Production of lignin modifying enzymes by co-cultivated White-rot fungi Cerrena maxima and Coriolus hirsutus and characterization of laccase from Cerrena maxima

Abstract

The lignin modifying enzymes production by co-cultivated C. hirsutus and Cerrena maxima, pure fungal cultures Coriolus hirsutus and Cerrena maxima in defined medium under static and shaken conditions, in media with birch sawdust and sulfonate lignin and under SSF of birch sawdust was comparatively studied. Analysis of the structure of residual lignin before and after fungal treatment indicated that the oxidation of phenolic component of lignin occurred and the residual lignin is enriched in carboxylic acid groups. Three laccase isoenzymes are produced by Cerrena maxima growing in defined media. The isoenzyme with pI 3.5 was largely present and its molecular mass, isoelectric point, metal content and carbohydrate composition were determined. The laccase was characterized to have a broad substrate specificity. It belongs to high redox potential laccases (750 mV vs. normal hydrogen electrode) and might be useful in industrial applications.