Related Experiment Video
Updated: May 18, 2026

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
Published on: October 7, 2020
A heterotrophic nitrification and aerobic denitrification strain capable of antibiotic degradation: From function to
Jia-Ying Li1, You-Wei Cui1, Yuan Sui1
1National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing, 100124, China.
Abstract:
Amoxicillin is one of the most prevalent antibiotics found in wastewater treatment plants (WWTPs). It remains unknown which species of microorganisms in WWTPs can degrade amoxicillin. In this study, a novel heterotrophic nitrification and aerobic denitrification (HN-AD) strain with the ability of amoxicillin degradation was isolated from a local WWTP, designated Klebsiella oxytoca TY. This strain exhibited strong adaptability to various environmental factors, including different nitrogen (N) sources, pH and temperatures. Single N source experiments showed that the removal efficiencies of NH4+-N, NO3--N and NO2--N were 100%, 90.60% and 73.44%, respectively. Multiple functional genes involved in N metabolism were identified in the strain, establishing complex N removal pathways involving NH4+-N assimilation, HN-AD and NO3--N reduction. TY co-metabolized with sodium citrate to degrade amoxicillin. Amoxicillin was primarily removed through biodegradation (64.56%), companying with NH4+-N removal efficiency of 92.78% without NO3--N and NO2--N accumulation. The identification of amoxicillin intermediates suggested that the primary reaction sites for amoxicillin degradation were the beta-lactam ring, the thiazolidine ring and the C-N bond. Genome analysis also revealed that the TY strain contains the unique blaOXY gene of Klebsiella oxytoca, which encodes a beta-lactamase to remove amoxicillin. The results indicated that TY holds potential as a key microorganism to degrade amoxicillin in WWTPs and to perform aerobic N removal via HN-AD. This work enriches our knowledge reserve of novel microorganisms in WWTP.
Related Concept Videos
Metabolism of Chemolithotrophs
Microbial Nutrition
Production of Antibiotics
Inorganic Nitrogen Assimilation
Environmental Applications of Microorganisms
Deep Sea Microbial Ecology

