Biomechanical Pulping Of Aspen Chips By <i>Phanerochaete Chrysosporium</i>: Fungal Growth Pattern And Effects On Wood Cell Walls


  • Irving B. Sachs
  • Gary F. Leatham
  • Gary C. Myers


Phanerochaete chrysosporium Burds, white-rot fungi, basidiomycetes, biopulping, aspen wood, wood degradation, fungal bore holes, erosion troughs, cell-wall degradation


Evaluation of the potential of biopulping requires a better understanding of its physical and chemical basis. Here we investigate the fungal treatment used on wood chips prior to mechanical pulping in a bench-scale biomechanical pulping process currently under study. Scanning electron microscopy was used to observe fungal growth and the degradation of nutrient-supplemented aspen chips after a 3-week treatment with the white-rot basidiomycete Phanerochaete chrysosporium strain BKM-F-1767. The fungus grew well both across the chip surfaces and throughout the wood cells. The fungus penetrated the chips through the lumina of wood vessel and fiber cells as well as through natural wood cell pits and fungal bore holes. Partial degradation of the cell lumen walls by secreted fungal enzymes was evident. Erosion troughs and localized wall fragmentation or thinning were clearly visible as was a generalized swelling and relaxing of the normally rigid wood cell wall structure.


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