• KSBB Journal
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• v.9 no.2
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• pp.133-139
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• 1994

Oligosaccharide formation and the production of transfructosylase and transglucosylase by Aureobasidium pullulans were studied in sucrose or maltose media, respectively. The initial uptake rates of substrate in sucrose-rich media were faster than that in maltose-rich media, also most parts of oligosaccharides formed and other monosaccharides released were utilized progressively as substrate during the cultivation periods. However, when the initial amount of sucrose was raised to $100g/\ell$, high concentration of monosaccharides were liberated, consequently high-level fructose was accumulated unused during fermentation. The biggest molecule of oligosaccharide synthesized was hexasaccharide in all cultivation media examined, of which the organism could not utilize isomalto-oligosaccharide of DP6 synthesized in a maltose-rich medium. The maximum amount of oligosaccharides produced was $58g/\ell$ when $100g/\ell$ of sucrose and $5g/\ell$ of maltose were used as initial substrate. From the early stage of growth both fructooligosaccharides and isomalto-oligosaccharides were synthesized and progressively utilized as substrates during the fermentation. Based on the experimental results, it was suggested that maltose could induce both transfructosylase and transg1ucosylase, whereas sucrose was unable to slimulate transglucosylase formation.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.352-357
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• 1998

Biodegradation of benzoate and m-toluate was investigated using a Pseudomonas sp. isolated in a continuous culture for 45 days with a step-wise increase of the subsrates. The optimum mixture ratio of benzoate and m-toluate was 75% and 25%, respectively. During 45-day culture, removal of benzoate and m-toluate, which was replaced 2,000 ppm on the 30th day were 94% and 79%, respectively, when COD removal rate was 80%. The enzymatic activity of catechol 1,2-dioxygenase increased and that of catechol 2,3-dioxygenase decreased as the concentration of m-toluate was increased. These results suggested that m-toluate induced enzyme activity for degradation of benzoate. The shape of isolated strain in the continuous culture was investigated with SEM and the results showed that the cell shape was more damage according to the higher concentration of aromatic hydrocarbons. Therefore, we suggested that the tolerance against aromatic hydrocarbons was related to not only enzymatic activity but also characteristic of cell membrane or cell wall.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.97-108
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• 2000

A Gram-type negative bacteria that can utilize crude oil as the sole source of carbon and energy was isolated from an activated sludge of a local sewage treatment plant and identified tentatively as belonging to the genus Acinetobacter. The isolate could degrade n-alkanes and unidentified hydrocarbons in crude oil and utilize n-alkanes, hydrophobic substrates, as sole carbon and energy sources. n-Alkanes from tridecane (Cl3) to triacontane (C30) in crude oil were degraded simultaneously with no difference in degradation characteristics between the two close odd and even numbered alkanes in carbon numbers. The linear growth of the isolate and the degradation characteristics of Pr-alkanes suggested that the transport of substrates from the oil phase to the site where the substrates undergo the initial oxidation in microorganism might be the rate limiting in the biodegradation process of crude oil constituents. The remainder fraction of substrates after cultivation was considered to reflect the hydrocarbon inclusions in the cell mass, characteristics in Acinetobacter species, and to control the transport of substrates from crude oil phase. On the basis of the results, the isolate was considered to play an important role in the degradation study of hydrophobic environmental pollutants.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.602-607
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• 1993

These studies were conducted to investigates the changes in physicochemical characteristics of Charbori (waxy-barley) and Olbori (normal) during kernel maturation. 1000-kernel weight increased as the barley matured and as the original moisture decreased. The amount of total nitrogen per endosperm was similar in both cultivars. 1000-kernal weight had a correlation coefficient of $r=-0.871^{**}$ with water soluble nitrogen and of $r=-0.894^{**}$ with nitrogen solubility index. At maturity, the starch content of Olbori was 26% higher than Chalbori. Amylose content ranged from 20.4 to 24.7% in Olbori and from 9.9 to 12.9% in Chalbori as the kernel matured. ${\beta}-glucan$ viscosity was no differences at the early stages of development, but at 40 days after heading, was greatly differences between Chalbore and Olbori, 7.9 kand 5.8 cST, respectively. Gelatinization characteristics and other properties of the starch by Amylograph were compared with those of Olbori and Chalbori. The Chalbori starch usually had a lower initial temperature and setback.

