Biomaterial Database

Enzymatic polymerisation and effect of fractionation of dissolved lignin from Eucalyptus globulus Kraft liquor. 2012

S Gouveia, and C Fernández-Costas, and M A Sanromán, and D Moldes

Department of Chemical Engineering, University of Vigo, Lagoas Marcosende s/n, E-36310 Vigo, Spain.

The potential ability of the laccase from Myceliophthora thermophila, either alone or with low molecular weight (LMW) additives, to polymerise a dissolved lignin from Kraft liquor of eucalypt cooking was investigated. A previous study of enzymatic performance (activity and stability) was carried out using a design experiment methodology. In addition, Kraft dissolved lignin (KDL) was fractionated according to two different protocols (solvent extraction and acidic fractionation) in order to identify possible lignin fractions with noticeable polymerisation ability. KDL and its corresponding lignin fractions were treated with laccase and analysed by size exclusion chromatography and Fourier transform infrared spectroscopy. The results provide conclusive evidence of notable lignin modifications after incubation with laccase. Moreover, lignin fractionation allows to obtain lignin fractions with different chemical characteristics and polymerisation capability. Depending on the type of raw lignin, molecular weight can increase from 4- to 21-fold by means of laccase polymerisation.

UI	MeSH Term	Description	Entries
D008031	Lignin	The most abundant natural aromatic organic polymer found in all vascular plants. Lignin together with cellulose and hemicellulose are the major cell wall components of the fibers of all wood and grass species. Lignin is composed of coniferyl, p-coumaryl, and sinapyl alcohols in varying ratios in different plant species. (From Merck Index, 11th ed)	Lignins
D002850	Chromatography, Gel	Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.	Chromatography, Exclusion,Chromatography, Gel Permeation,Chromatography, Molecular Sieve,Gel Filtration,Gel Filtration Chromatography,Chromatography, Size Exclusion,Exclusion Chromatography,Gel Chromatography,Gel Permeation Chromatography,Molecular Sieve Chromatography,Chromatography, Gel Filtration,Exclusion Chromatography, Size,Filtration Chromatography, Gel,Filtration, Gel,Sieve Chromatography, Molecular,Size Exclusion Chromatography
D005052	Eucalyptus	A genus of trees of the Myrtaceae family, native to Australia, that yields gums, oils, and resins which are used as flavoring agents, astringents, and aromatics.	Blue Gum Tree,Bluegum Eucalyptus,Eucalyptus globulus,Blue Gum Trees,Eucalyptus, Bluegum,Gum Tree, Blue,Gum Trees, Blue,Tree, Blue Gum,Trees, Blue Gum
D005591	Chemical Fractionation	Separation of a mixture in successive stages, each stage removing from the mixture some proportion of one of the substances, for example by differential solubility in water-solvent mixtures. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Fractionation, Chemical,Chemical Fractionations,Fractionations, Chemical
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D017550	Spectroscopy, Fourier Transform Infrared	A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.	FTIR,Fourier Transform Infrared Spectroscopy,Spectroscopy, Infrared, Fourier Transform
D042845	Laccase	A copper-containing oxidoreductase enzyme that catalyzes the oxidation of 4-benzenediol to 4-benzosemiquinone. It also has activity towards a variety of O-quinols and P-quinols. It primarily found in FUNGI and is involved in LIGNIN degradation, pigment biosynthesis and detoxification of lignin-derived products.	Laccase B,Laccase I,Laccase II,Laccase III,Urishiol Oxidase,p-Diphenol Oxidase,Oxidase, Urishiol,Oxidase, p-Diphenol,p Diphenol Oxidase
D058105	Polymerization	Chemical reaction in which monomeric components are combined to form POLYMERS (e.g., POLYMETHYLMETHACRYLATE).	Polymerizations
D020037	Sordariales	An order of fungi in the phylum ASCOMYCOTA that includes many valuable experimental organisms. There are eight families and very few anamorphic forms.	Sordariale