Induction of Microbial Oxidative Stress as a New Strategy to Enhance the Enzymatic Degradation of Organic Micropollutants in Synthetic Wastewater

• Published in: Environmental science & technology 2019-08, Vol.53 (16), p.9553-9563
• Main Authors: Bains, Amrita, Perez-Garcia, Octavio, Lear, Gavin, Greenwood, David, Swift, Simon, Middleditch, Martin, Kolodziej, Edward P, Singhal, Naresh
• Format: Article
• Language: English
• Subjects: Abundance; Agricultural wastes; Anthropogenic factors; Aquatic organisms; Atrazine; Biodegradation; Biological activity; Biological wastewater treatment; Carbamazepine; Contaminants; Cytochrome; Cytochromes; Dairy farms; Dairy industry wastewaters; Degradation; Dissolved oxygen; Herbicides; Ibuprofen; Microorganisms; Micropollutants; Naproxen; Nonsteroidal anti-inflammatory drugs; Oxidative stress; Peroxidase; Perturbation; Pseudomonadaceae; Receiving waters; Redundancy; Sulfamethoxazole; Tylosin; Wastewater discharges; Wastewater treatment; Wastewater treatment plants; Water treatment
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/acs.est.9b02219

Organic micropollutants (OMPs) are pervasive anthropogenic contaminants of receiving waters where they can induce various adverse effects to aquatic life. Their ubiquitous environmental occurrence is primarily attributed to discharge from wastewater treatment plants due to incomplete removal by common biological wastewater treatment processes. Here, we assess a new strategy for promoting the degradation of six representative OMPs (i.e., sulfamethoxazole, carbamazepine, tylosin, atrazine, naproxen, and ibuprofen) by intentionally stimulating the production of microbial oxidoreductases to counter oxidative stress caused by oxygen perturbations. Mixed microbial cultures from a dairy farm wastewater were subjected to cyclic perturbations of dissolved oxygen (DO). A distance-based redundancy analysis was used to show that DO perturbations correlate with the abundance of Pseudomonadaceae and Rhodocyclaceae families, activities of peroxidases and cytochromes, and the degradation of OMPs. DO perturbation of 0.25 and 0.5 cycles/h led to most abundance of Pseudomonadaceae and Rhodocyclaceae families, showed higher activity of peroxidase and cytochrome, and gave largest removal of OMPs (removal of 92 ± 3% for sulfamethoxazole, 84 ± 3% for naproxen, 82 ± 3% for ibuprofen, 66 ± 2% for carbamazepine, 57 ± 15% for tylosin, and 88 ± 1% for atrazine).