Chemical immobilization of Trichosporon cutaneum R57 cells onto modified polyacrylonitrile granules and fibres was carried out. The polymer carriers were modified in water solutions of NaOH and 1,2-diaminoethane. The concentration of amino groups obtained by the modification was determined. The optimal conditions for chemical immobilization of cells of T. cutaneum R57 with glutaraldehyde were found to be: 40% NaOH concentration, 46.8 mg/ml initial cell suspension, 24 h immobilization time and pH 6. The change in protein concentration of free and immobilized cells was studied during a full biodegradation cycle. The rate of phenol biodegradation by T. cutaneum R57 cells immobilized on porous polyacrylonitrile (PAN) fibres was higher than that obtained using modified PAN beds. (C) 2000 Elsevier Science Ltd. All rights reserved.