Comparative Studies on Cellulolytic Enzyme Lignin and Milled Wood Lignin of Sweetgum and Spruce

Abstract

Keywords Milled wood lignin Cellulolytic enzyme lignin Enzyme lignin Liquidambar styraciflua Picea abies Sweetgum Spruce Schlüsselwörter (Sachgebiete) B j örkman-Lignin Cellulolytisch.es Enzym-Lignin Enzym-Lignin Liquidambar styraciflua Picea abies Amberbaum Fichte Comparative Studies on Cellulolytic Enzyme Lignin and Milled Wood Lignin of Sweetgum and Spruce SummaryMilled wood lignin (MWL) and Cellulolytic enzyme lignin (CEL) were isolated from the same batch of ball milled sapwood of sweetgum and Norway spruce. Ball milling decreased the molecular weight and increased the -carbonyl and the phenolic-hydroxyl content of lignin. Thus, the content of these functional groups in the original lignin in wood is less than that of isolated MWL and CEL. Compared to MWL, CEL of each species was very similar in elemental composition and both UV and IR spectra. A slightly greater extent of condensation and, in the case of sweetgum, a slightly smaller ratio of syringyl-to guaiacyl-propane units were found in MWL than in CEL. This indicates probable structural differences in lignin in various regions of wood cell walls. Despite these small differences, however, we conclude that MWL is adequately representative of the total lignin in wood but CEL is preferable for future studies of lignin structure because it is more representative of the total lignin in wood and can be obtained in good yield with less degradation due to ball milling. Vergleichende Untersuchungen an Cellulase-Enzym-Lignin und Björkman-Lignin von Sweetgum und Fichtenholz ZusammenfassungSplintholz von Sweetgum (Liquidambar styraciflua L.) und Fichte (Picea abies L.) wurde in einer Kugelschwingmühle gemahlen. Aus jeweils denselben Ansätzen wurde Björkman-Lignin ("Milled Wood Lignin", MWL) und durch Ein Wirkung von Cellulase freigelegtes Lignin (Cellulolytisches Enzym-Lignin, CEL) isoliert. Der Mahlvorgang führte zur Verminderung des Molekulargewichts und zur Erhöhung des Gehaltes an a-Carbonylgruppen und phenolischem Hydroxyl der untersuchten Lignine. Der Vergleich von MWL mit CEL beider Arten zeigte die große Ähnlichkeit dieser Ligninpräparate in bezug auf Elementarzusammensetzung und spektrale Eigenschaften (IR, UV). Die MWL zeigten einen etwas höheren Kondensationsgrad und das MWL von Sweetgum ein etwas niedrigeres Verhältnis von Syringylpropan-zu Guajacylpropaneinheiten als die CEL. Dies dürfte auf die unterschiedliche Zusammensetzung der Lignine in verschiedenen Teilen der Zellwand zurückzuführen sein. Trotz dieser geringen Unterschiede ergibt sich, daß MWL zureichend repräsentativ für das gesamte Lignin des Holzes ist. Trotzdem ist CEL dem MWL vorzuziehen, da es in noch höherem Grade dem Lignin in situ entspricht und außerdem in guten Ausbeuten auch bei geringerer Mahldauer auf schonende Weise erhalten werden kann.

Naturally p-Hydroxybenzoylated Lignins in Palms

“…The dried materials were ball-milled using a stainless steel vibratory ball mill for 1.5 h (with 0.5 h on, 0.5 h off, to minimize heating). The ballmilled materials (50 g) were submitted to enzymatic digestion with crude cellulases (Cellulysin, Calbiochem) for polysaccharide degradation [25,54,55]. As with aspen and poplar, the enzymatic treatment was particularly efficient at removing polysaccharides, leaving just 22.2 and 20.9 % of the cell wall from the EFB and frond samples, respectively.…”

HSQC-NMR analysis of lignin in woody (Eucalyptus globulus and Picea abies) and non-woody (Agave sisalana) ball-milled plant materials at the gel state 10th EWLP, Stockholm, Sweden, August 25–28, 2008

“…Other approaches are: 1) subjecting the milled wood to enzymatic treatment with cellulolytic enzymes to remove most of the carbohydrate components (Chang et al 1975;Wu and Argyropoulos 2003;Holtman et al 2004;Hu et al 2006); 2) completely dissolving ball-milled wood in a solvent system (dimethylsulfoxide, DMSO, and N-methylimidazol, NMI) followed by precipitation in dioxane/water in the course of which lignin and carbohydrate fractions are separated (Fasching et al 2008); or 3) isolating most of the lignin as lignin-carbohydrate complexes after endoglucanase treatment (Henriksson et al 2007). However, it is well recognized that these lignin preparations, in particular the MWL due to its low yield, represent only a part of the native lignin in the wood cell wall and may not be representative of the whole lignin present.…”

Characterization of Lignin Isolated from Wheat Leaf Based on LiCl/DMSO Dissolution and Regeneration

“…Currently, the most widely used lignin preparations for structure studies are milled-wood lignin (MWL) (Björkman 1954) and cellulolytic enzyme lignin (CEL), with the CEL being structurally similar to the MWL (Chang et al 1975). Fasching et al (2008) developed a novel method for lignin isolation based on a liquid-liquid extraction.…”