• 아시안잔디학회지
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• 제9권2호
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• pp.119-129
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• 1995

Decomposition rates of glucose, starch, spinach leaves and litters in forests are calculated by equation dC dt=-kC(Co-1nC), dC- dt=$-kC^2$, and Olson's negative exponential decay model.dC dt = - kC =-kC(Co - InC) showed a very close fit to decomposition of the organic matters in cultural media by purified microorganisms and dC dt=$-kC^2$ to decomposition of the litters in forests. Key words: Organic matters, Cultural media, Glucose, Starch, Leaves, Litters.

• 한국수산과학회지
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• 제24권5호
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• pp.356-361
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• 1991

This study was conducted to determine the decomposition rate constants of organic matter and to evaluate the process of regeneration of inorganic nutrients in coastal and open seawater. The mixture solution of glucose and glutamic acid, and night soil were used as the test organic matter. Oxygen uptake of test solution was observed every day for 5 days for evaluation of decomposition rate constants, and nutrient contents were analyzed every day for 40 days. The decomposition rate constants have been determined by Thomas slope method and compared with the values of each waters. The values of rate constants for open seawater and coastal water containing the mixture of glucose and glutamic acid were 0.23/day and 0.21/day, and those containing night soil 0.23/day and 0.20/day, respectively. The difference of decomposition rate constants between test materials was not found and the valus for each seawater was equal to each other. The nitrification process took place after 22 days for open seawater when night soil was added to the waters.

• 한국토양비료학회지
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• 제23권1호
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• pp.21-25
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• 1990

볏짚, 보리짚, 산야초(山野草) 그리고 활엽수(闊葉樹)와 침엽수(針葉樹)의 낙엽(落葉)을 채취(採取)하여 실험실(實驗室) 조건하(條件下)에서 90일간(日間) 부숙(腐熟)시키면서 경시적(經時的)으로 재료(材料)를 취(取)하여 산가수분해(酸加水分解)한 후(後) 단당류(單糖類)의 함량(含量)을 분석(分析)한 결과(結果)는 다음과 같다. 1. 부숙기간(腐熟其間)이 경과(經過)함에 따라 유기물중(有機物中) 단당류(單糖類)의 함량(含量)이 감소(減少)하였다. 중간단계(中間段階)(45일(日))에서는 일시적인 함량(含量)이 증가(增加)가 나타났다. 2. 보리짚이 볏짚보다 빠른 속도(速度) 부숙(腐熟)하였는데 활엽수낙엽(闊葉樹落葉)이 침엽수낙엽((針葉樹落葉)보다 빨리 부숙(腐熟)되었다. 3. 단당류(單糖類)의 함량(含量)은 산야초(山野草)나 산림낙엽(山林落葉)보다 볏짚 및 보리짚에 더 많았다. 4. 식물성(植物性) 단당류(單糖類)와 미생물성(微生物性) 단당류(單糖類)의 정량적(定量的) 구별(區別)은 불가능(不可能)하였다. 5. 단당류중(單糖類中) Glucose가 가장 많았으며 가장 적게 함유(含有)된 당(糖)은 Fucose이었다. Ribose는 검출되지 않았다. 6. 부숙기간(腐熟期間)이 경과(經過)함에 따라 Glactose의 상대적(相對的) 함량(含量)도 증가(增加)하였다. 7. 부숙기간(腐熟期間)이 증가(增加)함에 따라 Fucose의 상대적(相對的) 함량(含量)이 감소(減少)하였으며, Rhamnose도 이와같은 경향이었다. 다만, 볏짚의 경우 Rhamnose의 상대적(相對的) 함량(含量)은 오히려 증가(增加)하였다. 8. 부숙(腐熟) 90일경 각(各) 시료(試料)가 함유(含有)하고 있는 단당류(單糖類)의 양(量)은 다음과 같은 순서이었다. 볏짚 : Glucose > Xylose > Arabinose > Galactose > Rhamnose > Mannose > Fucose 보리짚 : Glucose > Xylose > Arabinose > Galactose> Mannose > Rhamnose > Fucose 산야초 : Glucose > Xylose > Galactose Arabinose > Rhamnose Mannose > Fucose 활엽수낙엽 : Glucose > Arabinose> Xylose Galactose > Mannose > Rhamnose = Fucose 침엽수낙엽 : Glucose > Xylose > Galactose > Arabinose Mannose > Rhamnose > Fucose.

