Mario Diniz - Academia.edu (original) (raw)

Papers by Mario Diniz

Fermentation

Lactic acid bacteria (LAB) and Brettanomyces bruxellensis are the main contaminants of bioethanol... more Lactic acid bacteria (LAB) and Brettanomyces bruxellensis are the main contaminants of bioethanol fermentations. Those contaminations affect Saccharomyces cerevisiae performance and reduce ethanol yields and productivity, leading to important economic losses. Currently, chemical treatments such as acid washing and/or antibiotics are used to control those contaminants. However, these control measures carry environmental risks, and more environmentally friendly methods are required. Several S. cerevisiae wine strains were found to secrete antimicrobial peptides (AMPs) during alcoholic fermentation that are active against LAB and B. bruxellensis strains. Thus, in the present study, we investigated if the fuel-ethanol commercial starter S. cerevisiae Ethanol Red (ER) also secretes those AMPs and evaluated its biocontrol potential by performing alcoholic fermentations with mixed-cultures of ER and B. bruxellensis strains and growth assays of LAB in ER pre-fermented supernatants. Results ...

2019 IEEE 6th Portuguese Meeting on Bioengineering (ENBENG), 2019

Fast detection of biological contaminations is of great importance in several areas of human heal... more Fast detection of biological contaminations is of great importance in several areas of human health, such as, toxicology, environmental health and medicine. The need for developing sample retrieving methods in situ and techniques for fast and online detection of biological contamination is of crucial importance, not only for preventing infections but also to perform the most appropriate and effective medical treatment.In this work we report a method and an experimental protocol developed for the detection and analysis of VOCs emitted from bacteria by Ion Mobility Spectrometry coupled to Gas Chromatography (GC-IMS). As a biological model for study, the two Gram-Negative bacteria, Escherichia coli and Pseudomonas aeruginosa, were chosen. VOC profiles for these bacteria, individual and in the mixture, were obtained from the analysis of GC-IMS spectra. In addition, a study of the influence of the nutrition medium were performed.

International Journal of Environmental Research and Public Health, 2019

The exponential growth of nanotechnology has led to the production of large quantities of nanomat... more The exponential growth of nanotechnology has led to the production of large quantities of nanomaterials for numerous industrial, technological, agricultural, environmental, food and many other applications. However, this huge production has raised growing concerns about the adverse effects that the release of these nanomaterials may have on the environment and on living organisms. Regarding the effects of QDs on aquatic organisms, existing data is scarce and often contradictory. Thus, more information is needed to understand the mechanisms associated with the potential toxicity of these nanomaterials in the aquatic environment. The toxicity of QDs (ZnS and CdS) was evaluated in the freshwater fish Danio rerio. The fishes were exposed for seven days to different concentrations of QDs (10, 100 and 1000 µg/L) individually and combined. Oxidative stress enzymes (catalase, superoxide dismutase and glutathione S-transferase), lipid peroxidation, HSP70 and total ubiquitin were assessed. In...

ACS Omega, 2017

This work aims at assessing the influence of two different solvents, bidistilled water and toluen... more This work aims at assessing the influence of two different solvents, bidistilled water and toluene, on dispersions of carbon-based engineered nanomaterials, namely, fullerenes, and their self-assembly behavior. The obtained self-assembled carbon-based materials were characterized using UV−vis spectrophotometry and transmission electron microscopy techniques. The results obtained were unexpected when toluene was used for dispersing fullerene C 60 , with the formation of two different types of self-assembled structures: fullerene C 60 nanowhiskers (FNWs) and a type of quasispherical nanostructure. The FNWs ranged between 1 and 6 μm in length, whereas the quasispherical fullerene C 60 nanoaggregates ranged between 10 and 50 nm in diameter. Aggregates obtained in toluene showed a well-formed crystal structure. When using water, the obtained aggregates were amorphous and showed a no well-defined shape. Their sizes ranged between 20 and 40 nm for nanosized structures and between 0.4 and 4.8 μm for micron-sized self-aggregates.

