Molecular insights into enhanced nitrogen removal induced by trace fluoroquinolone antibiotics in an anammox system

• Published in: Bioresource technology 2023-04, Vol.374, p.128784-128784, Article 128784
• Main Authors: Qiao, Xuejiao, Fu, Chenkun, Chen, Yizhen, Fang, Fang, Zhang, Yaoyu, Ding, Lingyun, Yang, Kai, Pan, Baozhu, Xu, Nan, Yu, Ke, Tao, Huchun, Zhang, Lijuan
• Format: Article
• Language: English
• Subjects: Ammonium Compounds - metabolism; Anaerobic Ammonia Oxidation; Anaerobic ammonium oxidation; Anaerobiosis; Anti-Bacterial Agents - metabolism; Bacteria - metabolism; Bioreactors - microbiology; Denitrification; Dissimilatory nitrate reduction to ammonium; Fluoroquinolone antibiotics; Fluoroquinolones - metabolism; Metabolomics; Metagenomics; Nitrogen - metabolism; Oxidation-Reduction
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2023.128784

[Display omitted] •The nitrogen removal was promoted by 20 μg/L FQs in an anammox system.•Simultaneous removal of FQs was achieved with an average efficiency of 36–51%.•Metagenomic analysis revealed three dominant MAGs belonging to AnAOB.•Enzymes were more active in nitrite reduction and hydrazine dehydrogenation.•Core metabolism and biosynthesis were up-regulated in anammox consortia. It has been widely reported that fluoroquinolones (FQs) can affect the anaerobic ammonium oxidization (anammox) microorganisms, which interferes with the performance of nitrogen removal from wastewater. However, the metabolic mechanism of anammox microorganisms responding to FQs has rarely been explored. In this study, it was found that 20 μg/L FQs promoted the nitrogen removal performance of anammox microorganisms in batch exposure assays, and 36–51% of FQs were removed simultaneously. Combined metabolomics and genome-resolved metagenomic analysis revealed up-regulated carbon fixation in anammox bacteria (AnAOB), while purine and pyrimidine metabolism, protein generation and transmembrane transport were enhanced in AnAOB and symbiotic bacteria by 20 μg/L FQs. Consequently, hydrazine dehydrogenation, nitrite reduction, and ammonium assimilation were bolstered, improving the nitrogen removal efficiency of the anammox system. These results revealed the potential roles of specific microorganisms in response to emerging FQs and provided further information for practical application of anammox technology in wastewater treatment.