Contrary to previous reports, cultures of Phanerochaete chrysosporium agitated on a gyrotory shaker degraded synthetic lignin to CO2 approximately as rapidly and extensively as static cultures. Agitated cultures also degraded the lignin in aspen wood to CO2 and water-soluble products as well as static cultures, if the wood particles became enmeshed in the mycelium. An atmosphere of oxygen stimulated lignin degradation, compared with air, in both agitated and static cultures. The mycelia in agitated cultures with ligninolytic activity formed single, large pellets.