Estudio metalo-metabolómico de bioindicadores de áreas costeras y estuarinas del suroeste de la Península Ibérica

Resumen

Aquatic invertebrates are very good biomarkers that are particularly useful for assessing the quality of aquatic ecosystems, these bioindicator species have to meet a number of features such as having a wide distribution and abundance, as well as to present a relationship between pollutant content in their tissues and its concentration in the environment. On the other hand, they have to be suitable for laboratory studies. These organisms have been used in numerous studies related to bioaccumulation of pollutants to determine changes in their metabolic pathways caused by xenobiotics exposure. In connection to this our study considers the toxicological mode of action of metals and drugs on theses bioindicators, which has been the more important topic of this doctoral Thesis. Environmental pollution in aquatic ecosystems due to human activities has led to the existence of a special interest in the study of biomarkers. However, the conventional analysis of biomarkers although provide information about the impact of pollution on the health of ecosystems, they do not allow to deep insight into the toxicological mechanisms that are involved in the pollutant action. Therefore, the omics are now the new tool to assess the overall biological response to pollution, in particular the presence and modifications suffered by metal-biomolecules and metabolites used as biomarkers of environmental stress. The new analytical coupling based on HPLC-ICP-MS to characterized metal-containing biomolecules (metallomics) together to rapid an effective extraction technique of biological fluids and new high resolution mass spectrometric techniques for species identification are opening new possibilities in environmental studies. Besides the combination of omics, such as metallomics and metabolomics in the present study are opening a new frontier in biomonitoring the action of pollutants in the ecosystems. This study focuses on the evaluation and monitoring of environmental pollution in the southwest of the Iberian Peninsula using as biomarkers three invertebrates, the molluscs Scrobicularia plana and Ruditapes philippinarum molluscs and the crustacean Procambarus clarkii, studying the presence and modifications suffered by these biomarkers under environmental stress (considering the changes in metal-biomolecules and metabolites). In addition, controlled exposure experiments involving severl drugs have been performed and changes in metabolic pathways considered. The study was centered on the environmental pollution in the southwest of the Iberian Peninsula (Algarve-Cádiz-Donana National Park and surroundings) by analyzing metal-biomolecules related to environmental stress. For this purpose Scrobicularia plana and Procambarus clarkii collected in the different areas of study were studied. A metallomics workflow based on the use of size exclusion chromatography with elemental detection by ICP-MS was developed, which has been applied to different organs of the bioindicators in order to identify potential metal-containing biomolecules changes as consequence of environmental pollution. Furthermore, in the case of Procambarus clarkii, other biomarkers related to metal contamination (metallothioneins and lipid peroxidation) have been considered and an analytical approach for arsenic speciation using ion chromatography-ICP -MS was used to compare polluted and unpolluted areas. Furthermore, a metabolomic approach based on fast liquid-liquid extraction of metabolites followed by metabolites detection by direct infusion tandem mass spectrometry (ESI-QqTOF) has been performed in order to establish the metabolites related to the response of different organs from the crab Procambarus clarkii to environmental stress. In addition exposure experiments of bivalve Ruditapes phillipinarum to different drugs (ibuprofen, diclofenac and carbamazepine) with the purpose of identify possible changes in metabolic pathways under the action of these emerging contaminants. The use of crustaceans and bivalve molluscs, with a simpler metabolism allows easier interpretation of contaminant that can be extrapolated later to more complex organisms.