Global antibiotic consumption is increasing dramatically.Antibiotic release into the environment, primarily through wastewater discharge, has serious impacts for human and animal health and microbial ecosystems.To address this issue, white-rot fungi present a promising solution, as they possess oxidative enzymes that can degrade these pollutants.Here we investigated the effectiveness of read more the white-rot fungus Bjerkandera adusta TM11 for removing three persistent fluoroquinolone antibiotics, i.e.
levofloxacin, ciprofloxacin, and enrofloxacin, in real wastewater.The three antibiotics were added to the wastewater separately at a concentration of 30 mg/L and together in a cocktail at 10 mg/L, then incubated for 9 days.LC-MS/MS lochby venture pouch analysis and anti-microbial assay (against Escherichia coli) demonstrated complete removal of levofloxacin by day 7.However, ciprofloxacin and enrofloxacin biotransformed into degradation products that still had antimicrobial activity, with degradation efficiencies reaching 82 % and 99 %, respectively, by day 7.Proteomic analysis identified 21 fungal heme peroxidases.
Versatile peroxidase was the most strongly-produced enzyme potentially involved in antibiotic biotransformation.Degradation products were characterized by LC-MS/MS analysis, and a degradation pathway was proposed based on these findings.