Liisa Viikari*, Tapani Reinikainen and Matti Siika-aho

VTT Biotechnology, Espoo, Finland

VTT Biotechnology, P.O. Box 1500; FIN-02044 VTT
Phone: +358 9 456 5104

Fax +358 9 455 2103

E-mail: Liisa.Viikari@vtt.fi

It is well recognized that efficient hydrolysis of cellulose requires the synergistic action of all major cellulases: cellobiohydrolases, endoglucanases and ß-glucosidases. Lignocellulosic raw materials are, however, complex substrates composed, in addition to cellulose, also of hemicellulose and lignin. During the pretreatment steps, the structure and composition is modified in order to make cellulose more amenable to enzymatic hydrolysis. The enzymatic hydrolysis of cellulose can be improved by increasing the specific activity, functionality and stability of cellulases, by designing more optimal cellulase mixtures, by improving the enzyme production systems and by optimizing hydrolysis techniques. Less attention has been paid to the role of other enzymes hydrolysing or modifying lignin and hemicellulose. This paper describes recent results in the enzymatic modification of hemicellulose and lignin in order to improve the total hydrolysis of lignocellulosic raw materials.