Microscopy and Microanalysis, 2013

Engineered nanomaterials such as nanoparticles (NPs) are increasingly being used for commercial p... more Engineered nanomaterials such as nanoparticles (NPs) are increasingly being used for commercial purposes in products within medicine, electronics, sporting goods, tires, textiles and cosmetics. They comprise diverse types of materials from metals, polymers, ceramic to biomaterials and have been defined as particles with at least one dimension in the order up to 100 nm1. The higher toxicological potential of NPs is mostly due to their small size, wide surface, increase of their chemical reactivity and biological activity and the capacity to generate free radicals. NPs also can have the ability to penetrate trough the biological barriers and to move easily through the biological systems. Therefore, is mandatory to assess the toxicity of these nanomaterials, since their industrial production and uses will also result in releases to the environment with unclear consequences.The aim of the present work is to evaluate the toxicity of titanium dioxide (TiO2) NPs on gill gluthatione-S-trans...

Microscopy and Microanalysis, 2013

Nanoparticles (NPs), particles with at least one dimension less than 100 nm, are used in many ind... more Nanoparticles (NPs), particles with at least one dimension less than 100 nm, are used in many industrial applications and to produce new types of materials with unique physicochemical properties. The aquatic environment is commonly the ultimate recipient for NPs and there is uncertainty of exposure as understanding and data regarding the potential detrimental effects of NPs on aquatic biota are missing. In this study, titanium dioxide (TiO2) was chosen for its potential use in technology and diverse industrial applications. The objective of this work is to evaluate the toxicity of TiO2 NPs on total liver glutathione-S-transferase (GST), lipid peroxidation and tissue structure of the livers of two freshwater fish species (Carassius auratus and Danio rerio).Stock suspensions of TiO2 NPs, with an average size of 21 nm, were prepared using distilled water and then ultrasonicated (10 min, 35 KHz). The suspensions were added to 10L of tap water in exposure tanks, to obtain nominal concent...

Marine Ecology Progress Series, 2012

The effects of thermal conditions of coastal and estuarine nurseries, both in the present and in ... more The effects of thermal conditions of coastal and estuarine nurseries, both in the present and in the near future, on juvenile fish were compared. The response of the European seabass Dicentrarchus labrax was investigated through a long-term experiment in captivity, where 0-group juveniles were exposed to temperatures that reflect the average summer temperature that they encounter in coastal (18°C) and estuarine nurseries (24°C), and also the temperature that they endure inside estuaries during heat waves (28°C). The combined expression of 2 heat shock proteins (Hsc/Hsp70) in white muscle was assessed throughout a long-term experiment (30 d). Growth and condition were determined at the end of the experiment. Hsc/Hsp70 levels were constant throughout the first 15 d at 18°C, and then decreased steeply. At 24 and 28°C, Hsc/Hsp70 levels increased considerably after 15 d, particularly at 28°C, and decreased at the end of the experiment. Daily growth was 0.20 mm d −1 at 18°C, it increased to 0.34 mm d −1 at 24°C, and was lowest at 28°C, at 0.16 mm d −1. Condition, assessed by Fulton's K, was 0.95 at 18°C, 1.00 at 24°C and 0.83 at 28°C. The Hsc/Hsp70 increase at 24 and 28°C is an indication that molecular reparation processes were underway. The peak growth and condition values registered at 24°C suggest that estuarine average summer temperatures are more bene ficial for this species' juveniles than coastal temperatures. Acclimation was observed at 24°C, yet growth rates and condition values indicate that prolonged heat waves (28°C) may result in lower fitness.

