Degradation of tetracycline and oxytetracycline by crude lignin peroxidase prepared from Phanerochaete chrysosporium--a white rot fungus.

Pharmaceuticals are becoming an emerging environmental issue that attracts increasing attention in recent years. This study chose tetracycline (TC) and oxytetracycline (OTC) as examples of pharmaceuticals. Crude lignin peroxidase (LiP) produced by Phanerochaete chrysosporium were used to degrade TC and OTC in vitro. The results illustrated that LiP has a strong degrading ability towards TC and OTC. At 50 mgL(-1) of TC and OTC and 40 UL(-1) of the enzyme activity, the degradation of TC and OTC reached to about 95% in 5 min. The degradation of TC and OTC by LiP was dependent on pH and temperature and was largely enhanced by increasing the concentrations of veratryl alcohol (VA) and initial hydrogen peroxide (H2O2). The optimized degradation conditions were determined as pH 4.2, 37 degrees C, 2 mM VA, 0.4 mM H2O2.