• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.5
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• pp.291-293
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• 2003

Batch reactors were employed to investigate the kinetics of cellulose hydrolysis under extremely low acid (ELA) and high temperature condition. The sawdust was pretreated by Auto-hydrolysis prior to the batch reaction. The maximum yield of glucose obtained from the batch reactor experiment was about 70% for the pretreated sawdust, this occurred at 210 and 22$0^{\circ}C$. The maximum glucose yield from the untreated sawdust was much lower at these temperatures, about 55%. The maximum yields of glucose from the lignocellulosics were obtained between 15th and 20th minutes after which gradual decrease was observed.

• Journal of the Korean Wood Science and Technology
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• v.12 no.4
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• pp.36-46
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• 1984

In order to investigate the inhibitory index (I) and the effects of hot water extraction treatments and addition of accelerators on the index in hardening of Korean lignocellulosics, portland cement (Type I) and water system, hydration tests were carried out on 8 Korean lignocellulosics, namely, Pinus densiflora, Pinus rigida, Pinus koraiensis, Abies holophylla, Larix leptoiepis, Populus alba-glandulosa, rice husk and rice stalk with or without hot water extraction or chemical additives. The inhibitory index of Pinus densiflora and Pinus rigida found to be suitable under limited conditions for composite without any treatment. With hot water treatment rice husk, Pinus koraiensis, Larix leptolepis, and A hies holophylla were reclassified from not suitable to suitable under limited conditions. Combining hot water extraction with chemical addition of accelerator, calcium chloride of magnesium chloride, Populus alba-glandulosa, Larix leptolepis, and Pinus rigida became highly suitable.

• Polymer Science and Technology
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• v.8 no.5
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• pp.596-607
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• 1997

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.525-528
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• 2006

아임계 및 초임계수에 의한 목질바이오매스의 당화특성을 분석하기 위하여 분해공정 동안 압력을 23MPa(물의 임계압력)로 고정하고 물의 아임계 온도$(325^{\circ}C,\;350^{\circ}C)$와 초임계 온도$(380^{\circ}C,\;400^{\circ}C,\;425^{\circ}C)$에서 현사시나무 목분을 각각 60초 동안 처리하였다. 생성된 현사시나무의 분해산물에는 액상과 고형분의 분해산물이 섞여 있었다. 각 처리조건에 따른 목질바이오매스의 분해율은 온도가 상승함에 따라 증가하였으며 초임계 온도인 $425^{\circ}C$에서 최고 83.1%의 분해율을 나타냈다. 아임계 및 초임계수에 의해서 생성된 단당류는 고성능 음이온 교환 크로바토그래프(HPAEC)를 이용하여 분석하였다. 목질바이오매스의 초임계수 분해과정에서 처리 온도가 높아지면서 단당류 수율은 증가하는 경향을 보였으며, $425^{\circ}C$에서 가장 높은 7.3%의 단당류 수율을 나타내었다. 아임계 온도 범위에서는 현사시나무의 섬유소 성분 중에서 자일란이 우선적으로 분해되어 자일로스의 생성비율이 비교적 높았으며, 처리온도가 높아지면서 셀롤로오스의 분해에 의한 글루코오스 생성율이 급격히 상승하였다. 이렇게 생성된 단당류 성분들은 고온의 반응조건하에서 열분해 반응에 의해서 더욱 분해되어 퓨란계 화합물로 변형되었다.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.522-528
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• 2016

In this study, we investigated the possibility of using hydrolysates of lignocellulosics (rapeseed straw, barley straw, rice straw) and marine macro-algae (Undaria pinnatifida, Laminaria japonica, Enteromorpha intestinalis, and Gracilaria verrucosa) to cultivate Chlorella saccharophila. The growth of C. saccharophila was inhibited by 7 hydrolysates without active carbon treatment. In contrast, hydrolysates treated with active carbon increased the cell growth and product (oil and chlorophyll) formation by C. saccharophila. The oil contents of C. saccharophila treated with each hydrolysate were $41.26{\pm}0.69%$ (glucose), $22.06{\pm}1.21%$ (rapeseed straw), $28.65{\pm}1.08%$ (barley straw), $31.15{\pm}0.76%$ (rice straw), $31.50{\pm}2.12%$ (U. pinnatifida), $31.49{\pm}4.53%$ (L. japonica), $29.63{\pm}3.93%$ (E. intestinalis), and $26.15{\pm}1.99%$ (G. verrucosa), respectively. Lignocellulosics and marine macro-algae may be useful resources for improving the mass cultivation of C. saccharophila.

• New & Renewable Energy
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• v.3 no.1 s.9
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• pp.38-45
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• 2007

To characterize thermo-chemical feature of sugar conversion of woody biomass, poplar wood ($Populus\;alba{\times}glandulosa$) powder was treated with supercritical water system. Supercritical water treatment (SCWT) was performed for 60 seconds at different temperatures (subcritical zone 350; supercritical zone $300,\;400,\;425^{\circ}C$) under two pressures $230{\pm}10atm$ as well as $330{\pm}10atm$, respectively, using flow type system. After separation of solid residues from SCWT products, the monomeric sugars in aqueous part converted from poplar wood powder were quantitatively determined by high performance anionic exchange chromatography [HPAEC] equipped with PAD detector and Carbo Pac PA10 column. As the temperature treated increased, the degradation of poplar wood powder was enhanced and ca 83% of woody biomass was dissolved into the water at $425^{\circ}C$. However, the pressure didn't help the degradation of biomass components. At subcritical temperature range, xylose was first formed by degradation of xylan, which is main hemicellulose component in hardwood species, while cellulose degradation started at the transition zone between sub and supercritical conditions and was remarkably accelerated at the supercritical temperature. In the supercritical water system the maximum yield of monomeric sugars amounts to ca. 7.3% based on oven dried wood weight at $425^{\circ}C$.

