BIOMECHANICAL PULPING OF LOBLOLLY-PINE CHIPS WITH SELECTED WHITE-ROT FUNGI

Loblolly pine chips were treated with several white-rot fungi in two different bioreactor configurations for four weeks prior to refiner mechanical pulping. Irrespective of the bioreactor configuration, all fungal treatments caused some chip weight loss and saved electrical energy during fiberization and refining as compared to the untreated control. Some of the fungal treatments improved strength properties of the handsheets, whereas brightness and light scattering coefficient of the handsheets were decreased after all of the fungal treatments. Opacity of the handsheets after the fungal treatments remained unchanged. Based on energy savings and improvements in the strength properties, regardless of bioreactor type, the white-rot fungus Ceriporiopsis subvermispora appeared to be superior to the other white-rot fungi tested. When incubated in stationary tray bioreactors, C. subvermispora caused only 6% weight loss, saved 42% energy during fiberization and refining, improved burst index by 32% and tear index by 67%, as compared to the control.