Aquatic Toxicology, 2009

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit:

Ecotoxicology, 2009

Juvenile Solea senegalensis were exposed to fresh sediments from three stations of the Sado estua... more Juvenile Solea senegalensis were exposed to fresh sediments from three stations of the Sado estuary (Portugal) in 28-day laboratory assays. Sediments revealed distinct levels of total organic matter, fine fraction, redox potential, trace elements (arsenic, cadmium, chromium, copper, nickel, lead and zinc) and organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and a pesticide: dichloro diphenyl trichloroethane). Organisms were surveyed for contaminant bioaccumulation and induction of two hepatic biochemical biomarkers: metallothionein (MT) and cytochrome P450 (CYP1A), as potential indicators of exposure to metallic and organic contaminants, respectively. Using an integrative approach it was established that, although bioaccumulation is in general accordance with sediment contamination, lethality and biomarker responses are not linearly dependent of the cumulative concentrations of sediment contaminants but rather of their bioavailability and synergistic effects in organisms. It is concluded that metals and organic contaminants modulate both MT and CYP1A induction and it is suggested that reactive oxygen species may be the link between responses and effects of toxicity.

Science of The Total Environment

Environmental Pollution

Triclosan (TCS) is a synthetic microbial compound widely used in the formulation of various perso... more Triclosan (TCS) is a synthetic microbial compound widely used in the formulation of various personal care products. Its frequent detection in marine ecosystems, along with its physical and chemical properties, suggest that TCS can be highly persistent, being easily bioaccumulated by biota and, therefore, eliciting various toxicological responses. Yet, TCS's mechanisms of bioaccumulation and toxicity still deserve further research, particularly focusing on the interactive effects with climate change-related stressors (e.g. warming and acidification), as both TCS chemical behaviour and marine species metabolism/physiology can be strongly influenced by the surrounding abiotic conditions. Hence, the aim of this study was to assess TCS bioaccumulation and ecotoxicological effects (i.e. animal fitness indexes, antioxidant activity, protein chaperoning and degradation, neurotoxicity and endocrine disruption) in three tissues (i.e. brain, liver and muscle) of juvenile Diplodus sargus exposed to the interactive effects of TCS dietary exposure (15.9 μg kg dw), seawater warming (ΔTºC = +5 °C) and acidification (ΔpCO ∼ +1000 μatm, equivalent to ΔpH = -0.4 units). Muscle was the primary organ of TCS bioaccumulation, and climate change stressors, particularly warming, significantly reduced TCS bioaccumulation in all fish tissues. Furthermore, the negative ecotoxicological responses elicited by TCS were significantly altered by the co-exposure to acidification and/or warming, through either the enhancement (e.g. vitellogenin content) or counteraction/inhibition (e.g. heat shock proteins HSP70/HSC70 content) of molecular biomarker responses, with the combination of TCS plus acidification resulting in more severe alterations. Thus, the distinct patterns of TCS tissue bioaccumulation and ecotoxicological responses induced by the different scenarios emphasized the need to further understand the interactive effects between pollutants and abiotic conditions, as such knowledge enables a better estimation and mitigation of the toxicological impacts of climate change in marine ecosystems.

Environmental Research

Pharmaceuticals, such as the antidepressant venlafaxine (VFX), have been frequently detected in c... more Pharmaceuticals, such as the antidepressant venlafaxine (VFX), have been frequently detected in coastal waters and marine biota, and there is a growing body of evidence that these pollutants can be toxic to non-target marine biota, even at low concentrations. Alongside, climate change effects (e.g. warming and acidification) can also affect marine species' physiological fitness and, consequently, compromising their ability to cope with the presence of pollutants. Yet, information regarding interactive effects between pollutants and climate change-related stressors is still scarce. Within this context, the present study aims to assess the differential ecotoxicological responses (antioxidant activity, heat shock response, protein degradation, endocrine disruption and neurotoxicity) of juvenile fish (Argyrosomus regius) tissues (muscle, gills, liver and brain) exposed to VFX (via water or feed), as well as to the interactive effects of warming (ΔT °C = +5 °C) and acidification (ΔpCO ~ +1000 µatm, equivalent to ΔpH = -0.4 units), using an integrated multi-biomarker response (IBR) approach. Overall, results showed that VFX toxicity was strongly influenced by the uptake pathway, as well as by warming and acidification. More significant changes (e.g. increases surpassing 100% in lipid peroxidation, LPO, heat shock response protein content, HSP70/HSC70, and total ubiquitin content, Ub,) and higher IBR index values were observed when VFX exposure occurred via water (i.e. average IBR = 19, against 17 in VFX-feed treatment). The co-exposure to climate change-related stressors either enhanced (e.g. glutathione S-transferases activity (GST) in fish muscle was further increased by warming) or attenuated the changes elicited by VFX (e.g. vitellogenin, VTG, liver content increased with VFX feed exposure acting alone, but not when co-exposed with acidification). Yet, increased stress severity was observed when the three stressors acted simultaneously, particularly in fish exposed to VFX via water (i.e. average IBR = 21). Hence, the distinct fish tissues responses elicited by the different scenarios emphasized the relevance of performing multi-stressors ecotoxicological studies, as such approach enables a better estimation of the environmental hazards posed by pollutants in a changing ocean and, consequently, the development of strategies to mitigate them.

