A study of the enzymatic degradation of triclosan

Triclosan and other antimicrobial compounds have become increasingly common in consumer products. With widespread use has come an increase in triclosan in waste water and biosolids. Studies have found triclosan to be toxic to fish and other aquatic life as well as a possible estrogen mimic in humans. There is also research showing that widespread use of antimicrobials may be contributing to an increase in antibiotic resistant organisms. This had made the removal of triclosan from waste water and biosolids a topic of interest. In this study four fungal enzymes were tested for their ability to transform triclosan. Any enzyme found to transform triclosan was tested in the presence of humic acid to better simulate conditions in natural water sources. Laccase, chloroperoxidase, manganese peroxidase, and lignin peroxidase were tested in conditions optimal for each enzyme. Laccase was found to successfully transform triclosan with a linear reduction in concentration over time. Some of the oxidation and degradation products were identified. The presence of humic acid was not found to have an effect on laccase activity with regards to triclosan. Chloroperoxidase, manganese peroxidase, and lignin peroxidase were not found to transform triclosan under the conditions tested.