Mechanisms of Lignin Degradation with Three Species of Enzymes(Systems)

The shortcomings of lignin degradation by White rot fungi can be overcome by the application of laccase and xylanase. The pinus massoniana unbleached pulp was treated by xylanase, laccase/mediator system and laccase/xylanase system; the mechanisms of lignin degradation with three enzymes were discussed in this paper. Three species of enzymes (systems) have better ability of degradation of lignin and can improve the physical strengths of the pulp. The change of the pulp chemical composition after the treatment by three species of the enzymes (systems) indicated that, laccase has better lignin degradation ability and better selectivity for lignin degradation compared with xylanase. The analyses of FT-IR spectrum and SEM further proved the delignification function of laccase therefore laccase/xylanase system can completely replace the complex and expensive laccase/mediator system to be used for biopulping and biobleaching.