• Journal of Plant Biotechnology
• /
• 제42권2호
• /
• pp.93-103
• /
• 2015

The isolation, cloning, and characterization of an R2R3-MYB transcription factor gene (MtMYB70) from the model legume Medicago truncatula is reported. MtMYB70 consists of a 768-bp coding sequence corresponding to 255 amino acids. Sequence alignment revealed that MtMYB70 cDNA contains conserved R2R3-type MYB domains with highly divergent C terminal regions. MtMYB70 was found to have relatively low sequence homology with known R2R3-MYB genes. Phylogenetic analysis placed the R2R3-MYB domain of MtMYB70 closest to PtMYB1, a known activator of lignin biosynthesis. Overexpression of MtMYB70 under the control of the 35S promoter in transgenic poplar did not cause a significant difference in total lignin content relative to the control, but glucan content was significantly increased in transgenic poplar. Therefore, MtMYB70 might have regulatory role in the biosynthesis of cell wall structural carbohydrates.

• 펄프종이기술
• /
• 제48권1호
• /
• pp.53-60
• /
• 2016

Abiotic-stressed tobacco stems as a non-wooden biomass were analyzed for their chemical characteristics. Light-stressed tobacco stems (LST) have a relatively high nitrogen concentration, much more extractive content, and a similar amount of lignin and higher contents of acid sugars than those of Non stressed tobacco (NST). It also has low cellulose crystallinity and a high degree of condensation. Guaiacyl units having a lower molecular weight distribution consist of rich lignin. Tension stressed tobacco (TST) growth differentiation under tensile stress was significantly different between normal tissue and cell walls, with the exception of the slightly higher cellulose crystallinity observed for.

• Carbon letters
• /
• 제25권
• /
• pp.103-112
• /
• 2018

Hierarchically porous, chemically activated carbon materials are readily derived from biomass using hydrothermal carbonization (HTC) and chemical activation processes. In this study, empty fruit bunches (EFB) were chosen as the carbon source due to their sustainability, high lignin-content, abundance, and low cost. The lignin content in the EFB was condensed and carbonized into a bulk non-porous solid via the HTC process, and then transformed into a hierarchical porous structure consisting of macro- and micropores by chemical activation. As confirmed by various characterization results, the optimum activation temperature for supercapacitor applications was determined to be $700^{\circ}C$. The enhanced capacitive performance is attributed to the textural property of the extremely high specific surface area of $2861.4m^2\;g^{-1}$. The prepared material exhibited hierarchical porosity and surface features with oxygen functionalities, such as carboxyl and hydroxyl groups, suitable for pseudocapacitance. Finally, the as-optimized nanoporous carbons exhibited remarkable capacitive performance, with a specific capacitance of $402.3F\;g^{-1}$ at $0.5A\;g^{-1}$, a good rate capability of 79.8% at current densities from $0.5A\;g^{-1}$ to $10A\;g^{-1}$, and excellent life cycle behavior of 10,000 cycles with 96.5% capacitance retention at $20A\;g^{-1}$.

• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
• /
• pp.173-176
• /
• 2006

Pyrolysis-gas chromatography (Py-GC) in the presence of organic alkali of tetrabutylammonium hydroxide (TBAH) was applied to characterize the polyphenol fragments with a carbonyl group causing different magnitude of photo-yellowing in chemithermomechanical pulp (CTMP) papers. Two different origin of CTMP papers prepared from different individuals of Eucalyptus globulus trees showing high and low yellowing after photo-irradiation was compared before photo-irradiation. As a result, 7 peaks assigned to a series of phenol compounds with a carbonyl group, derived mainly from lignin, gave significant amount of phenol compounds with a carbonyl group for the paper sample of latent high yellowing, i.e., butoxy-and syringaldehyde, butoxy-and syringylacetone, butoxy-acetoguaiacone, butoxy-acetosyringone, butoxy-acetoethylsyringone, 3-methoxy-4-butoxy butyl ester, and 3,5-dimethoxy-4-butoxy butyl ester, using Py-GC/mass spectrometry (MS). The Py-GC method combined with TBAH successfully characterized polyphenol fragments with a carbonyl group causing differ high photo-yellowing in CTMP papers using a microgram order of samples.

