• Journal of the Korean Wood Science and Technology
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• v.32 no.3
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• pp.15-24
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• 2004

The present work was undertaken to investigate the anatomical and chemical characteristics of transgenic poplar down-regulated with antisense OMT gene. Also the distribution of lignin in transgenic poplar trees was investigated at cellular level. No visible abnormal phenotype was observed in the fibers and vessel elements of transgenic poplar. Any marked differences in the staining intensities of Wiesner and Mäule color reaction were not identified in the transgenic poplar. TEM micrographs did not show any staining intensities in the cell walls stained with KMnO₄. Interestingly, the UV spectroscopy of semi-thin sections exhibited a distinct decrease of lignin absorption at 280 nm in the vessel walls, indicating transgenic poplar wood with lower amount of guaiacyl lignin in vessel elements. Chemical composition of antisense OMT poplar was almost identical to that of wild-type poplar. Klason lignin content of transgenic poplar did not show any significant difference from that of the controls. The solid state NMR spectra revealed the transgenic poplar with only slightly more syringyl lignin than the control. The present work showed that antisense OMT gene constructed in the poplar was not enough to reduce the overall content of Klason lignin, and suggested that the expression of transformation was confined to vessel walls.

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.323-328
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• 1986

To clarify the effects of several carbohydrates on the biodegradation of lignin by Pleurotus ostreatus. The strain was cultured on the media formulated with lignin and carbohydrates such as cellulose, xylan, collobiose, glucose and xylose, which was added individually. The culture mixtures grown 36 days were filtered and then estimated the degree of lignin biodegradation. It was found that the growth of P. ostreatus was stimulated and the depoly-merization was also increased by the addition of carbohydrates. When the carbohydrates were not added, polymerization was apparent in stead of depolymerization. In the case of glucose as an added carbohydrate, the content of lignin by the nitrosolignin method was greatly (about 7.4 times) decreased than control which contains lignin as a carbon source. The peak of lignin at 280nm in UV spectra was decreased about 27% after 27 days of culture. As results, it was assumed that lignin biodegradation was correlated to the carbohydrates and especially glucose was very significant role in lignin degradation.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.103-108
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• 1991

The chemical characteristics of lignin in the differentiating xylem were investigated and compared with those of mature-wood. The compound middle lamella lignin deposited in the early stage of lignification of cell walls in the softwood(Larch) as well as the hardwood(Birch) was confirmed to be the so-called guaiacyl-type lignin and was found to have a relatively larger content of phenoxy hydroxyl group as terminal units and to be more abundant in condensed-type structures like as phenylcoumaran structures compared with mature-wood lingin.

• Journal of the Korean Wood Science and Technology
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• v.12 no.4
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• pp.19-30
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• 1984

This experiment was carried out to investigate the effects of autohydrolysis and extraction conditions on the separation of the chemical substances, the extractability of lignin by dioxane, and the yield of reducing sugars from cellulosic substrates by using a commercial cellulase derived from Trichoderma viride. Air-dried wood meals through 0.42mm (40 mesh) screen and retained on 0.25 mm (60 mesh) of Populus alba-glandulosa and Pinus koraiensis were autohydrolyzed with water at $180^{\circ}C$ for 30 and/or 60 minutes in a 6 liter stainless-steel digester with or without 2% 2-naphthol. The hydrothermally-treated wood meals were extracted the lignin with 100%, 90%, 75% and 50% dioxane solutions at $70^{\circ}C$ for 4 hours, respectively. The results obtained were as follows; 1) After autohydrolysis of Populus alba-glandulosa, the yield of wood meals decreased with lengthening the auto hydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. In case of Pinus koraiensis, the yield was not affected by 2%, 2-naphthol addition at the autohydrolysis in the digester. 2) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the yield of wood meals decreased with lengthening the autohydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. Extraction of 50% dioxane solution was the best solvent for the yield among the solutions of 100%, 90%. 75% and 50% dioxane. In case of Pinus koraiensis, the yield was not affected by 2% 2-naphthol addition and the solution of 90% dioxane was the poorest solvent for the yield. 3) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the Klason lignin content in cellulosic substrates for enzymatic hydrolysis decreased with lengthening the autohydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. Klason lignin content was the lowest after extraction by 90% or 75% dioxane solution. The content was also affected by interaction of the three factors-autohydrolysis time, 2% 2-naphthol addition and concentration of dioxane. In case of Pinus koraiensis, the Klason lignin content increased with 2% 2-naphthol addition but was not affected by the concentration of dioxane solution. 4) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the extractable Klason lignin content by extraction increased with lengthening the auto hydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. The extractable lignin content was the highest after extraction by 90% or 75% dioxane solution. In case of Pinus koraiensis, the extractable lignin content increased with 2% 2-naphthol addition. Extractions by 100%, 90% and 50% dioxane solutions were more effective for the extraction of Klason lignin than by 75% dioxane solution. 5) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the yield of reducing sugars increased with lengthening the autohydrolysis time from 30 minutes to 60 minutes but was not affected by 2% 2-naphthol addition and the concentration of dioxane. The yield of reducing sugars after enzymatic hydrolysis was slightly higher by extractions with 90%, 75% and 50% dioxane solutions than with 100% dioxane. In case of Pinus koraiensis, the yield of reducing sugars was not affected by 2% 2-naphthol addition but affected by the concentration of dioxane. The yield of reducing sugars was the highest in cellulosic substrates extracted by 100% dioxane solution.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.257-263
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• 2006

