Lignins from three nonwoody angiosperms were analyzed by 2D NMR revealing important differences in their molecular structures. The Musa textilis milled-wood-lignin (MWL), with a syringyl-to-guaiacyl (S/G) ratio of 9, was strongly acylated (near 85% of side-chains) at the gamma-carbon by both acetates and p-coumarates, as estimated from (1)H-(13)C correlations in C(gamma)-esterified and C(gamma)...

Waterproofing of the aerial organs of plants imposed a big evolutionary step during the colonization of the terrestrial environment. The main plant polymers responsible of water repelling are lipids and lignin, which play also important roles in the protection against biotic/abiotic stresses, regulation of flux of gases and solutes, and mechanical stability against negative pressure, among othe...

Ball-milled bamboo (Neosinocalamus affinis) was first treated under ultrasound at 20 C in 95% ethanol solution for 0 to 50 min, dissolved in sodium hydroxide/urea solution (7% NaOH/12% urea) at –12 C, and then extracted with ethanol and dioxane to isolate lignin. The structure of the isolated lignin was characterized with a set of wet chemical and spectroscopic methods, including UV, FT-IR, C N...

RATIONALE Milling of wood samples is a widely applied preparation method for pooling tree-rings from different trees or periods of several years for determination of δ(13)C and δ(18)O values. In this study, whole wood samples were milled using different procedures in order to evaluate potential effects of this preparation method on δ(13)C and δ(18)O values. METHODS Subsamples of a 5 cm(3) woo...

BACKGROUND The valorization of biomass for chemicals and fuels requires efficient pretreatment. One effective strategy involves the pretreatment with ionic liquids which enables enzymatic saccharification of wood within a few hours under mild conditions. This pretreatment strategy is, however, limited by water and the ionic liquids are rather expensive. The scarce understanding of the involved ...

Betula platyphylla Suk (birch) is a fast-growing woody species that is important in pulp industries and the biofuels. However, as an important pulp species, few studies had been performed on its wood formation. In the present study, we investigated the molecular responses of birch xylem to artificial bending and gravitational stimuli. After trunks of birch trees were subjected to bending for 8 ...

Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light-transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30 wt % of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time c...

The penetration of enzymes into wood cell walls during white rot decay is an open question. A postembedding immunoelectron microscopic technique was the method of choice to answer that question. Infiltration of pine wood specimens with a concentrated culture filtrate greatly improved the labeling density and, thereby, reproducibility. Characterization of the concentrated culture filtrate by sod...

Soils and decayed plant litter contain significant quantities of chlorinated aromatic polymers that have a natural but largely unknown origin. We used cupric oxide ligninolysis coupled with gas chromatography/mass spectrometry to show that Curvularia inaequalis, a widely distributed litter ascomycete, chlorinated the aromatic rings of lignin in wood that it was degrading. In aspen wood decayed ...

This thesis describes studies with three different Norway spruce cutting clones in three growing environments differing in soil and climatic conditions within the boreal zone. The main aim was to follow variation in the radial growth rate, wood properties and lignin content and to modify wood lignin with a natural monolignol, coniferyl alcohol, by making use of inherent wood peroxidases. In add...