Evaluating aquatic macrophytes for removing erythromycin from contaminated water: floating or submerged?

Water contamination by antibiotics is an emerging global problem, with impacts on both public health and the environment. Erythromycin has been encountered in bodies of water throughout the world, which demands the development of efficient remediation technologies. We investigated the physiological responses and phytoremediation capacity of four species of aquatic macrophytes, two floating (Salvinia molesta and Lemna minor) and two submerged (Myriophyllum aquaticum and Rotala rotundifolia). The plants were exposed to relevant environmental concentrations of erythromycin (0 and 1.7 mu g l(-1)) in artificially contaminated water for seven days. Physiological evaluations evidenced the ability of that antibiotic to promote oxidative events in those plants, such as the activation of antioxidant enzymes (ascorbate peroxidase and/or catalase). S. molesta exposed to erythromycin demonstrated accumulations of hydrogen peroxide and oxidative damage (lipid peroxidation) that was reflected in growth reductions. The erythromycin removal efficiency of floating plants varied from 9 to 12%, while submerged species varied from 31 to 44%. As such, submerged macrophyte species demonstrated the most efficient removal of erythromycin from contaminated waters, and are therefore more indicated for antibiotic phytoremediation projects. Novelty statement For the very first time, the capacities of floating and submerged plant species used for removing erythromycin from contaminated water were compared. Moreover, plant physiological responses were related to their phytoremediation capacity. Our results promise to have direct impacts on plant and environmental science as well as in toxicology since they will contribute to a better understanding of the effects of antibiotics in plants and indicate species for better performance of phytoremediation programs aiming to reclaim the antibiotic erythromycin.

Automated summary

Water contamination by antibiotics, especially erythromycin, is a global issue affecting public health and the environment. This study found that submerged macrophyte species are the most efficient at removing erythromycin from contaminated waters, making them more suitable for antibiotic phytoremediation projects. The research also highlighted the importance of understanding plant physiological responses in relation to phytoremediation capacity in order to improve remediation programs in the future.