Semi-continuous production of laccase byPhlebia radiata in different culture media

The white-rot fungusPhlebia radiata, immobilized on a polypropylene carrier, was cultivated in a laboratory fermentor under semi-continuous conditions on culture media varying in the content of nitrogen, glucose, vitamins and microelements. Moreover, two laccase inducers were used: veratryl alcohol and veratraldehyde. Throughout the cultivation except the growth phase in the first cycle of fermentation, the observed rate of laccase expression reached up to about 2.0 nkat/mL per 1 h of cultivation, as determined by ABTS oxidation. In most experiments, phenol oxidase activity was determined also in the reaction with syringaldazine, giving reaction rates almost two times lower than in the case of ABTS.