Immobilization of laccase from Cerrena unicolor on controlled porosity glass

White-rot basidiomycete Cerrena unicolor grown in non-induced and induced c onditions was tested for production of laccase, lignin peroxidase (LiP) and manganese-dependent peroxidase (MnP). A typical correlation between the co ncentration of phenolic compounds in the culture fluid and the extracellula r laccase activity was observed. The heterogeneous crude laccase preparatio n obtained after the non-induced fermenter cultivation was immobilized both on controlled porosity glass (CPG) activated by gamma-aminopropyltriethoxy silane (APTES) and on CPG with its surface covered by dextran layers. The l accase activities were tested in the aqueous solution for the native and im mobilized preparations using different pH and temperature conditions. Lacca se activities were additionally examined for native and immobilized forms o f laccase preparations in the aqueous solution containing organic solvents. The greatest activity toward the substrate used in the presence of organic solvents was shown by the laccase preparation coupled with the CPG covered by a dextran layer. Potential inhibitors such as thioglycolic acid, thiour ea and EDTA used in 1-mM concentration did not show inhibiting properties t owards the laccase preparations. (C) 1999 Elsevier Science B.V. All rights reserved.