Transcriptional expressions of Nitrosomonas europae after CeO2 nanoparticle exposure and 12-h recovery

To further explore the biotoxicity mechanisms of CeO2 nanoparticles (NPs) and the recovery strategies of the according impaired Nitrosomonas europaea (N. europaea, ATCC 19718) cells, a genome-sequenced model ammonia oxidizing bacterium (AOB) commonly detected in the activated sludge of biological wastewater treatment plants, the whole-genome microarray analysis was applied to retrieve the induced transcriptional responses, after their physiological and metabolic activities were evealed. The whole-genome expressions were measured after exposure to 50 ppm CeO2 NPs and 12-hr recovery incubation when the ammonia removal rate (ARA) declined by 10% in the chemostat bioreactor .Three biological replicates were included for exposure and recovery experiment.