• 한국의류학회지
• /
• 제28권7호
• /
• pp.873-881
• /
• 2004

This research was aimed to investigate the effect of enzyme and the addition of chelators on rotting of the Kenaf bast. Enzyme rotting was effective only when the chelators were added with the enzyme. EDTA was a more effective chelator than oxalic acid under 1% concentration. There was no difference in the rotting effect under different enzyme concentration levels, and under different treatment time and temperature. Therefore, it was found that enzyme rotting can be carried out with low enzyme concentration(0.125%) at room temperature. Retting time can be shortened when higher enzyme concentration and higher temperature are applied. Cellulose I structure of kenaf fiber did not change after enzyme rotting, and different enzyme concentration did not affect the crytallinity structure. Non-cellulosic matters such as hemicellulose, lignin, and pectin were present in the descending order in the enzyme rotted kenaf fiber, and there were no differences in their amounts due to enzyme concentration levels. There was no difference in the dyeabilities of kenaf fiber rotted with different enzyme concentration levels. Enzyme rotted kenaf fiber showed better cyeability when pectin, lignin, and hemicellulose were removed.

• 한국축산식품학회지
• /
• 제18권1호
• /
• pp.42-49
• /
• 1998

The contents of holocellulose, one of the main components of the wood, were 83.9% in oak wood and 76.9% in apple wood, respectively. Those of hemicellulose were 16.41 and 20.33%, and in lignin 23.0 and 19.7%, respectively. Six species of domestic oak wood and apple wood were considered to be suitable for smoking materials due to the low content of lignin. Benzo(a)pyrene contents in smoke flavoring prepared with oak wood at 150, 400 and 500$^{\circ}C$ were 0. 4, 3. 7 and 5.6$\mu\textrm{g}$,/kg, respectively. The amounts of phenanthrene were 112.7, 131.4 and 255.9$\mu\textrm{g}$/kg, respectively, in each temperature. The amounts of polycyclic aromatic hydrocarbons(PAH) in smoke flavory were in the order of phenanthrene＞anthracene＞pyrene＞benzo(a)anthracene＞chrysene＞benzo(b)fluoranthens＞benzo(a)pyrene Benzo(a)pyrene contents in smoking extracts prepared with apple wood at 150, 400 and 500$^{\circ}C$ were 0.4, 3.3 and 5.5$\mu\textrm{g}$/kg, respectively. Phenanthrene contents in those samples were 72.7, 100.2 and 220.5$\mu\textrm{g}$/kg, respectively. Contents of each PAH showed the same order as in oak wood.

• 한국작물학회지
• /
• 제48권5호
• /
• pp.372-375
• /
• 2003

In order to examine the possibility that oil seed rape could be used as a forage fodder crop and to select the most suitable variety of forage rape at the southern area of Korea, two varieties of oil seed rape currently grown for oil production and six introduced varieties of forage rape with relatively high yield and high nutritional value were grown at the same condition and their nutritional value were observed. Generally, rape was considered as a useful forage fodder crop with high content of crude protein and low contents of NDF, ADF, hemicellulose, cellulose and lignin. Differences in mean values of the above characters between two groups of rape were not statistically significant. Velox showed significantly higher content of crude protein and significantly lower contents of NDF, ADF, hemicellulose, cellulose and lignin compared with other varieties of forage rape. Rape was relatively high in IVDMD compared with other forage fodder crops, and forage rape was more or less higher in IVDMD and DDMM than oil seed rape. Velox was the highest in IVDMD and DDMM among the varieties of forage rape in this experiment.

• Journal of the Korean Wood Science and Technology
• /
• 제22권2호
• /
• pp.54-60
• /
• 1994

The pine bark from mechanical pulp industry was cooked with bisulfite liquor, and the chemical and physical properties of the spent liquor after cooking for 90 minutes, which allowed partial defibration were determined. Lignosulfonate or lignin-related materials in the spent liquor have a molecular weight of approximately 3,000, which is lower than that of commercial lignosulfonate (C-LS) prepared from wood. The sulfonic equivalent weight calculated by colloid titration was 307 for C-LS, 238~239 for spent liquor. The contents of lignosulfonic acid and phenolic hydroxyl groups on $C_9$ unit of lignin in the spent liquor were 0.98~0.99, and 1.51~1.66, respectively. These values were remarkably higher than those of C-LS. Especially the content of phenolic hydroxyl group was almost twice that of C-LS. The viscosity of spent liquor after freeze drying was very low compared to C-LS. The dispersing ability of spent liquor was almost equivalent to or more than that of C-LS.