Marine environmental research, Jan 27, 2018

Extreme events associated with global warming, such as ocean heat waves, can have contrasting fit... more Extreme events associated with global warming, such as ocean heat waves, can have contrasting fitness consequences for different species, thereby modifying the structure and composition of marine communities. Here, we examined the effects of a laboratory simulated heat wave on the physiology and performance of two Indo-Pacific crustacean species: the shrimp Rhynchocinetes durbanensis and the hermit crab Calcinus laevimanus. We exposed the crustaceans to a control temperature or to a +5 °C temperature (25 °C vs 30 °C) for two consecutive weeks, and weekly analyzed protective proteins, antioxidant activity, and lipid peroxides in muscle and visceral mass. Fulton's K, total protein, %C, and C:N molar ratio of muscle tissue were also analyzed at the end of the experiment. Results showed that 1) the most responsive tissues were the muscle in the shrimp species and the visceral mass in the hermit crab species; 2) biomarker responses in both species occurred mostly after 7 days of expo...

The Science of the total environment, 2018

According to climate science, ocean warming is one of the current and future greatest threats to ... more According to climate science, ocean warming is one of the current and future greatest threats to coastal ecosystems. Projection scenarios for the end of this century show that tropical intertidal ecosystems are particularly at risk. In this study we optimized and tested a holistic method for bio-monitoring present and projected thermal pressure in such ecosystems, in order to assess organism vulnerability to ocean warming. Several species representative of different animal groups (fish, crustaceans and gastropods) were collected from the field and subjected to an experimental trial for 28 days, testing two temperatures: control (present seawater summer temperature) and elevated temperature (+3 °C, projected seawater temperature anomaly for 2100). Muscle samples were collected weekly to quantify several biomarkers of: i) macromolecular damage (protein unfolding and denaturation, and lipid peroxidation), ii) reactive oxygen species (ROS) scavengers (antioxidant enzymes), and iii) body...

Cell stress & chaperones, 2018

Atmospheric concentration of carbon dioxide (CO) is increasing at an unprecedented rate and subse... more Atmospheric concentration of carbon dioxide (CO) is increasing at an unprecedented rate and subsequently leading to ocean acidification. Concomitantly, ocean warming is intensifying, leading to serious and predictable biological impairments over marine biota. Reef-building corals have proven to be very vulnerable to climate change, but little is known about the resilience of non-reef-building species. In this study, we investigated the effects of ocean warming and acidification on the antioxidant enzyme activity (CAT-catalase, and GST-glutathione S-transferase), lipid peroxidation (using malondialdehyde, MDA-levels as a biomarker) and heat shock response (HSP70/HSC70 content) of the octocoral Veretillum cynomorium. After 60 days of acclimation, no mortalities were registered in all treatments. Moreover, CAT and GST activities, as well as MDA levels, did not change significantly under warming and/or acidification. Heat shock response was significantly enhanced under warming, but high...