This paper examines the physico-chemical properties and structural features of thio lignin and alcohol lignin preparations extracted from fast-growing poplar wood. The lignin preparations were characterized using UV, IR and alkaline nitrobenzene oxidation methods. The yield was higher in thiolignin due to its preparation from wood under drastic alkaline conditions and almost the total amount of alkaline degraded lignin was precipitated except acid soluble lignin. In case of ethanol lignin, structural modifications were comparatively less and form a cream colored lignin more or less similar to its original natural color. The methoxyl values were higher due to syringyl unit present in hard wood lignin in addition to guaicyl unit present in soft wood. The higher values of methoxyl content of isolated lignin revealed that it was built up of high syringyl units. The elementary analysis, methoxyl group and hydroxyl groups were presented by $C_{9}$ formula indicated that it was made up of phenyl propane monomers. Nitrobenzene oxidation of thio lignin and ethanol lignin yield more or less the chromatograms of similar pattern, except difference in relative percentage. The ultra violet spectra of lignins were quite similar, irrespective of the source and method of isolation. Infrared spectroscopy studies of poplar deltoides, thio and ethanol lignin shown different absorption bands which have been utilized for structural investigations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.303-311
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• 1986

This work was designed as basic studies on the development of diet for the treatment of obesity. The effect of alginic acid which is the major component of brown algae was investigated by comparing with agar, cellulose, carboxymethylcellulose (CMC), chitin, and lignin as dietary fibers. These dietary fibers ($10\%$) supplemented to basic diet were fed ad libitum to Sprague Dawley rat for 4 weeks, and the inhibitory effects on obesity were evaluated by measuring body weight gain and feed efficiency, the content of glucose and cholesterol in serum, lipase activity in serum, lipid content in liver, adipose tissue around epididymis and ovarium, and Lee index etc. Among the inhibitory effect of these dietary fibers on obesity, lignin was the most effective (p<0.001), followed by Na-alginate (p<0.01) for body weight gain, but lignin was the most effective, followed by CMC, and followed by Na-alginate for feed efficiency (p<0.001). In the inhibitory effects on lipid accumulation in liver and adipose tissue around epididymis and ovarium, lignin and Na-alginate group among these dietary fibers were more effective than others, but there was no significant difference between male and female. The inhibitory effect on obesity evaluated by Lee index was effective in the order of Na-alginate>lignin>CMC>chitin>cellulose (p<0.001). The decreasing effects of lipid content in liver by dietary fibers were found in the order of agar>CMC>cellulose>Na-alginate>chitin>lignin (p<0.001). Glucose content in serum was significantly decreased in cases of CMC, lignin and Na-alginate, whereas a slight difference was found in chitin, but cholesterol content in serum was decreased for all dietary fibers examined except cellulose group. The increasing effect of lipase activity in plasma was found in cases of Na-alginate and chitin, while cellulose, CMC and lignin groups were decreased.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.5 s.108
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• pp.62-68
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• 2004