• 한국의류학회지
• /
• 제30권7호
• /
• pp.1025-1033
• /
• 2006

Kenaf bast can be obtained by decortication of Kenaf stem. Kenaf fibers are much more rough than cotton fiber because they include impurities as pectin, lignin and hemicellulose besides cellulose. The purpose of this research is to investigate the distribution of kenaf fiber length and diameter during the processes of removing impurities. To remove pectin, kenaf bast was retted chemically. A half of the retted kenaf fiber bundle were scoured and bleached. The other half one were treated with $NaClO_2$ solution to remove lignin, and were treated with sodium hydroxide solution to remove hemicellulose. Four kinds of specimens that were obtained for investigating physical characteristics. Length and diameter of 100 fibers on each specimen was measured. The tensile strength of 100 fiber bundles were measured. And also the color values of them were measured with spectrocolorimeter. The length of retted kenaf fiber was 16.97cm. Then it decreased to 11.43cm after bleaching. Kenaf fiber bundles could be finer by chemical processes that remove non-cellulosic materials. The thickness of retted fiber was $132{\mu}m$. And after undergoing the chemical processes to remove non-cellulosic materials, the thickness of kenaf fiber became finer as $73{\mu}m$. Tensile strength of the retted kenaf fiber bundles was 11.37Mpa. The retted kenaf fiber lost their strength as 22.6% by bleaching and as 18.3% by treatment for removing lignin. The retted kenaf fiber showed low whiteness as 56.48 of L*value. After bleaching, the kenaf fibers have creamy white color and their whiteness got 90.02 of L*value. After the treatment for removing hemicellulose, the kenaf fibers also have creamy white color and their whiteness got L* value of 79.02.

• Journal of the Korean Wood Science and Technology
• /
• 제33권6호통권134호
• /
• pp.79-86
• /
• 2005

아스펜 목재(Populus tremuloides, L.)를 Ceriporiopsis subvermispora로 1, 2, 4, 6주 동안 부후 처리한 후, 목재의 화학적 성상변화를 관찰하였으며, 부후목재로부터 리그닌(MWL)을 단리하여 Gel permeation chromatography (GPC) 분석과 nitrobenzene oxidation (NBO)을 실시하였다. 부후가 진행되면서 목재내 리그닌의 함량은 계속 감소하여 6주 후에는 미처리재와 비교하여 20%까지 감소하였다. 리그닌은 균주처리에 의하여 저분자화되어 알칼리에 쉽게 용출되는 것으로 예측된다. 부후목재의 전섬유소(Holocellulose) 함량은 미처리재와 비교하여 5~6% 정도 감소하였다. 부후 과정 동안 $\alpha$-셀룰로스의 함량은 커다란 변화가 관찰되지 않았으나, xylose의 함량은 대조구의 23.4%에서 6주후에는 18%까지 감소하였다. 아스펜 목재의 리그닌 분자량은 균주처리에 의해서 점차 감소되었다가 부후 6주 이후에는 안정화 단계에 접어드는 경향을 보였다. 단리한 리그닌의 NBO 분석 결과, NBO 분해산물의 수율은 대조구와 비교하여 6주처리 후에는 20% 가량 감소되었다. 특히, 부후 목재 리그닌에서 S-타입 유도체(syringaldehyde+syringic aicd)의 감소량이 두드러졌다. G-타입 유도체(vanillin+vanillic acid)의 수율은 부후가 진행되면서 약 20% 가량 증가되었는데, 이는 부후과정에서 리그닌 분해 효소에 의한 S-리그닌의 탈메톡실화 반응이 진행되었음을 암시한다. 결론적으로, C. subvermispora는 부후 과정동안 G-리그닌보다 S-리그닌을 더욱 선택적으로 분해하는 경향을 나타내었다.