• Journal of Microbiology and Biotechnology
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• 제34권9호
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• pp.1867-1875
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• 2024

Identification of the biochemical metabolic pathway for lignin decomposition and the responsible degradative enzymes is needed for the effective biotechnological valorization of lignin to renewable chemical products. In this study, we investigated the decomposition of kraft lignin by the soil bacterium Pseudomonas kribbensis CHA-19, a strain that can utilize kraft lignin and its main degradation metabolite, vanillic acid, as growth substrates. Gel permeation chromatography revealed that CHA-19 decomposed polymeric lignin and degraded dehydrodivanillin (a representative lignin model compound); however, the degradative enzyme(s) and mechanism were not identified. Quantitative polymerase chain reaction with mRNAs from CHA-19 cells induced in the presence of lignin showed that the putative genes coding for two laccase-like multicopper oxidases (LMCOs) and three dye-decolorizing peroxidases (DyPs) were upregulated by 2.0- to 7.9-fold compared with glucose-induced cells, which indicates possible cooperation with multiple enzymes for lignin decomposition. Computational homology analysis of the protein sequences of LMCOs and DyPs also predicted their roles in lignin decomposition. Based on the above data, CHA-19 appears to initiate oxidative lignin decomposition using multifunctional LMCOs and DyPs, producing smaller metabolites such as vanillic acid, which is further degraded via ortho- and meta-ring cleavage pathways. This study not only helps to better understand the role of bacteria in lignin decomposition and thus in terrestrial ecosystems, but also expands the biocatalytic toolbox with new bacterial cells and their degradative enzymes for lignin valorization.

• 한국미생물·생명공학회지
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• 제37권3호
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• pp.226-230
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• 2009

희석 황산용액을 사용해 볏짚을 전처리했는데 반응조건은 2개의 반응온도(140, $150^{\circ}C$)와 5개의 황산농도($1.0{\sim}3.0 %wt$)를 사용했다. 볏짚을 구성하는 주요성분인 glucose, xylose, galactose와 arabinose의 생성과 분해속도를 조사했는데 생성속도는 arabinose, 분해속도는 xylose가 가장 컸다. 헤미셀룰로오스당 (xylose+galactose+arabinose)의 최고수율은 약 80%이었는데 최고수율에 도달하는데 산 농도가 높은 것은 유리하지만 반응온도가 높은 것은 불리하게 나타났다. 최적조건은 $140^{\circ}C$, 2.5%와 20분이었다. 최고 glucose 수율은 반응조건에 관계없이 거의 같았는데 대략 $16{\sim}18%$ 범위였다.

• The Korean Journal of Ecology
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• 제9권4호
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• pp.231-241
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• 1986

The annual decomposition of cellulose and hemicellulose by microorganism and distribution of soil microbial flora were investigated in the humus horizon of a Pinus rigida stand in Mt. Kwanak. The cellulase activity was the lowest, 142$\mu$g glucose/g/hr from Dec. 1985 to Mar. 1986 and the highest, 760~1, 072$\mu$g glucose/g/hr in Jul. and Aug. 1985. The xylanase activity was 47% higher than the cellulase activity and was the lowest, 211~275$\mu$g xylose /g/hr from Feb. to Mar. 1986 and the highest as 799~1, 322$\mu$g xylose/g/hr from Jun. to Aug. 1986. The vertical distribution of the enzyme activity was decreased with the order of F, H, L, and A1 in both enzymes and the activities were exponentially decreased below L horizon, which suggests that most decomposition be done in F and H horizons with lots of organic matters. The SEM study slowed that the main decomposers of litters were fungi and initial attack into litters was also made by them. The enzyme activities of soil had strong correlations with the temperature and the precipitation. The correlation coefficients were 0.813 and 0.886 in the cellulase, and 0.673 and 0.626 in the xylanase for the temperature and the precipitation, respectively.

• Biomolecules & Therapeutics
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• 제12권1호
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• pp.25-33
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• 2004

In this study we investigated whether ATP loss was involved in the potentiated death of immunostimulated rat primary astrocytes in glucose-deprived condition. Rat primary astrocytes immunostimulated with LPS plus IFN-${\gamma}$ for 48 h underwent death upon glucose deprivation, which dependent on the production of peroxynitrite. Intracellular ATP level synergistically decreased by glucose deprivation in immunostimulated astrocytes but not in control cells, and the loss of ATP occurred well ahead of the LDH release. The synergistic cell death and ATP loss by immunostimulation and glucose deprivation were inhibited by iNOS inhibitor (L-NAME and L-NNA) or peroxynitrite decomposition catalyst (also a superoxide anion scavenger), Mn(III)tetrakis(N-methyl-4'-pyridyl)porphyrin (MnTMPyP). Exogenous addition of peroxynitrite generator, SIN-l timedependently induced ATP loss and cell death in the glucose-deprived astrocytes. Depletion of intracellular glutathione (GSH) and dis겨ption of mitochondrial transmembrane potential (MTP) were also observed under same conditions. Supply cellular ATP by the addition of exogenous adenosine or ATP during glucose deprivation inhibited ATP depletion, GSH depletion, MTP disruption and cell death in SIN-l treated or immunostimulated astrocytes. This study showed that perturbation in the regulation of intracellular ATP level in immunostimulated astrocytes might make them more vulnerable to energy challenging stimuli.

