• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.3
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• pp.372-385
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• 2014

Lignin is an abundant natural polymer in the biosphere and second only to cellulose; however, it is under-utilized and considered a waste. In this study, lignin was fabricated into nanofibers via electrospinning. The critical parameters that affected the electrospinnability and morphology of the resulting fibers were examined with the aim to utilize lignin as a resource for a new textile material. Poly(vinyl alcohol) (PVA) was added as a carrier polymer to facilitate the fiber formation of lignin, and the electrospun fibers were deposited on polyester (PET) nonwoven substrate. Eleven lignin/PVA hybrid solutions with a different lignin to PVA mass ratio were prepared and then electrospun to find an optimum concentration. Lignin nano-fibers were electrospun under a variety of conditions such as various feed rates, needle gauges, electric voltage, and tip-to-collector distances in order to find an optimum spinning condition. We found that the optimum concentration for electrospinning was a 5wt% PVA precursor solution upon the addition of lignin with the mass ratio of PVA:lignin=1:5.6. The viscosity of the lignin/PVA hybrid solution was determined as an important parameter that affected the electrospinning process; in addition, the interrelation between the viscosity of hybrid solution and the electrospinnability was examined. The solution viscosity increased with lignin loading, but exhibited a shear thinning behavior beyond a certain concentration that resulted in needle clogging. A steep increase in viscosity was also noted when the electrospun system started to form fibers. Consequently, the viscosity range to produce bead-free lignin nanofibers was revealed. The energy dispersive X-ray analysis confirmed that lignin remained after being transformed into nanofibers. The results indicate the possibility of developing a new fiber material that utilizes biomass with resulting fibers that can be applied to various applications such as filtration to wound dressing.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.11
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• pp.1686-1694
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• 2019

Objective: Lignin plays a relevant role in the inhibition of cell wall (CW) structural carbohydrate degradation. Thus, obtaining accurate estimates of the lignin content in tropical plants is important in order to properly characterize the mechanism of lignin action on CW degradation. Comparing conflicting results between the different methods available for commercial use will bring insight on the subject. This way, providing data to better understand the relationship between lignin concentration and implications with tropical forage degradation. Methods: Five grass species, Brachiaria brizantha cv $Marand{\acute{u}}$, Brachiaria brizantha cv $Xara{\acute{e}}s$(MG-5), Panicum maximum cv Mombaça, Pennisetum purpureum cv Cameroon, and Pennisetum purpureum cv Napier, were harvested at five maturity stages. Acid detergent lignin (ADL), Klason lignin (KL), acetyl bromide lignin (ABL), and permanganate lignin (PerL) were measured on all species. Lignin concentration was correlated with in vitro degradability. Results: Highly significant effects for maturity, lignin method and their interaction on lignin content were observed. The ADL, KL and ABL methods had similar negative correlations with degradability. The PerL method failed to reliably estimate the degradability of tropical grasses, possibly due to interference of other substances potentially soluble in the $KMnO_4$ solution. Conclusion: ADL and KL methods use strong acid ($H_2SO_4$) and require determination of ash and N content in the lignin residues, therefore, increasing time and cost of analysis. The ABL method has no need for such corrections and is a fast and a convenient method for determination of total lignin content in plants, thus, it may be a good option for routine laboratory analysis.

• 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 Korea Foresty Energy
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• v.23 no.1
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• pp.45-68
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• 2004

The word of lignin is derived from the Latin word 'ligum' meaning wood. Lignin is complex polymer consisting of coniferyl alcohol, sinapyl alcohol and p-coumaryl alcohol unit and has an amorphous, three dimensional network structure which is hard to be hydrolyzed by acid. Lignin is found in the cell wall of plants lignified. The mode of polymerization of these alcohols in the cell wall lead to a heterogeneous branched and cross-linked polymer in which phenyl propane units are linked by carbon-carbon and carbon-oxygen bonds. This polymerization of precursors, p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol to lignin is formed by enzymic dehydrolyzation. The reaction is initiated by an electron transfer which results in the formation of resonance-stabilized phenoxy radical. The combination of these radicals produces a variety of dimers, trimers and oligomers and so on. Lignin research has been divided into basic and practical application field. The basic studies contains biosynthesis, chemical structure, distribution in the cell wall and reactivity by reductants, oxidants and organic solvents. The application research will be approached the reaction of lignin in various pulp making involving pulp bleaching and its effect on pulp qualities. Lignin also will be studied for the production of fine chemicals, polymer products and the conservation into an energy source like petroleum oil because the amount of lignin produced in pulp making process is more than 51,000,000 tons per year in the world. Both basic and application research must lay emphasis on the development for the utilization of lignin and the pulping process. But these researches can not be completed without understanding lignin structure containing functional groups. Therefore, this paper was focused on the review of lignin formulation which has been studied since 1948 in chronological order. This review was based on monomers, dimers, trimers and tetramers of phenyl propane unit structures which were isolated and identified by different methods from various wood.ious wood.

