Impacts of erythromycin antibiotic on Anammox process: Performance and microbial community structure

The occurrence and accumulation of antibiotics in wastewater treatment plant have been a growing concern. Erythromycin (ERY), a representative class of Macrolides, was picked out to investigate the long-term effects on anaerobic ammonium oxidation (Anammox) process in this study. Anaerobic ammonia-oxidizing bacteria (AAOB) was initially inhibited when suffered the ERY in 0.001 and 1 mg L−1, but rapidly recovered after 12 and 10 days’ exposure, respectively. The restoration time of AAOB under the stress of ERY in 1 mg L-1 was shorter than that in 0.001 mg L−1. Significant suppression without recovery was observed as the concentration of ERY was increased to 10 mg L−1. The deterioration was continued with the increasing concentrations. However, the pace of deterioration was tended to ease in each phase. Therefore, it can be speculated that Anammox microorganisms resisted the biotoxicity of ERY to some extent via gene mutations or secreted more extracellular polymeric substances.