Toxic effects of erythromycin to freshwater and marine microalgae

[Excerpt] Erythromycin (ERT) is a macrolide antibiotic frequently used in human and animal health care to combat bacterial infections and in aquaculture and livestock as growth promoter. A high part of the administered ERT is not adsorbed being eliminated to wastewater treatment plants where is not effectively removed/degraded [1]. Therefore, ERT has been found in aquatic systems (at ng L-1 to µg L-1) [2]. However, the knowledge of ERT impact to non-target organisms is limited. Microalgae, as primary producers, are one of the first organisms to be in contact with aquatics contaminants. Thus, it is of emerging concern to study the impact of ERT in freshwater and marine microalgae. In this study, it was evaluated the impact of ERT on the growth of the freshwater alga Pseudokirchneriella subcapitata (during 72 h) and of the marine Dunaliella tertiolecta (during 96 h). EC10 of 5 and 1880 µg L-1 and EC50 of 38 and 5745 µg L-1 were obtained for P. subcapitata and D. tertiolecta, respectively. So, the freshwater alga P. subcapitata presented a higher sensitivity (ppb level) to ERT than marine one (ppm level). [...]