• Journal of the Korean Wood Science and Technology
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• v.12 no.3
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• pp.35-40
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• 1984

The ultraviolet absorption spectra of AcBr lignin (Acetyl Bromide lignin) from 10 species grown in Mt. Jiri were determined. There were 3 peak positions, at 249nm (max peak), at 267-268 nm (shallow min. peak) and at 280 nm (lower max. peak). The Bjorkman lignin and lignin sulfonic acid spectra had shoulders, but the AcBr lignin had not them. Average absorbances and absorptivities of the AcBr lignins at peak positions were $0.367{\pm}0.0015$, $24.56{\pm}0.0535$, at 249 nm, $0.278{\pm}0.0016$, $18.50{\pm}0.0569$, at 267-268 nm and $0.306{\pm}0.0016$, $20.42{\pm}0.0627$ at 280 nm, respectively.

• Journal of Life Science
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• v.12 no.4
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• pp.392-398
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• 2002

38 strains were isolated in order to utilize lignin degrading ability from soil and compost. A organism having high lignin degrading ability of the isolated strains determined morphologcal and biochemical characteristics. Enrichment technique yielded a lignin degrading bacterium characterized as Pseudomonas sp. LC-2. This strain was able to degrade lignin which are the true representatives of native lignin and transform lignin to a lot of aromatic compounds as HPLC analysis of culture. By polyacrylamide gel analysis, it was determined that peroxidase consisted of three enzymes, with only one, the lignin peroxidase having high activity.

• Journal of the Korean Wood Science and Technology
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• v.23 no.1
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• pp.13-20
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• 1995

This study was carried out to investigate the characterization of lignins from waste liquors in SP, KP, ASAM, and AS from Pinus densiflora, Quercus mongolica, and Betula ermanii. Spectroscopic study was applied to examine the lignins separated from different pulping process. Lignin contents in waste liqours increased in order of AS, ASAM, KP, and SP. UV spectra of three types of lignin except AS lignin showed similar pattern. IR spectra of AS lignin showed strong C=O absorptions in the range from 1730 to 1750$cm^{-1}$, where as those of KP, SP, and ASAM showed weak stretch in this region. NMR spectra of AS lignin showed strong characteristic chemical shifts of acetoxyl groups of acetylated aliphatic and aromatic hydroxyl groups at 2.0~2.5 ppm. Molecular weight of ASAM lignin from Pinus densiflora determined and found number average molecular weight 1,199, weight average molecular weight 5,458. z average molecular weight 17,242, and viscosity average molecular weight 5,457. It is considered from the results based on spectroscopic study of lignin that waste liquors (in SP, KP, ASAM and AS) from Pinus densiflora, Quercus mongolica, and Betula ermanii can be used for lignin utilization.

• Journal of the Korean Wood Science and Technology
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• v.47 no.4
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• pp.442-450
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• 2019

Despite its potential as a renewable source for fuels and chemicals, lignin valorization still faces technical challenges in many aspects. Overcoming such challenges associated with the chemical recalcitrance of lignin can provide many opportunities to innovate existing and emerging biorefineries. In this work, we leveraged a biomass genetic engineering technology to produce phenolic aldehyde-rich lignin structure via downregulation of cinnamyl alcohol dehydrogenase (CAD). The structurally altered lignin obtained from the Arabidopsis thaliana CAD mutant was pyrolyzed to understand the effect of structural alteration on thermal behavior of lignin. The pyrolysis was conducted at 400 and $500^{\circ}C$ using an analytical pyrolyzer connected with GC/MS and the products were systematically analyzed. The results indicate that aldehyde-rich lignin undergoes fragmentation reaction during pyrolysis forming a considerable amount of C6 units. Also, it was speculated that highly reactive phenolic aldehydes facilitate secondary repolymerization reaction as described by the lower yield of overall phenolic compounds compared to wild type (WT) lignin. Quantum mechanical calculation clearly shows the higher electrophilicity of transgenic lignin than that of WT, which could promote both fragmentation and recondensation reactions. This work provides mechanistic insights toward biomass genetic engineering and its application to the pyrolysis allowing to establish sustainable biorefinery in the future.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.343-349
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• 2001

This study characterizes the growth of white rot fungi Phanerochaete chrysosporium IFO 31249) and lignin peroxidase(LiP) activity in different submerged culture media. P. chrysosporium was grown in the form of pellet of various sizes from a spore inoculum under shaking liquid culture condition. While the growth of mycelia was higher under the nitrogen-sufficient culture than under the nitrogen-limited culture, ligninase activity was relatively lower. The lignin peroxidase appeared in nitrogen-limited culture and was suppressed by excess nitrogen. High level(40U/l) of lignin peroxidase activity was obtained in the growth medium containing 1.5mM veratryl alcohol, a secondary metabolite of P. chrysosporium. Lignin peroxidase production was not observed under conditions of nitrogen sufficiency or in balanced media, suggesting that control parameters could increase the activity by manipulating the secondary metabolism.