• Journal of Soil and Groundwater Environment
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• v.14 no.6
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• pp.45-52
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• 2009

Naphthalene-degrading bacteria Pseudomonas aeruginosa CZ6 isolated from contaminated soil can adhere to crystal naphthalene and produce extracellular polymeric substance. LB, YM and MSM medium were used as culture mediums to investigate the formation of biofilm. Biofilm was developed the most in LB medium by Pseudomonas aeruginosa CZ6. In the culture, strain CZ6 growth was rarely affected by naphthalene concentration. Optimal culture condition was $30^{\circ}C$ and pH 7 at 0.10% substrate and 150 rpm shaking. The effect of culture medium on naphthalene degradation in the two soil slurry system was evaluated. The initial degradation rate of naphthalene was highest in the MSM medium of soil slurry. However, the sorbed naphthalene was rapidly degraded at the LB medium when naphthalene availability in liquid was limited. The results of this study suggest that biofilm formation and extracellular polymeric substance production increased bioavailability of soil sorbed naphthalene.

• Journal of the Korean GEO-environmental Society
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• v.15 no.5
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• pp.39-46
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• 2014

The objectives of this study were to determine biodegradation and characteristics of BTEX and MTBE under aerovic-anaerobic conditions and evaluate the potential of natural attenuation method in denitrifying condition.. In the single-substrate experiments, all of the BTEX compounds were degraded under all the conditions. but, lower degradation of benzene and p-xylene were observed under aerobic condition due to the lack of oxygen initially supplied. In the mixed-substrate experiments, BTEX degradation was delayed compared to that in the single-substrate experiments due to a competition of the substrates. Biodegradation of MTBE was observed only under denitrifying conditions and we expected that MTBE mineralized to $CO_2$ without the accumulation of TBA. We also conducted to determine the effect of initial nitrate concentration on BTEX and MTBE degradation. At low nitrate concentration (<50 mg/L), BTEX degradations were limited by the lack of electron acceptor and BTEX degradation was inhibited at high nitrate concentration (>200 mg/L). The results in this study indicated that biotransformation could be applied to the gasoline-contaminated region under aerovic-anaerobic.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.374-377
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• 2003

The purpose of this study was to investigate the characteristics of anaerobic methane fermentation using several organic wastes. The substrates used in this study were food wastes, vegetable wastes, and cow manure. The substrates were mixed with inocula (mixed methanogenic fluid) at a ratio of 1:1, and several parameters such as TS, VS, sCOD, and biogas production have been monitored. Anaerobic degradation of food wastes were occurred in the intial stage of cultivation, whereas that of vegetable wastes were occurred in the late stage. However, in case of cow manure, the degradation was occurred two times both in the intial and the late stage of reaction.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1093-1097
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• 2006