The amount of non-lignin components in unbleached and oxygen-delignified kraft pulps and their impact on lignin determinations was investigated. The lignin analyses investigated were kappa number and Klason lignin in conjunction with acid-soluble lignin. The species investigated were loblolly pine, and aspen. The non-lignin components that impacted on lignin determination were residual extractives and hexenuronic acid in unbleached and oxygen-delignified kraft pulps. In the hardwoods, significant amounts of extractives remained after kraft pulping and oxygen delignification. These residual extractives in the hardwood pulps had an impact on the lignin determination, more so on the acid lignin method than kappa number. Hexenuronic acid only impacts on kappa number determination both softwood and hardwood pulps, not on acid lignin. Hexeneuronic acid contributed as lignin content more in aspen than pine pulps, and more in oxygen-delignified than unbleached kraft pulps. Impact of hexenuronic acid on should be corrected both softwood and hardwood pulps for accurate kappa number.

• Journal of the Korean Wood Science and Technology
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• v.44 no.1
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• pp.124-134
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• 2016

The main goal of this study was to investigate biomodification mechanism of lignin by white rot fungus, Abortiporus biennis, and to depolymerize ethanol organosolv lignin for industrial application. In nitrogen-limited culture, A. biennis polymerized mainly lignin showing a rapid increase of molecular weight and structural changes depending on incubation days. At the initial incubation days, cleavage of ether bonds increased phenolic OH content, while the results were contrary in of the later part of the culture. Based on these results, ascorbic acid as a reducing agent was used to induce depolymerization of lignin during cultivation with white rot fungus. As a result, the degree of increase of average molecular weight of lignin was significantly declined when compared with those of the ascorbic acid free-experiment, although the molecular weight of fungus treated sample slightly increased than that of control. Furthermore, lignin derived oligomers in culture medium were depolymerized with the addition of ascorbic acid, showing that the average molecular weight was 381 Da, and phenolic OH content was 38.63%. These depolymerized lignin oligomers were considered to be applicable for industrial utilization of lignin. In conclusion, A. biennis led to the polymerization of lignin during biomodification period. The addition of ascorbic acid had a positive effect on the depolymerization and increase of phenolic OH content of lignin oligomers in medium.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.1
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• pp.23-28
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• 2011

The pine wood meal was ozonated in acidic water. A 91.3% of lignin and 13% of polysaccharides in pine wood meal were degraded with 180 min ozonation. The phenolic hydroxyl groups of lignin in ozonated wood meals were increased with ozonation time. The vanillin content in nitrobenzene oxidation products of lignin is decreased with 10 min. ozonation and it was slightly increased with ozonation time. The sugar composition of ozonated wood meals showed that the hemicellulose was more susceptible to ozonation than cellulose. The crystallinity of ozonated wood meal was increased.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.277-277
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• 2022

Lignin modification has been a breeding target for the improvements of forage digestibility and fermentation in whole crop silage(WCS) rice. In rice, gold hull and internode 2 (gh2) was identified as a lignin-deficient mutant. gh2 exhibits a reddish-brown pigmentation in the hull and the internode is located on the short arm of chromosome 2 and codes for cinnamyl-alcohol dehydrogenase (CAD). To develop WCS rice variety improved digestibility and fermentation, we measured acid detergent fiber (ADF), lignin and total digestible nutrient (TDN) calculated from ADF (TDN=88.9-(0.79% × ADF) and performed marker-assisted selection using CAD(Os2g0187800) gene first intron region specific marker with 55 Jungmo1038/J.collection lines. Those lines had lignin content range from 0.82 to 6.61%, ADF from 15.8 to 45.8%, TDN from 52.7 to 78.8 compared to 'Jungmo1038'(1.53,20.7,72.6), 'J.collection'(0.98,12.8,78.8%) and gh2 were introgressed into 44 lines. Considering on these genotype and low-lignin phenotype, we finally selected 2 elite lines(Suweon668, Suweon669). Suweon668 and Suweon669 line are high biomass-low lignin lines that the ADF content is relatively low, even though the dry matter weight is high. Also they have lodging and shattering resistance and glabrous leaf and hull important to improve cattle palatability. Our results will provide that rice can be improved for forage digestibility and fermentation with low lignin concentration.