l fermenter using reducing sugar in MLEH (20 g/l) and propionic acid (1 g/l) as the main and secondary carbon sources, respectively. As a result, 6.4 g/l DCW and 50 wt% of PHBV (MLEH-PHBV) containing 8.9% 3HV were biosynthesized. Through gel permeation chromatography and thermogravimetric analysis, it was confirmed that the average molecular weight and the decomposition temperature of MLEH-PHBV were 152 kDa and 273℃, respectively. In conclusion, the Bacillus sp. EMK-5020 strain could biosynthesize PHBV containing various 3HV fractions when MLEH and propionic acid were used as carbon sources, and PHBV-MLEH containing 8.9% 3HV was confirmed to have higher thermal stability than standard PHBV (8% 3HV).

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.390-392
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• 2003

Organic solvent tolerant bacterium, Pseudomonas savastanoi BCNU 106 could utilize trichloroacetic acid, monochloroacetic acid, trichloroethylene, p-dichlorobenzene as a sole carbon source. But Pseudomonas savastanoi BCNU 106 didn't have tolerance about trichloroacetic acid, monochloroacetic acid, trichloroethylene, p-dichlorobenzene. Strain BCNU 106 could utilize to the extend of 30 mM trichloroacetic acid as a sole carbon source on mineral salt medium.

• Korean Journal of Microbiology
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• v.23 no.3
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• pp.230-234
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• 1985

A bacterium which can utilize malonate as a sole carbon source was isolated from soil. This strain was identified to be Acinetobacter calcoaceticus by morphological, cultural, phtsiological and biochemical examination. When this microorganism was grown on malonate as a aole carbon source, the enzymes, such as malonyl-CoA synthetase, isocitrate lyase and malate synthase were induced. These results suggest that in this microorganism, malonate is also assimilated through the proposed pathway in Pseudomonas fluorescens: $malonate{\rightarrow}malonyl-CoA{\rightarrow}acetyl-CoA{\rightarrow}glyoxylate\;cycle$.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.77-83
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• 2005

기후변화협약에 의해 탄소세가 부과될 경우 한국의 에너지 집약 산업에 어떠한 영향을 미치며 그에 대한 대응방안이 어떻게 마련되어야 하는지에 대한 관심이 증대되고 있다. 이에 본 연구에서는 탄소세가 부과됨으로 인하여 에너지 다소비 업종인 시멘트산업의 각 에너지원별 사용량에 미치는 파급효과를 시스템 다이내믹스 방법론에 의한 시뮬레이션 모델을 이용하여 분석하였다. 시뮬레이션 모델은 환경모듈, 경제모듈, 에너지모듈로 구성하였고 모델의 예측력 검증을 위해 의태분석을 수행하였다. BAU 시나리오와 탄소세 부과 시나리오를 설정하여 각 시나리오의 총수요의 예측치, 이산화탄소 배출량의 추이, 에너지원의 사용변화를 분석하였다. 본 연구는 향후 기후변화협약의 부담이 큰 에너지 집약산업에 있어서 에너지원의 사용 및 수요를 예측하고 이를 평가하기 위한 지침을 제시할 수 있을 것으로 기대된다.

• Clean Technology
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• v.17 no.2
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• pp.134-141
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• 2011

The effects of the compounds and concentrations of nitrogenous electron acceptor, the ratio of electron donor/electron acceptor (C/N), and the complexity of electron donor on the emission of $N_2O$ during wastewater denitrification were quantitatively investigated in this study. The higher ${NO_3}^-$ and ${NO_2}^-$ concentrations, the more $N_2O$ emission was observed. ${NO_2}^-$ has strong effect on $N_2O$ emission as it emitted morc $N_2O$ than ${NO_3}^-$, 50 mg/L of ${NO_2}^-$-N gave the highest conversion (9.3%) and yield (9.8%) of $N_2O$ while ${NO_3}^-$-N (50 mg/L) gave 5.6% conversion and 11.0% yield. Lower C/N ratio decreases nitrogen removal efficiency, but it increases the conversion of $N_2O$ because of the incomplete denitrification by the limited organic carbon. When real domestic wastewater is used as the electron donor of the denitrification, $N_2O$ emission is reduced to 1/10 of the emission when single carbon (acetate) is used. It is thought that multiple carbon source utilizes many denitrification pathways and it seems to be helpful for the reduction of $N_2O$ emission.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.460-465
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• 2007

In this study, the removal characteristic of ammonia nitrogen and behavior of nitrogen was investigated using Leclercia adecarboxylata, which was derived from the culture contaminated by ammonia nitrogen of high concentration. The method of ammonia nitrogen removal was not biological nitrification and denitrification but elimination of nutrient salt with internal synthesis of microorganisms which use ammonia nitrogen as substrate. L. adecarboxylata(one of ammonia synthesis microorganisms) was highly activated and showed the most high removal efficiency in free salt condition but the removal efficiency decreased badly in salt concentration of more than 4%. About 80 mg/L of $NH_3-N$ was mostly removed within 20 hours and 500 mg/L of $NH_3-N$ showed less then removal efficiency of 50% because carbon source was not enough. However, ammonium nitrogen concentration was decreased again when the carbon source was inserted additionally thus, ammonium nitrogen removal efficiency by L. adecarboxylata, was related to amount of carbon source. pH decreased from 8.0 to 6.36 according to growth of L. adecarboxylata. Concentration of nitrite nitrogen and nitrate nitrogen did not increase and TKN concentration showed no variation while ammonia nitrogen was removed by L. adecarboxylata. In addition to, when content of protein in organic nitrogen was measured, protein was not detected at the beginning of microorganism synthesis but protein of 193.1 mg/L was detected after 48 hours. Hence, ammonium nitrogen was not decomposed as nitrate nitrogen and nitrite nitrogen but synthesized by L. adecarboxylata, which has excellent ability of nitrogen synthesis and can threat ammonia nitrogen of high concentration in wastewater.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.71-74
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• 2002

다고리방향족 탄화수소를 페놀에 적응된 미생물을 이용하여 분해하고자 하였다. 분리된 Stenotrophomons maltophilia는 나프탈렌과 페난스렌을 탄소원 및 에너지원으로 이용하였으며 10mg/$\ell$의 나프탈렌과 0.9mg/$\ell$의 페난스렌이 완전히 분해되는데 지체기후 약 2일과 3일이 소요되었다. 나프탈렌, 페난스렌의 분해시 중간생성물로 chromatography 상에 새로운 피크들이 생성되었으며, 이러한 중간생성물을 파악하여 다고리 방향족 탄화수소의 분해경로를 모색하고자 하였다.