Reactivity of a Fungal Laccase Towards Lignin in Softwood Kraft Pulp
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M. Lund
Summary
The reactivity of a fungal laccase to lignin of six different spruce kraft pulps with kappa numbers ranging from 15 to 110 was studied. Enzymatic oxidation of lignin was investigated by monitoring the oxygen consumption in a suspension of the pulp and the number of radicals generated in the pulp, as measured by electron paramagnetic resonance spectroscopy. The laccase catalyzed oxidation of lignin in kraft pulp followed a double exponential function. This indicates the presence of two types of substrates oxidized by the enzyme at different rates. The two substrates were interpreted as lignin located on the surface of the pulp fibers and as lignin in the cell wall. A linear relationship was found between the kappa number of the pulps and the observed first-order rate constant for oxidation of substrate in the cell wall. Quantification of free radicals in the pulp showed a linear dependence on the lignin content and the number of free radicals generated upon oxidation with laccase.
Copyright © 2003 by Walter de Gruyter GmbH & Co. KG
Articles in the same Issue
- The Relationship Between Variability of Cell Wall Mass of Earlywood and Latewood Tracheids in Larch Tree-Rings, the Rate of Tree-Ring Growth and Climatic Changes
- How Variability in OSB Mechanical Properties Affects Biological Durability Testing
- Microfibril Angles Inside and Outside Crossfields of Norway Spruce Tracheids
- Reactivity of a Fungal Laccase Towards Lignin in Softwood Kraft Pulp
- Lignans and Lipophilic Extractives in Norway Spruce Knots and Stemwood
- Investigation of Lignin Oligomers Using Electrospray Ionisation Mass Spectrometry
- Reactions of Lignin with Peroxymonophosphoric Acid: The Degradation of Lignin Model Compounds
- The Reactions of Lignin Model Compounds with Hydrogen Peroxide at Low pH
- Spin Distribution in Dehydrogenated Coniferyl Alcohol and Associated Dilignol Radicals
- Ultrastructural Localisation of Glucomannan in Kraft Pulp Fibres
- New Method for Quantitative Preparation of Lignin- Carbohydrate Complex from Unbleached Softwood Kraft Pulp: Lignin-Polysaccharide Networks I
- Peroxide Bleaching of Parquet Blocks and Glue Lams
- Easily Degradable Chlorinated Compounds Derived from Glucuronoxylan in Filtrates from Chlorine Dioxide Bleaching of Eucalyptus globulus Kraft Pulp
- Non-Deterministic Description of Wood Radio Frequency Vacuum Drying
- Bending Creep of High-Temperature Dried Spruce Timber
- Optimization of a Violin Top with a Combined Laminate Theory and Honeycomb Model of Wood
- Optimisation of Soda Pulping Variables for Preparation of Dissolving Pulps from Oil Palm Fibre
Articles in the same Issue
- The Relationship Between Variability of Cell Wall Mass of Earlywood and Latewood Tracheids in Larch Tree-Rings, the Rate of Tree-Ring Growth and Climatic Changes
- How Variability in OSB Mechanical Properties Affects Biological Durability Testing
- Microfibril Angles Inside and Outside Crossfields of Norway Spruce Tracheids
- Reactivity of a Fungal Laccase Towards Lignin in Softwood Kraft Pulp
- Lignans and Lipophilic Extractives in Norway Spruce Knots and Stemwood
- Investigation of Lignin Oligomers Using Electrospray Ionisation Mass Spectrometry
- Reactions of Lignin with Peroxymonophosphoric Acid: The Degradation of Lignin Model Compounds
- The Reactions of Lignin Model Compounds with Hydrogen Peroxide at Low pH
- Spin Distribution in Dehydrogenated Coniferyl Alcohol and Associated Dilignol Radicals
- Ultrastructural Localisation of Glucomannan in Kraft Pulp Fibres
- New Method for Quantitative Preparation of Lignin- Carbohydrate Complex from Unbleached Softwood Kraft Pulp: Lignin-Polysaccharide Networks I
- Peroxide Bleaching of Parquet Blocks and Glue Lams
- Easily Degradable Chlorinated Compounds Derived from Glucuronoxylan in Filtrates from Chlorine Dioxide Bleaching of Eucalyptus globulus Kraft Pulp
- Non-Deterministic Description of Wood Radio Frequency Vacuum Drying
- Bending Creep of High-Temperature Dried Spruce Timber
- Optimization of a Violin Top with a Combined Laminate Theory and Honeycomb Model of Wood
- Optimisation of Soda Pulping Variables for Preparation of Dissolving Pulps from Oil Palm Fibre