하천수계는 여러 인자들의 상호작용을 통하여 변화하게 되며, 하천 자정능력에 관한 연구는 이를 중심으로 진행되어 왔다. 여러 환경 요인 중 하상재료는 하천의 조도와 수생태계의 특성을 변화시키게 되며, 유입수의 성상에 따라 수저퇴적물이 쌓이거나, 생물막이 형성되는 매개체 역할을 하게 된다. 특히, 하천의 폭이 좁고 수심이 얕은 개울에서는 하상 퇴적물이 수질에 기여하는 영향이 큰 것으로 알려져 있다. 국내하천의 경우 하상재료가 주로 모래와 자갈이 주를 이루고 있으며, 수심이 낮아 빛의 투과성이 양호하여 부착조류의 증식 및 하상재료(모래 및 자갈 등)를 기질로 한 생물막 형성 등 하상재료는 하천환경의 변화 및 수질변화가 일어나는데 상당한 기여를 하는 것으로 보고되고 있다. 본 연구에서는 하천의 하상재료가 설치된 수로를 이용하여 이화학적요소를 조사, 분석함으로써 하상재료를 통한 수질변화 특성을 비교.검토 하였다. 그 결과 하상재료의 입경이 클수록 DO 변화가 더 큰 폭으로 증가 하였으며, 수위와 유속의 경우 수위가 낮으면서 유속이 적정수준일 경우 DO 증가가 나타나는 것으로 관측되었다. 하천수가 수로에 의해 순환되면서 유기물 저감속도의 측정결과 초기 흡착, 침전 등의 물리적 작용이 부착조류 증식 등의 생물학적 작용보다 우선되면서 입자성 유기탄소(POC)의 제거속도가 용존성 유기탄소(DOC) 의 경우보다 더 빠르고 우선되는 것으로 조사되었다. 영양염류의 경우 부착성조류에 의한 질소 제거능은 실제 질산화작용은 활발히 이루어졌으나 탈질작용에 의한 총질소의 제거는 미비한 것으로 나타났으며, 총인은 입자성유기탄소가 제거되는 것과 유사한 경향을 나타내 제거 기작이 대부분 흡착, 침전에 의한 물리적 자정 작용에 기인한 것으로 조사되었다. 또한 하상재료 입경 변화에 따른 수질변화 특성은 기질(하상재료)의 입경이 작을수록 오염물질의 분해능이 큰 것으로 나타났다. 이와 같이 여러 하천환경 요인 중 하상재료에 의한 하천환경의 다양한 변화는 수질변화 및 자정능력에 큰 영향을 미치게 된다.

• KSBB Journal
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• v.4 no.2
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• pp.191-196
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• 1989

Functional relationship between the Fermentation characteristics of Functional relationship between the Fermentation characteristics of S. cerevisiae SIV-89 and the fermentation time was investigated. According to the increase in the initial sugar cone. from 50g/L to 80 g/L, maximum specific growth rate and maximum specific alcohol production rate were increased until 0.35 and 1.98. But the two values were decreased with increase of initial sugar cone. in the region of more that 80 g/L. Maximum alcohol yield and biomass yield were 0.45 and 0.15 respectively. However those vlaue were found to be reduced with the argument of initial sugar concentration. Sugar conversion was decreased with sugar concentration. When the sugar concentration was more than 190 g/L, the conversion was dropped below 70%. The increase of alcohol concentration in the fermentation broth induced the phenomenon of decline of metabolism. In case of more than 80 g/L of alcohol conc., biomass growth and alcohol production were completely stopped regardless of remaining sugar concentration.

• Journal of Soil and Groundwater Environment
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• v.8 no.4
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• pp.45-52
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• 2003

A gas-substrate degrading bacterium, Nocardia SW3, was isolated from the gasoline contaminated aquifer using propane and butane as carbon and energy sources. We have examined the effects of substrate concentration, temperature and pH on the gas substrate degradation as well as MTBE cometabolic degradation. The result for the effect of substrate concentration showed that the maximum degradation rates of propane and butane were 30.6 and 25.4 (n㏖/min/mg protein) at 70 $\mu$㏖, respectively. The optimum temperature and pH for the degradation of gas substrate were $30^{\circ}C$ and 7, respectively. Substrate degradation activity, however, was still active in broad range of pH from 5 to 8 and temperature between $15^{\circ}C$and$35^{\circ}C$. The degradation activity of Nocardia SW3 for the MTBE was similar to the both substrates. The observed maximal transformation yields ($T_y$) were 46.7 and 35.0 (n㏖ MTBE degraded $\mu$㏖ substrate utilized), and the maximal transformation capacities ($T_c$) were 320 and 280 (n㏖MTBE degraded/mg biomass used) for propane and butane oxidizing activity on MTBE, respectively. And also, TBA was detected as by-product of MTBE and it was continuously degraded further.