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Impacts of the combined exposure to seawater acidification and arsenic on the proteome of Crassostrea angulata and Crassostrea gigas

Publication . Moreira, Anthony; Figueira, Etelvina; Mestre, Nélia; Schrama, Denise; Soares, Amadeu M.V.M.; Freitas, Rosa; Bebianno, Maria

Proteomic analysis was performed to compare the effects of Arsenic (As), seawater acidification (Low pH) and the combination of both stressors (Low pH + As) on Crassostrea angulata and Crassostrea gigas juveniles in the context of global environmental change. This study aimed to elucidate if two closely related Crassostrea species respond similarly to these environmental stressors, considering both single and combined exposures, to infer if the simultaneous exposure to both stressors induced a differentiated response. Identification of the most important differentially expressed proteins between conditions revealed marked differences in the response of each species towards single and combined exposures, evidencing species-related differences towards each experimental condition. Moreover, protein alterations observed in the combined exposure (Low pH + As) were substantially different from those observed in single exposures. Identified proteins and their putative biological functions revealed an array of modes of action in each condition. Among the most important, those involved in cellular structure (Actin, Atlastin, Severin, Gelsolin, Coronin) and extracellular matrix modulation (Ependymin, Tight junction ZO-1, Neprilysin) were strongly regulated, although in different exposure conditions and species. Data also revealed differences regarding metabolic modulation capacity (ATP β, Enolase, Aconitate hydratase) and oxidative stress response (Aldehyde dehydrogenase, Lactoylglutathione, Retinal dehydrogenase) of each species, which also depended on single or combined exposures, illustrating a different response capacity of both oyster species to the presence of multiple stressors. Interestingly, alterations of piRNA abundance in C. angulata suggested genome reconfiguration in response to multiple stressors, likely an important mode of action related to adaptive evolution mechanisms previously unknown to oyster species, which requires further investigation. The present findings provide a deeper insight into the complexity of C. angulata and C. gigas responses to environmental stress at the proteome level, evidencing different capacities to endure abiotic changes, with relevance regarding the ecophysiological fitness of each species and competitive advantages in a changing environment.

2018Journal article

Open Access

Assessing cadmium-based quantum dots effect on the gonads of the marine mussel Mytilus galloprovincialis

Publication . Gonçalves, Joanna M.; Rocha, Thiago Lopes; Nélia Mestre, N. C. Mestre, N. Mestre; Fonseca, T. G.; Bebianno, M.

This study assesses the sex-specific effects induced by CdTe QDs, on the marine mussel Mytilus galloprovincialis in comparison to its dissolved counterpart. A 14 days exposure to CdTe QDs and dissolved Cd was conducted (10 mu g Cd L-1), analysing Cd accumulation, oxidative stress, biotransformation, metallothionein and oxidative damage in the gonads. Both Cd forms caused significant antioxidant alterations, whereby QDs were more pro-oxidant, leading to oxidative damage, being females more affected. Overall, biochemical impairments on gonads of M. galloprovincialis demonstrate that the reproductive toxicity induced by CdTe QDs in mussels are sex-dependent and mediated by oxidative stress and lipid peroxidation. It is crucial to acknowledge how gametes are affected by metal-based nanoparticles, such as Cd-based QDs. As well as understanding the potential changes they may undergo at the cellular level during gametogenesis, embryogenesis and larval development potentially leading to serious impacts on population sustainability and ecosystem health.

