Accelerated degradation of antiviral ribavirin by microalgae fuel cell (MFC), electricity generation and key metabolic process

Abstrct Microalgae are capable of removing various organic pollutants through their inherent processes of growth, reproduction and biological metabolism. In present study, a microalgae-based fuel cell was constructed using Chlorella sp. SI-50, significantly improving the removal efficiency of the antiviral ribavirin (RBV) from wastewater. Compared with conventional microalgal systems, which typically achieve only 70% removal of RBV within 18 days, the present system achieved complete elimination (100%) of 5 mg/L RBV by day 6. Furthermore, the microalgal antioxidant enzyme system exhibited outstanding antioxidant activity, which was attributed to oxidative stress from microcurrent and electron transfer. Transcriptomic analysis screened phosphotransferase and nucleotide transferase as key enzymes involved in RBV biodegradation. These enzymes participate in purine/pyrimidine metabolism and xenobiotic detoxification, potentially catalyzing RBV oxidation and conjugation. This work highlights that microalgal electrochemical systems efficiently enhance the remediation of antiviral contaminants and reveal core molecular mechanisms underlying RBV metabolism, providing a promising eco-friendly strategy for the treatment of pharmaceutical wastewater.