ENZYMATIC ACTIVATION OF WOOD FIBERS AS A MEANS FOR THE PRODUCTION OF WOOD COMPOSITES

The incubation of wood fibres with a phenoloxidase (laccase) results i n the oxidation of the lignin crust on the fibre surface which finally is released from the fibre surface into the incubation medium. During this reaction, the lignin is highly oxidized, as can be seen from its high carboxyl content. When fibres treated with the enzyme are presse d together under conditions usually employed during the process of mak ing fibre boards, boards are obtained which meet the required standard s for German medium density fibre board (MDF). The enzymatically activ ated fibres in the wood composites made by this process are bound toge ther in a way which is closer to the situation in the naturally grown wood than any other process used today in the present production of wo od composites.