The Root-rot fungus, Heterobasidion annosum, is one of the worst among forest pathogens, estimated to account for an economic loss of €790 million for the area of the European Union (in 1998; Woodward et al., 1998). The genome of H. annosum has recently been sequenced and a total of ~280 carbohydrate-active enzymes have been predicted so far. The fungus is apparently an efficient wood degrader and may produce enzymes of interest for enzymatic saccharification of cellulose for biofuel production. The aim of this study was to see which major enzymes that are expressed and utilized. The strain that was sequenced, H. annosum TC-32-1, was grown in minimal medium with different lignocelluloses as carbon source. Extracellular proteins from one culture with spruce as carbon source were detected in electrophoresis after separation by cation and anion exchange chromatography. Proteins were identified by tryptic peptide mapping using MALDI-TOF mass spectrometry. We have identified 15 proteins so far which included 1 polysaccharide lyase, 10 glycoside hydrolases and 4 hypothetical proteins. Cellulase activity measurements were carried out using p-hydroxybenzoic acid hydrazide (PHBAH) as reagent for reducing sugar. One Cel7 enzyme was identified as the most expressed protein, and showed the highest cellulase activity. Enzyme characterisation is underway.

Woodward et al., 1998 In: S. Woodward, J. Stenlid, R. Karjalainen and A. Hüttermann, Editors, Heterobasidion annosum—Biology, Ecology, Impact and Control, CAB International, Wallingford, UK (1998), p. 589