Morpho-physiological responses by Chlamydomonas reinhardtii to different concentrations of ibuprofen

Pollution of aquatic bodies by pharmaceutical compounds is an emerging environmental problem because these drugs are extensively used in animal and human medicine. Ibuprofen, 2-[4-(2-methylpropyl)phenyl] propanoic acid, is the non-steroidal anti-inflammatory drug mainly present both in wastewater and in rivers and lakes in Europe. Despite this environmental emergency is giving rise a great interest in the scientific community, literature about the effects of ibuprofen on microalgae is scarce. A previous work on the freshwater microalga Scenedesmus rubescens had shown some morpho-physiological effects caused by treatment with 62.5, 250 and 1000 mu g L-1 ibuprofen. In this paper, we presented the results of treatment with ibuprofen at the same concentrations, ranging from environmental levels up to higher values, on Chlamydomonas reinhardtii (P.J.L. Dangeard). Ibuprofen effects on the alga were assayed through analyses of growth curve. Moreover, analyses of cell morphology, ultrastructure, and photosynthetic pigments were performed. The first effect of drug was the stimulation of the microalga growth. In addition, following exposure to ibuprofen, cells exhibited morphological and ultrastructural alterations, the latter ones consisting of starch granules and both in vacuolar and cytoplasmatic inclusions. On the contrary, chlorophyll and carotenoids amounts, were not affected by drug treatment.