Aquatic toxicology (Amsterdam, Netherlands), Jan 30, 2018

Pharmaceutical drugs, such as diclofenac (DCF), are frequently detected in the marine environment... more Pharmaceutical drugs, such as diclofenac (DCF), are frequently detected in the marine environment, and recent evidence has pointed out their toxicity to non-target marine biota. Concomitantly, altered environmental conditions associated with climate change (e.g. warming and acidification) can also affect the physiology of marine organisms. Yet, the underlying interactions between these environmental stressors (pharmaceutical exposure and climate change-related stressors) still require a deeper understanding. Comprehending the influence of abiotic variables on chemical contaminants' toxicological attributes provides a broader view of the ecological consequences of climate change. Hence, the aim of this study was to assess the ecotoxicological responses of juvenile seabass Dicenthrachus labrax under the co-exposure to DCF (from dietary sources, 500 ± 36 ng kg dw), warming (ΔTºC = +5 °C) and acidification (ΔpCO ∼1000 μatm, equivalent to ΔpH = -0.4 units), using an "Integrated ...

Chemosphere, Jan 2, 2018

The presence of antidepressants, such as venlafaxine (VFX), in marine ecosystems is increasing, t... more The presence of antidepressants, such as venlafaxine (VFX), in marine ecosystems is increasing, thus, potentially posing ecological and human health risks. The inherent mechanisms of VFX uptake and elimination still require further understanding, particularly accounting for the impact of climate change-related stressors, such as warming and acidification. Hence, the present work aimed to investigate, for the first time, the effects of increased seawater temperature (ΔT°C = +5 °C) and pCO levels (ΔpCO ∼1000 μatm, equivalent to ΔpH = -0.4 units) on the uptake and elimination of VFX in biological tissues (muscle, liver, brain) and plasma of juvenile meagre (Argyrosomus regius) exposed to VFX through two different exposure pathways (via water, i.e. [VFX ] ∼20 μg L, and via feed, i.e. [VFX] ∼160 μg kg dry weight, dw). Overall, results showed that VFX can be uptaken by fish through both water and diet. Fish liver exhibited the highest VFX concentration (126.7 ± 86.5 μg kg and 6786.4 ± 117...

Chemosphere, 2018

Rare earth elements (REEs) comprise elements from lanthanum to lutetium that together with yttriu... more Rare earth elements (REEs) comprise elements from lanthanum to lutetium that together with yttrium and scandium are emergent contaminants of critical importance for numerous groundbreaking environmental technologies. Transfer to aquatic ecosystems is expected to increase, however, little information is known about their potential impacts in marine biota. Considering the endangered conservation status of the European eel (Anguilla anguilla) and the vulnerability of early fish life stages to contaminants, we exposed glass eels, through water, to an environmentally relevant concentration (120 ng.L) of lanthanum (La) for 7 days (plus 7 days of depuration). The aim was to study the accumulation and elimination of La in eel's body and subsequent quantification of acetylcholinesterase (AchE), lipid peroxidation and antioxidant enzymatic machinery. Accumulation peaked after 72 h-exposure to La, decreasing afterwards, even in continuous exposure. Accumulation was higher in the viscera, f...

Cell stress & chaperones, Jan 27, 2018

Sharks have maintained a key role in marine food webs for 400 million years and across varying ph... more Sharks have maintained a key role in marine food webs for 400 million years and across varying physicochemical contexts, suggesting plasticity to environmental change. In this study, we investigated the biochemical effects of ocean acidification (OA) levels predicted for 2100 (pCO ~ 900 μatm) on newly hatched tropical whitespotted bamboo sharks (Chiloscyllium plagiosum). Specifically, we measured lipid, protein, and DNA damage levels, as well as changes in the activity of antioxidant enzymes and non-enzymatic ROS scavengers in juvenile sharks exposed to elevated CO for 50 days following hatching. Moreover, we also assessed the secondary oxidative stress response, i.e., heat shock response and ubiquitin levels. Newly hatched sharks appear to cope with OA-related stress through a range of tissue-specific biochemical strategies, specifically through the action of antioxidant enzymatic compounds. Our findings suggest that ROS-scavenging molecules, rather than complex enzymatic proteins,...

