Biodegradation Characteristics of Pharmaceutical Substances by Whole Fungal Culture Trametes versicolor and its Laccase

Abstract

The degradation of 10 selected pharmaceutically active compounds (PhACs) by whole fungal culture Trametes versicolor, culture filtrates and commercial laccase preparation was conducted. Complete removal of diclofenac (DCF), naproxen (NPX), indomethacin (IDM), ibuprofen (IBP), and fenoprofen (FEP) and partial degradation of other selected PhACs were observed after 48 hours of incubation with the 7-day-old liquid fungal culture both in the presence and absence of ABTS (2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid)) as a laccase-mediator. The catalytic activity of laccase in the degradation of selected PhACs was examined for both crude and commercial extracellular laccase preparations. The results showed that laccase preferentially removed DCF, NPX and IDM among the target PhACs removed by the whole fungal culture. Intracellular enzymes may be involved in the degradation of ketoprofen (KEP), clofibric acid (CA), carbamazepine (CBZ), propyphenazone (PPZ), fenoprofen (FEP) and gemfibrozil (GFZ). The removal of most selected PhACs was increased with the increase in laccase activity. The presence of redox mediators such as ABTS and HBT (1-hyroxybenzotriazole) promoted the degradation of selected PhACs, in which complete removal of DCF, NPX and IDM was observed after 3 hours of incubation with laccase activity (2000 U/L) in the presence of ABTS/HBT. The degradation spectrum by laccase for ionic PhACs with nitrogen-containing structure was quite different from that of the activated sludge process.