Simultaneous aerobic denitrification and antibiotics degradation by strain Marinobacter hydrocarbonoclasticus RAD-2

• Published in: Bioresource technology Vol. 313; p. 123609
• Main Authors: Ruan, Yunjie, Kumar Awasthi, Mukesh, Cai, Lei, Lu, Huifeng, Xu, Xiangyang, Li, Wenbing
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2020
• Subjects: Aerobic denitrification; Antibiotics degradation; ciprofloxacin; denitrification; Denitrifying gene expression; hormesis; Marinobacter hydrocarbonoclasticus; N2O production; nitrates; nitrous oxide; oxytetracycline; Strain growth characteristics; technology; transcription (genetics); Denitrifying gene expression; Antibiotics degradation; Aerobic denitrification; Strain growth characteristics; N2O production
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2020.123609

[Display omitted] •Aerobic denitrification and antibiotics degradation was gained in strain RAD-2.•No significant influence on denitrification performance with antibiotics shock.•Insignificant inhibiting effect on strain growth under antibiotics dosage.•Antibiotics triggered significant time-lapse up-regulation of denitrifying genes.•Less N2O productions were founded in denitrification process with antibiotics. Simultaneous denitrification and antibiotics (oxytetracycline, OTC and ciprofloxacin, CFX) degradation was evaluated using a typical aerobic denitrifying strain Marinobacter hydrocarbonoclasticus RAD-2. There was no significant influence on the aerobic nitrate removal efficiency of strain RAD-2 in the presence of these two antibiotics. Along with denitrification, the average degradation rate of 2.92 μg OTC L−1h−1 was achieved, while no degradation was observed for CFX. The growth behavior indicated that an insignificant inhibition effect could have occurred at an antibiotics dosage lower than 300 μg/L. The transcriptional results revealed that antibiotics exposure caused (<2h) down-regulation of the denitrifying related genes, but triggered a significant subsequent up-regulation (4 h). Less nitrous oxide productions were observed in both aerobic and anoxic denitrification processes with antibiotics. Overall, the hormesis effect caused by antibiotics exposure indicated a potential approach to enhance the co-metabolism degradation performance for nitrate and antibiotics in aerobic denitrification.