Alteration of culture fluid proteins by cadmium induction in Phanerochaete chrysosporium

Microorganisms need to resist the hazards posed by heavy metals during the process of metal adsorption. Phanerochaete chrysosporium is a fungus that is efficiently used for heavy-metal biosorption in wastewater treatment. Extraction and analysis of proteins induced by heavy metals can help to understand the regulatory mechanisms of P. chrysosporium in wastewater treatment. In this study, P. chrysosporium was exposed to 50 μM cadmium nitrate. A maximum cadmium adsorption capability of 77.1 mg/g dry biomass was found after 65 h, which was accompanied by a relatively higher protein concentration. After separation of the culture fluid proteins by two-dimensional difference gel electrophoresis (2D-DIGE), three differentially expressed proteins were detected from 17 spots. By using 2D-DIGE, followed by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS), glutathione S-transferase, glyceraldehyde-3-phosphate dehydrogenase, and malate dehydrogenase were identified. All three enzymes play important roles in the oxidative stress caused by cadmium.