2020-04Journal article

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Anomalous levels in the southern Portuguese continental shelf sedimentary record: potential evidence of the 1755 CE Lisbon Tsunami

Publication . Kümmerer, Vincent; Veiga-Pires, C.; Drago, Teresa

At present, knowledge about tsunami event deposits in outer shelf environments with water depths > 60 m is limited, although understanding of the involved processes as tsunami induced erosion of seafloor sediments and induced backwash currents are critical for tsunami hazard assessment. Both, incoming tsunami waves and generated backwash currents can leave signatures in the offshore sedimentary record. Preservation of tsunami imprints seems more likely in offshore deposits as in onshore deposits, which are in contrary more regarded. Thus, a multidisciplinary approach was conducted to detect probable imprints left by the 1755 Lisbon tsunami event in 3 cores from the southern Portuguese continental shelf with water depths > 57 m. Age model results, based on 14C and 210Pb ages, confirm the ages of the sediment to the 1755 Lisbon tsunami event. Other extreme events such as storms can be excluded trough hydrodynamic considerations. Implementing new high-resolution methodologies as the multivariate analyses of sand composition and microtextural features on quartz grain surfaces yielded more evidence for a tsunamigenic origin of previous detected high energy event layers in the studied core sections in the context of ASTARTE project, although no remarkable terrigenous signal is present. The heterogenous and mixing character of the probable 1755 Lisbon offshore tsunami deposits coupled with hydrodynamic considerations suggest, that subunits related to different tsunami wave incursions and backwash phases re unlikely to be preserved in similar environments as the study area. Also, spatial depositional differences of tsunami sediments were encountered in the study area by differences in mean grain size, sand composition, and simulated horizontal surface velocities. The new applied methodologies contribute paleo-tsunami layer identification and facilitate new studies on offshore tsunami deposits. While the southern Portuguese shelf seems to be a very good study area, we suggest for near future works to collect multiple cores aligned in transects for a better understanding of tsunami sedimentation dynamics

2019-12-04Master thesis

Open Access

Ecotoxicological assessment of chemotherapeutic agents using toxicity tests with embryos of Mellita quinquiesperforata

Publication . Mello, Luiza Costa; Fonseca, Tainá; de Souza, Abessa Denis Moledode

The consumption of anticancer agents has increased in the recent decades, and these substances may be present in sewage. Consequently, they may reach the environment when sanitation infrastructure is ineffective. This study evaluated the toxicity of three anticancer agents-Tamoxifen (TAM), Cisplatin (CisPt), and Cyclophosphamide (CP)-on the development of embryos of the sand-dollar Mellita quinquiesperforata. Adult individuals were collected in sandy beaches, and gametes were obtained. Freshly-fertilized eggs were exposed to increasing sets of concentrations of each compound, and the effective concentrations needed to cause a 50% effect in the organisms (EC50) were calculated. The three compounds were toxic, and their EC50 values were 16.78 +/- 2.42 ng.L-1 (TAM), 27.20 +/- 38.26 ng.L-1 (CisPt), and 101.82 +/- 70.96 ng.L-1 (CP). There is no information on the environmental levels of these compounds in Brazil, but as they were already detected in ng.L-1 levels worldwide, it can be expected that these substances pose environmental risks to the marine biota.

2020-10Journal article

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Natural antioxidants in emulsions O/W

Publication . EL-GEUNDOUZ, Soukaina; Azza, S.; Dandlen, Susana Anahi; MAJDOUB, Nesrine; Lyoussi, Badiaa; Raposo, Sara; Gomes, Vera; Bankova, Vassya; Popova, Milena; Antunes, Maria Dulce; Miguel, Maria Graca

This study compared the capacity of propolis extract (PE) and thyme waste extract (TWE) to prevent the oxidation of oil in water (O/W) emulsion, as well as their impact on emulsion apparent viscosity (AV) in the presence of wheat germ and almond oils as lipid phase. For this, central composite design (CCD) and principal component analysis (PCA) were performed. Oxidation process was monitored by evaluating the formation of primary and secondary lipid oxidation products, at the same time the AV behavior was determined evaluating consistency index and flow behavior index. The results revealed that the increase of PE% and TWE% decreases TBARS (Thiobarbituric Acid Reactive Substances) and hydroperoxides formation. Viscosity increases with the rise of TWE% over (0.04%), whereas lower concentrations of PE% decreases it. Those results have been confirmed in the PCA analysis. TWE showed higher resistance to oxidation, although PE was more effective as antioxidant than TWE.

2020-05-06Journal article

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