Performance of Aerobic Denitrification by the Strain Pseudomonas balearica RAD-17 in the Presence of Antibiotics.

Yunjie Ruan,Meng Zhang,Xiangyang Xu,Huifeng Lu,Lei Cai,Wenbing Li

doi:10.3390/microorganisms9081584

Abstract

Aerobic denitrification, one of the important nitrate metabolic pathways in biological denitrification, has been attracting increasing interest recently due to its functional advantages. In order to evaluate the effect of antibiotics on aerobic denitrification and guide practical engineering application of aerobic denitrification techniques, we evaluated the performance of aerobic denitrification by the strain Pseudomonas balearica RAD-17 in the presence of ciprofloxacin (CFX) and oxytetracycline (OTC). No significant negative impact on the performance of aerobic denitrification in the presence of CFX or OTC within the range of 50 to 300 μg L−1 was found. Significant degradation of OTC was found within the range of 50 μg L−1 to 300 μg L−1 under aerobic denitrification conditions, while no degradation was found for CFX. Stimulation of cell growth occurred within the investigated range of antibiotics. Under anoxic or aerobic conditions, the addition of CFX or OTC changed the N2O production trend. The results in the present study may play an important role in informing the use of aerobic denitrification techniques in the presence of antibiotics within environmentally relevant concentrations (<1 mg/L).

Highlights

Denitrification is a crucial process for nitrogen cycling process in ecosystems, especially for the removal of nitrogen from wastewater [1]
In the presence of CFX, there were no significant impacts on the aerobic denitrification performance of strain RAD-17 within the range of 50 μg L−−11 to 300 μg L−−11 (Figure 1A)
The nitrate removal efficiency varied from 92.57 ± 0.75% to 95.27 ± 1.67%, which was similar to nitrate removal efficiency varied from 92.57 ± 0.75% to 95.27 ± 1.67%, which was similar the results obtained without average to the results obtained withoutCFX

Summary

Introduction

Denitrification is a crucial process for nitrogen cycling process in ecosystems, especially for the removal of nitrogen from wastewater [1]. Denitrification mediated by microorganisms is usually considered as a process under anoxic conditions, since the gene encoded for nitrate reductase is sensitive for oxygen [2]. Due to its functional advantages, aerobic denitrification is an important nitrate metabolic pathway for biological denitrification and has been paid more attention by scientists [4]. Compared to anoxic denitrifying microbe, a gene cluster of napFDAGHBC was found in aerobic denitrifying microbe, and this made the nitrate removal process for aerobic denitrifying microbe is different from anoxic denitrifying microbe [5]. There will be a wider niche and fitness for aerobic denitrification process than anaerobic denitrification process

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Discussion

Conclusion