Bioremoval and Detoxification of Anthracene by a Halophilic Laccase from Alkalibacillus salilacus.

Abstract

Polycyclic Aromatic Hydrocarbons (PAHs) as resistant compounds in the environment has received much attention in recent years due to their adverse effects on ecological health. Among the various methods studying the removal of PAHs, enzyme biotechnology is one of the most effective and appropriate method. In the present study, a halophilic laccase was used for bioremoval of anthracene in the presence of 1-Hydroxybenzotriazole (HBT). Halophilic laccase from Alkalibacillus salilacus was tested for anthracene degradation. Residual concentration of anthracene at various concentrations of NaCl (0‒4 M), incubation time, pH, solvent, and surfactants in the enzymatic reaction mixtures was determined by HPLC. The maximum removal of substrate was achieved after 72 h at 40 °C, pH 8, and NaCl concentration 1.5 M. Besides, the addition of 1% (v/v) ionic and non-ionic surfactants and 25% (v/v) of various organic solvents increased removal efficiency. The kinetic parameters Km and Vmax of the laccase for removing of anthracene were 0.114 μM and 0.546 μmoL. h.-1 mg-1, respectively. Laccase showed the maximum removal efficiency of anthracene in the presence of 1-Hydroxybenzotriazole (HBT).