• Biomolecules & Therapeutics
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• v.12 no.3
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• pp.189-193
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• 2004

Over the past several years, research efforts have been directed both at economically producing valuable substances from the wood biomass and at producing lignolytic enzymes at a lower cost. In the present study, we found that Phellinus igniarius, the basidiomycetes, secreted lignin peroxidase as a main lignolytic enzyme, which was detected maximum activity at 16th day of culture and showed 37 kDa of molecular mass in identification by activity assay and purification by anion-exchange chromatography. The Phellinus igniarius-derived lignin peroxidase hydrolyzed steam-exploded wood (Quercus mongolica) powder into small molecules showing cytotoxicity against cancer cel1s (HepG2 hepatoma, SK-N-SH neuroblastoma, B16 melanoma, MBT-2 bladder cancer). In addition, the enzyme hydrlysates of lignins (ELg) that were extracted from the steam-exploded oak showed more potent cytotoxic effects on the cancer cells than the enzyme hydrolysates of wood biomass (EWp), indicating that the cytotoxic effect of EWp may be due to the enzyme-degraded products of lignin among the lignocellulosics. Furthermore, the cytotoxic effect of ELg on Chang, normal liver cells, was much less potent than that of ELg on HepG2 and B16 cancer cells, indicating that the cytotoxic effect of ELg may be specific for cancer cells. The present results suggest that Phellinus igniarius may be a useful resource for the large-scale production of lignin peroxidase and that the lignin peroxidase may be applied for the generation of valuable biodegradation products from wood lignocellulosics for medical use.

• Journal of the Korean Wood Science and Technology
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• v.18 no.4
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• pp.79-85
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• 1990

Many kinds of acetosolv lignin including ricestraw and spruce lignin were pyrolyzed. and liquefied in the autoclave reactor using 50% tetralin and m-cresol solution respectively as soluble solvent and Co-Mo as catalyst. In order to promote deoxyhydrogenolysis reaction $H_2$ gas was supplied into the reactor. The ratio between lignin and the soluble solvent are lg and 10cc. The reaction conditions are $200^{\circ}-700^{\circ}C$ of reaction temperature, 10-50 atms of reaction pressure and 100-500rpm of the reactor stirrer. By the deoxyhydrogenolysis liquefaction reaction, the main chemical structures of lignin which are aryl-alkyl-${\beta}$-0-4 ether, phenylcoumaran and biphenyl etc. are easily destroyed into liqufied aromatic compounds and aliphatic compunds linked with aromatic compounds. The percent yield of monomeric phenols on the weight bvase of lignin reacted reached to 12-14% by the chemical analytic GC-MS etc.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.206-209
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• 2008

The modified supercritical water treatment method is adopted for hydrolysis of wood powder, Populus alba$\times$glandulosa. This modified method is containing 0.05% HCl or $HNO_3$ as acid catalyst. The supercritical water treatment(SCW) was performed for 1 min. with $350^{\circ}C$, $380^{\circ}C$, $400^{\circ}C$ and $425^{\circ}C$, respectively, under 230 $\pm$ 10 atm using continuous flow system. When acid was added to powder prepared for SCW treatment, the yields of monomeric sugars were significantly increased. The lignin remained after supercritical treatment was applied to gel permeation chromatography(GPC) for molecular weight distribution analysis. Compared to the lignin produced from SCW treatment without acid catalyst, the average molecular weight of lignin compounds treated with acid was clearly decreased. Particularly, Mn/Mw ratio is decreased. This result shows supercritical water treatment of wood powder can change the molecular weight of lignin to small size. However, it is necessary to be further studied for exactly characterizing the lignin produced from supercritical water treatment.

• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.172-182
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• 2014

Extraction is a necessary element in the bioconversion of lignocellulosics to fuels and chemicals. Although various forms of chemical pretreatment of cellulosic materials have been proposed, their effectiveness varies depending on the treatment conditions and substrate. In this study, mixed hardwood (MH) and loblolly pine (LP) were pretreated with dilute acid in a 100 mL accelerated solvent extraction (ASE) at the predetermined optimal conditions: temperature: $170^{\circ}C$, acid concentration: 0.5% (w/v), and reaction time: 2~64 min. This method was highly effective for extracting the hemicellulose fraction. Total xmg (defined as the sum of xylose, mannose, and galactose) can be extracted from milled MH and LP through pressurized dilute acid treatment in maximum yields of 12.6 g/L and 15.3 g/L, respectively, representing 60.5% and 70.4% of the maximum possible yields, respectively. The crystallinity index increased upon pretreatment, reflecting the removal of the amorphous portion of biomass. The crystalline structure of the cellulose in the biomass, however, was not changed by the ASE extraction process.