Tetracycline driven performance alters and microbial community shift in anaerobic digestion

The impact of different concentrations of tetracycline on the performance of anaerobic treatment was evaluated. It was found that at all of the tetracycline concentrations tested, no major sustained impact on methane production was observed. Instead, a significant increase in propionic acid was observed in the reactor subjected to 20 mg/L of tetracycline. Microbial community analyses suggest that an alternative methanogenesis pathway, specifically that of methanol-utilizing methanogens, may be important for ensuring the stability of methane production in the presence of high tetracycline concentrations. In addition, the accumulation of propionate was due to an increase in VFA-producing bacteria coupled with a reduction in propionate utilizers. An increase in the abundance of tetracycline resistance genes associated with RPP was observed after 30 days of exposure to high concentrations of tetracycline. These findings suggest that anaerobic treatment processes can robustly treat wastewaters with varying concentrations of antibiotics while also deriving value-added products and minimizing the dissemination of associated antibiotic resistance genes.