Fermentation

Lactic acid bacteria (LAB) and Brettanomyces bruxellensis are the main contaminants of bioethanol... more Lactic acid bacteria (LAB) and Brettanomyces bruxellensis are the main contaminants of bioethanol fermentations. Those contaminations affect Saccharomyces cerevisiae performance and reduce ethanol yields and productivity, leading to important economic losses. Currently, chemical treatments such as acid washing and/or antibiotics are used to control those contaminants. However, these control measures carry environmental risks, and more environmentally friendly methods are required. Several S. cerevisiae wine strains were found to secrete antimicrobial peptides (AMPs) during alcoholic fermentation that are active against LAB and B. bruxellensis strains. Thus, in the present study, we investigated if the fuel-ethanol commercial starter S. cerevisiae Ethanol Red (ER) also secretes those AMPs and evaluated its biocontrol potential by performing alcoholic fermentations with mixed-cultures of ER and B. bruxellensis strains and growth assays of LAB in ER pre-fermented supernatants. Results ...

2019 IEEE 6th Portuguese Meeting on Bioengineering (ENBENG), 2019

Fast detection of biological contaminations is of great importance in several areas of human heal... more Fast detection of biological contaminations is of great importance in several areas of human health, such as, toxicology, environmental health and medicine. The need for developing sample retrieving methods in situ and techniques for fast and online detection of biological contamination is of crucial importance, not only for preventing infections but also to perform the most appropriate and effective medical treatment.In this work we report a method and an experimental protocol developed for the detection and analysis of VOCs emitted from bacteria by Ion Mobility Spectrometry coupled to Gas Chromatography (GC-IMS). As a biological model for study, the two Gram-Negative bacteria, Escherichia coli and Pseudomonas aeruginosa, were chosen. VOC profiles for these bacteria, individual and in the mixture, were obtained from the analysis of GC-IMS spectra. In addition, a study of the influence of the nutrition medium were performed.

International Journal of Environmental Research and Public Health, 2019

The exponential growth of nanotechnology has led to the production of large quantities of nanomat... more The exponential growth of nanotechnology has led to the production of large quantities of nanomaterials for numerous industrial, technological, agricultural, environmental, food and many other applications. However, this huge production has raised growing concerns about the adverse effects that the release of these nanomaterials may have on the environment and on living organisms. Regarding the effects of QDs on aquatic organisms, existing data is scarce and often contradictory. Thus, more information is needed to understand the mechanisms associated with the potential toxicity of these nanomaterials in the aquatic environment. The toxicity of QDs (ZnS and CdS) was evaluated in the freshwater fish Danio rerio. The fishes were exposed for seven days to different concentrations of QDs (10, 100 and 1000 µg/L) individually and combined. Oxidative stress enzymes (catalase, superoxide dismutase and glutathione S-transferase), lipid peroxidation, HSP70 and total ubiquitin were assessed. In...

ACS Omega, 2017

This work aims at assessing the influence of two different solvents, bidistilled water and toluen... more This work aims at assessing the influence of two different solvents, bidistilled water and toluene, on dispersions of carbon-based engineered nanomaterials, namely, fullerenes, and their self-assembly behavior. The obtained self-assembled carbon-based materials were characterized using UV−vis spectrophotometry and transmission electron microscopy techniques. The results obtained were unexpected when toluene was used for dispersing fullerene C 60 , with the formation of two different types of self-assembled structures: fullerene C 60 nanowhiskers (FNWs) and a type of quasispherical nanostructure. The FNWs ranged between 1 and 6 μm in length, whereas the quasispherical fullerene C 60 nanoaggregates ranged between 10 and 50 nm in diameter. Aggregates obtained in toluene showed a well-formed crystal structure. When using water, the obtained aggregates were amorphous and showed a no well-defined shape. Their sizes ranged between 20 and 40 nm for nanosized structures and between 0.4 and 4.8 μm for micron-sized self-aggregates.

