Lead-induced oxidative stress and antioxidant response provide insight into the tolerance of Phanerochaete chrysosporium to lead exposure

The present work investigated the effect of lead (Pb) on the growth, metal accumulation, oxidative stress, and antioxidant response in Phanerochaete chrysosporium, which is a well-known hyperaccumulating species for heavy metal with appreciable bioaccumulation capacity. Results revealed that P. chrysosporium exhibited a good ability in Pb accumulation and tolerance over a concentration range of 50-100 mg L-1 Pb. The removal rate of Pb decreased with the increasing levels of Pb and reached a maximum of 91.3% at 50 mg L-1. Both extracellular adsorption and intracellular bioaccumulation contributed to the removal of Pb, with the maximum of 123.8 mg g(-1) and 162.5 mg g(-1) dry weight, respectively. Pb may exert its toxicity to P. chrysosporium by impairing oxidative metabolism, as evidenced by the enhanced accumulation of hydrogen peroxide (H2O2) and lipid peroxidation product malonaldehyde (MDA). P. chrysosporium evolved an antioxidant system by elevating the activity of superoxide dismutase (SOD) and the level of reduced glutathione (GSH) in response to Pb stress, whereas decreasing the activities of catalase (CAT) and peroxidase (POD). Moreover, Pearson correlation analysis" demonstrated a good correlation between oxidative stress biomarkers and enzymatic antioxidants. The preset work suggested that P. chrysosporium exhibited an outstanding accumulation of Pb and tolerance of Pb-induced oxidative stress by the effective antioxidant defense mechanism. (C) 2017 Elsevier Ltd. All rights reserved.