Potential use of a white-rot fungus Antrodiella sp. RK1 for biopulping

A white-rot fungus Antrodiella sp. RK1 was evaluated for its use in biomechanical pulping process. After 4 weeks of pretreatment of aspen wood chips, electrical energy needed for fiberizing chips during mechanical pulping was reduced by about 26%. The burst, tear, tensile indices and fiber length were improved, whereas brightness, density and light scattering coefficient were reduced. Scanning electron micrographs showed that the fungus grew well, both on the chip surface as well as in its interiors. Localized thinning and fragmentation of the wood cell walls were clearly visible. Calcium crystals were found in association with hyphae in the eroded areas. Laccase was found to be the dominant enzyme in the extracts of the culture grown on mechanical pulp of aspen wood.