Occurrence of veterinary drugs and resistance genes during anaerobic digestion of poultry and cattle manures

• Published in: The Science of the total environment Vol. 822; p. 153477
• Main Authors: Zahedi, Soraya, Gros, Meritxell, Casabella, Oriol, Petrovic, Mira, Balcazar, Jose Luis, Pijuan, Maite
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.05.2022
• Subjects: Agro-industrial wastes; Anaerobic treatment; Anaerobiosis; Animals; Anti-Bacterial Agents - pharmacology; Antibiotic resistance; Biochemical methane potential tests; Biogas; Cattle; Contaminants of emerging concern; Drug Resistance, Microbial - genetics; Manure - analysis; Poultry; Veterinary Drugs; Biogas; Agro-industrial wastes; Contaminants of emerging concern; Biochemical methane potential tests; Antibiotic resistance; Anaerobic treatment
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2022.153477

In the present paper, the mesophilic (35 °C) and thermophilic (55 °C) biomethanization of poultry and cattle manures were investigated using biochemical methane potential (BMP) tests. Specific methane production (SMP), 24 pharmaceutical compounds (PhACs), and five antibiotic resistance genes (ARGs) (blaKPC, ermB, qnrS, sul1 and tetW) together with the microbial community were analyzed. Mesophilic BMP tests resulted in the highest SMP when poultry manure was used (285.5 mL CH4/g VSS with poultry vs 239.6 mL CH4/g VSS with cattle manure) while thermophilic temperatures led to the highest SMP with cattle manure (231.2 mL CH4/g VSS with poultry vs 238.0 mL CH4/g VSS with cattle manure). Higher removals of veterinary pharmaceuticals were detected at 55 °C with both manures indicating that thermophilic digestion is better suited for the removal of these compounds. Tylosin, tilmicosin, chlortetracycline, and sulfamethoxazole presented removals higher than 50%, being the first two completely removed under mesophilic and thermophilic conditions. When comparing the relative abundance of ARGs at the end of each treatment, the most significant removal was found for qnrS which was not detected after the anaerobic treatment. The remaining ARGs did not suffer significant changes. Finally, microbial composition analysis showed that temperature affected the final microbial population more than the microorganisms present in the substrate or inoculum. [Display omitted] •Mesophilic temperature gave higher specific methane production with poultry manure.•SMP was similar at mesophilic and thermophilic temperatures for cattle manure.•Thermophilic conditions resulted in higher removals of veterinary pharmaceuticals.•Only one ARG (qnrS) was completely removed during anaerobic digestion.