Transformation of Chlorophenols by White-Rot Fungi and their Laccase

Summary

The effects of pentachlorophenol (PCP) and 2-chlorophenol (2CP) on white rot fungi, Abortiporus biennis, Cerrena unicolor, Gloeophyllum odoratum, and Trametes versicolor were investigated. With the exception of C. unicolor and A. biennis, concentrations of PCP higher than 50 ppm inhibited fungal growth completely. However, extreme concentrations of PCP (500 ppm) caused a 61% increase in growth of C. unicolor compared to the control culture within 14 days. When initial PCP concentrations were 50 ppm A. biennis and C. unicolor achieved, respectively, 87% and 78% of chlorophenol transformation within 3 days. However, when 2,5-dimethylaniline (0.2mM) was added to the C. unicolor culture, 98% of PCP transformation was achieved after one hour. Under the same conditions, A. biennis transformed 44% of PCP. Both chlorophenols are completely removed, when laccase activity reaches its maximum. In conclusion, among the four fungi investigated, C. unicolor and A. Biennis were very effective in transforming PCP and 2-CP. This biotransformation was greatly intensified by 2,5-dimethylaniline and accompanied by an increase in laccase activity.