• Korean Chemical Engineering Research
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• 제60권2호
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• pp.193-201
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• 2022

바이오매스로부터 얻는 5-HMF(5-hydroxymethylfurfural)과 레불린산(LA; levulinic acid)는 그린 플랫폼 화학물질로, 폭넓은 응용분야를 가지며 바이오연료 및 바이오 화학물질로써 사용된다. 본 연구에서는, 글루코오스(D-glucose) 분해로부터 레불린산 형성의 kinetic를 다양한 온도 및 황산 농도를 통해 연구하였다. 실험은 황산 촉매(1-3 wt%)을 사용하였으며, 온도(140-200 ℃)는 넓은 범위에서 수행되었다. 글루코오스 용액은 10 ml 황산 용액에 글루코오스 1g을 용해시켜 만들었다. 반응 속도는 온도에 따라 증가하였고 활성화 에너지는 이전에 보고된 값과 유사한 경향을 보였다. 5-HMF의 최대 농도에 대한 반응 시간은 온도가 증가함에 따라 감소하였다. 또한, 산 농도가 증가함에 따라 5-HMF의 분해속도가 빨라졌다. 황산 촉매의 농도가 증가함에 따라 레불린산의 최대 농도에 도달하는 시간이 줄어들었다. 온도를 계속 높이는 것은 레불린산의 최대 농도를 감소시켰고 휴민의 양을 증가시켰다. 결과를 통해 얻은 kinetic parameters는 5-HMF과 레불린산의 mechanism를 이해하는데 도움을 준다. 또한, 이 연구의 결과는 바이오매스에서 고농도의 레불린산 및 5-HMF를 얻어내는데 유용한 정보를 제공한다.

• KSBB Journal
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• 제25권5호
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• pp.453-458
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• 2010

본 연구에서는 효소의 재활용성과 안정성을 확보하기 위해 자석으로 분리가 가능한 polyaniline nanofiber를 개발하였다. 개발된 고정화 효소는 상온에서 8일 동안 90% 이상의 활성도를 보유하였으며 온도가 높은 $55^{\circ}C$에서는 60% 이상의 활성도를 보유하여 안정성의 유지현상을 보였다. 개발된 고정화 효소는 자석으로 분리가 가능하였으며 이 효소를 이용하여 curdlan, agarose, cellulose, 및 미역을 분해한 결과 포도당을 생산하였으며 curdlan을 분해시킨 경우에는 분해 속도가 1.2 g/L/h로 나타나 다른 다당류에 비해 3-10배 이상 빠른 속도를 나타내었다. 고정화 효소를 반복하여 사용하는 경우 10번 반복 사용했을 때 75% 이상의 활성도를 유지하는 것으로 측정되었다. 젖은 미역 줄기를 10 g/L를 분해하기 위하여 5 mg의 고정화 효소를 사용한 결과 24시간 만에 1 g/L의 glucose를 생산하였다.

• 상하수도학회지
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• 제30권2호
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• pp.167-177
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• 2016

This work investigated the decomposition of aqueous anatoxin-a originated from cyanobacteria using an underwater dielectric barrier discharge plasma system based on a porous ceramic tube and an alternating current (AC) high voltage. Plasmatic gas generated inside the porous ceramic tube was uniformly dispersed in the form of numerous bubbles into the aqueous solution through the micro-pores of the ceramic tube, which allowed an effective contact between the plasmatic gas and the aqueous anatoxin-a solution. Effect of applied voltage, treatment time and the coexistence of nutrients such as $NO_3{^-}$, $H_2PO_4{^-}$ and glucose on the decomposition of anatoxin-a was examined. Chemical analyses of the plasma-treated anatoxin-a solution using liquid chromatography-mass spectrometry (LC-MS) and ion chromatography (IC) were performed to elucidate the mineralization mechanisms. Increasing the voltage improved the anatoxin-a decomposition efficiency due to the increased discharge power, but the energy required to remove a given amount of anatoxin-a was similar, regardless of the voltage. At an applied voltage of 17.2 kV (oxygen flow rate: $1.0L\;min^{-1}$), anatoxin-a at an initial concentration of $1mg\;L^{-1}$ (volume: 0.5 L) was successfully treated within 3 min. The chemical analyses using LC-MS and IC suggested that the intermediates with molecular weights of 123~161 produced by the attack of plasma-induced reactive species on anatoxin-a molecule were further oxidized to stable compounds such as acetic acid, formic acid and oxalic acid.