[en] Human activities generate a multitude of polluting compounds that end up reaching the waters, causing negative effects on aquatic ecosystems, on the organisms that inhabit them and on our health. These can be classified as priority pollutants, such as atrazine (ATZ), a herbicide whose presence in the environment is regulated by law; and emerging pollutants, such as benzophenone-3 (BP-3), bisphenol A (BPA) and oxytetracycline (OTC), which correspond to a sunscreen, a chemical additive and an antibiotic, respectively, that do not have legislation governing its presence in the environment. In this paper we will study the response of the freshwater microalga, "Chlamydomonas reinhardtii", to these four compounds after 24 hours of exposure, in order to determine if there is a universal response by the latter to all the pollutants aforementioned. For this purpose, different parameters have been examined in relation to the possible cytotoxic effects caused, such as: cell growth, intrinsic cell properties, cell viability and vitality, cytoplasmic membrane potential, ROS production, lipid peroxidation and photosynthetic performance or efficiency. The results proved the toxicity of the four pollutants tested on the microalgae, triggering the same response for the parameters: growth rate, chlorophyll a fluorescence, cell vitality, membrane potential and photosynthetic performance. In addition, two groups of pollutants can be distinguished. On the one hand the BP-3 and the BPA, which affected all the parameters with the same response pattern, and on the other the OTC and the ATZ, which showed a similar response pattern and levels of viability and ROS without alterations with respect to controls.

[gl] As actividades humanas xeran multitude de compostos contaminantes que acaban chegando ás augas, provocando efectos negativos sobre os ecosistemas acuáticos, os organismos que habitan neles e sobre a nosa saúde. Estes pódense clasificar en prioritarios, como a atrazina (ATZ), un herbicida cuxa presenza no ambiente está regulada por lei; e emerxentes, como a benzofenona-3 (BP-3), o bisfenol A (BPA) e a oxitetraciclina (OTC), que se corresponden con un filtro solar, un aditivo químico e un antibiótico, respectivamente, os cales non dispoñen dunha lexislación que rexa a súa presenza no medio. No presente traballo estudarase a resposta da microalga de auga doce, "Chlamydomonas reinhardtii", a estes catro compostos tras 24 h de exposición, para poder determinar se existe unha resposta universal por parte desta a tódolos contaminantes citados. Para isto, examináronse distintos parámetros en relación aos posibles efectos citotóxicos provocados, tales como: crecemento celular, propiedades intrínsecas das células, viabilidade e vitalidade celular, potencial de membrana citoplasmática, produción de ROS, peroxidación lipídica e rendemento ou eficacia fotosintética. Os resultados evidenciaron a toxicidade dos catro contaminantes ensaiados sobre a microalga, desencadeando a mesma resposta para os parámetros: taxa de crecemento, fluorescencia da clorofila a, vitalidade celular, potencial de membrana e rendemento fotosintético. Ademais, pódense diferenciar dous grupos de contaminantes, por un lado o BP-3 e o BPA, que afectaron a tódolos parámetros cun mesmo patrón de resposta, e por outro a OTC e a ATZ, que mostraron un patrón de resposta moi similar entre elas e uns niveis de viabilidade e ROS sen alteracións respecto aos controis.