Comparison of the dynamic responses of different anammox granules to copper nanoparticle stress: Antibiotic exposure history made a difference. (August 2021) - Fu, Jin-Jin
Graphical abstract: Highlights: The responses of two different anammox granules to CuNPs were investigated. Antibiotic-exposed anammox granules were more sensitive to the CuNPs stress. CuNPs induced the co-selection of multiple resistance genes in the anammox system. The mechanism through which CuNPs affected the anammox granules was speculated. Abstract: Two types of anaerobic ammonium oxidation (anammox) seed sludge were selected to evaluate their responses to copper nanoparticles (CuNPs) exposure. Antibiotic-exposed anammox granules (R1 ) were more likely to be inhibited by 5.0 mg L -1 CuNPs than the normal anammox granules (C1 ). The nitrogen removal efficiency (NRE) of C1 decreased by 9.00% after two weeks of exposure to CuNPs, whereas that of R1 decreased by 20.32%. Simultaneously, the abundance of Candidatus . Kuenenia decreased by 27.65% and 36.02% in C1 and R1 under CuNPs stress conditions, respectively. Generally, R1 was more susceptible to CuNPs than C1 . The correlation analysis indicated that the horizontal transfer of antibiotic resistance genes and cop A triggered by int I1 facilitated the generation of multiresistance in the anammox process. Moreover, the potential multiresistance mechanism of anammox bacteria was hypothesized based on previous results. The results will generate new ideas for the treatment of complex wastewater using the anammox process.