The antimicrobial and preservative agent triclosan (TCS) is an emerging and persistent pollutant with a ubiquitous presence in the aquatic environment. Thus. TCS was treated with manganese peroxidase (MnP), laccase and the laccase-mediator system with 1-hydroxybenzotriazole. MnP was most effective in eliminating TCS among the three enzymatic treatments, with TCS concentration being reduced by about 94% after 30 min following treatment with 0.5 nkat mL(-1) MnP and being almost completely eliminated after 60 min. Furthermore, MnP (0.5 nkat mL(-1)) caused the complete loss of bacterial growth inhibition by TCS after 30 min and reduced the algal growth inhibition of TCS by 75% and 90% after 30 and 60 min, respectively. These results strongly suggest that MnP is effective in removing the ecotoxicity of TCS. (C) 2010 Elsevier B.V. All rights reserved.