Fungal treatment of aspen for wood resin reduction: effect on aged aspen wood chips at room temperature and at 5¥C.

A laboratory evaluation was conducted to study the effectiveness of a biotreatment for deresinating wood chips from aged aspen. This treatment involves inoculating chips with a fungal inoculum, Cartapip 97®, that feeds on wood resin components. This study demonstrated that, at room temperature and at 5°C, Cartapip can colonize chips from aged aspen despite the lower extractives content of the wood. Fungal treatment resulted in an additional 8% removal of wood resin in treated chips than in untreated chips after 3 weeks of seasoning. Analysis of the extractives by gas chromatography showed a significant reduction of steryl esters 125%), which are troublesome non-saponifiable wood resin components often found in aspen pitch deposits. The fungal treated chips were brighter than the untreated chips because the fungus prevented colonization of the chips by staining fungi. These results imply that fungal treatment of aspen chip piles in the winter will reduce the amount of wood resin in the chips and maintain their brightness. Such treatment will help alleviate pitch deposition problems attributable to aspen wax and reduce bleaching costs.