Effects of cadmium on calcium homeostasis in the white-rot fungus Phanerochaete chrysosporium

摘要

Due to the widespread application of white-rot fungi for the treatment of pollutants, its crucial to exploit the special effects of pollutants on the microbes. Here, we studied the effects of cadmium on calcium homeostasis in the most studied white-rot fungus Phanerochaete chrysosporium. The response of P. chrysosporium to cadmium stress is concentration-dependent. A high concentration of cadmium caused the release of calcium from P. chrysosporium, while a hormesis effect was observed at a lower cadmium concentration (10 mu M), which resulted in a significant increase in calcium uptake and reversed the decrease in cell viability. Calcium (50 mu M) promoted cell viability (127.2% of control), which reflects that calcium can protect P. chrysosporium from environmental stress. Real-time changes in the Ca2+ and Cd2+ fluxes of P. chrysosporium were quantified using the noninvasive microtest technique. Ca2+ influx decreased significantly under cadmium exposure, and the Ca2+ channel was involved in Ca2+ and Cd2+ influx. The cadmium and/or calcium uptake results coupled with the real-time Ca2+ and Cd2+ influxes microscale signatures can enhance our knowledge of the homeostasis of P. chrysosporium with respect to cadmium stress, which may provide useful information for improving the bioremediation process.