The production of lignin-degrading enzymes by free and entrapped cells ofPhanerochœte chrysosporium in a tubular air-lift bioreactor was studied. Under optimized cultural conditions the production of lignin peroxidase by free cells, calcium-alginate-entrapped cells and scouring-mesh-entrapped cells was in a ratio of 520∶720∶950 mU/mL, while the production of manganese peroxidase was in a ratio of 350∶480∶620 mU/mL. The stability of the entrapped cells by fed-batch systems was highest after 3 feeding experiments which is similarly demonstrated in the repeated use of the preparations in batch system.