Microscopy and Microanalysis, 2013

Engineered nanomaterials such as nanoparticles (NPs) are increasingly being used for commercial p... more Engineered nanomaterials such as nanoparticles (NPs) are increasingly being used for commercial purposes in products within medicine, electronics, sporting goods, tires, textiles and cosmetics. They comprise diverse types of materials from metals, polymers, ceramic to biomaterials and have been defined as particles with at least one dimension in the order up to 100 nm1. The higher toxicological potential of NPs is mostly due to their small size, wide surface, increase of their chemical reactivity and biological activity and the capacity to generate free radicals. NPs also can have the ability to penetrate trough the biological barriers and to move easily through the biological systems. Therefore, is mandatory to assess the toxicity of these nanomaterials, since their industrial production and uses will also result in releases to the environment with unclear consequences.The aim of the present work is to evaluate the toxicity of titanium dioxide (TiO2) NPs on gill gluthatione-S-trans...

Microscopy and Microanalysis, 2013

Nanoparticles (NPs), particles with at least one dimension less than 100 nm, are used in many ind... more Nanoparticles (NPs), particles with at least one dimension less than 100 nm, are used in many industrial applications and to produce new types of materials with unique physicochemical properties. The aquatic environment is commonly the ultimate recipient for NPs and there is uncertainty of exposure as understanding and data regarding the potential detrimental effects of NPs on aquatic biota are missing. In this study, titanium dioxide (TiO2) was chosen for its potential use in technology and diverse industrial applications. The objective of this work is to evaluate the toxicity of TiO2 NPs on total liver glutathione-S-transferase (GST), lipid peroxidation and tissue structure of the livers of two freshwater fish species (Carassius auratus and Danio rerio).Stock suspensions of TiO2 NPs, with an average size of 21 nm, were prepared using distilled water and then ultrasonicated (10 min, 35 KHz). The suspensions were added to 10L of tap water in exposure tanks, to obtain nominal concent...

Marine Ecology Progress Series, 2012

The effects of thermal conditions of coastal and estuarine nurseries, both in the present and in ... more The effects of thermal conditions of coastal and estuarine nurseries, both in the present and in the near future, on juvenile fish were compared. The response of the European seabass Dicentrarchus labrax was investigated through a long-term experiment in captivity, where 0-group juveniles were exposed to temperatures that reflect the average summer temperature that they encounter in coastal (18°C) and estuarine nurseries (24°C), and also the temperature that they endure inside estuaries during heat waves (28°C). The combined expression of 2 heat shock proteins (Hsc/Hsp70) in white muscle was assessed throughout a long-term experiment (30 d). Growth and condition were determined at the end of the experiment. Hsc/Hsp70 levels were constant throughout the first 15 d at 18°C, and then decreased steeply. At 24 and 28°C, Hsc/Hsp70 levels increased considerably after 15 d, particularly at 28°C, and decreased at the end of the experiment. Daily growth was 0.20 mm d −1 at 18°C, it increased to 0.34 mm d −1 at 24°C, and was lowest at 28°C, at 0.16 mm d −1. Condition, assessed by Fulton's K, was 0.95 at 18°C, 1.00 at 24°C and 0.83 at 28°C. The Hsc/Hsp70 increase at 24 and 28°C is an indication that molecular reparation processes were underway. The peak growth and condition values registered at 24°C suggest that estuarine average summer temperatures are more bene ficial for this species' juveniles than coastal temperatures. Acclimation was observed at 24°C, yet growth rates and condition values indicate that prolonged heat waves (28°C) may result in lower fitness.

Aquatic Toxicology, 2009

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit:

Ecotoxicology, 2009

Juvenile Solea senegalensis were exposed to fresh sediments from three stations of the Sado estua... more Juvenile Solea senegalensis were exposed to fresh sediments from three stations of the Sado estuary (Portugal) in 28-day laboratory assays. Sediments revealed distinct levels of total organic matter, fine fraction, redox potential, trace elements (arsenic, cadmium, chromium, copper, nickel, lead and zinc) and organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and a pesticide: dichloro diphenyl trichloroethane). Organisms were surveyed for contaminant bioaccumulation and induction of two hepatic biochemical biomarkers: metallothionein (MT) and cytochrome P450 (CYP1A), as potential indicators of exposure to metallic and organic contaminants, respectively. Using an integrative approach it was established that, although bioaccumulation is in general accordance with sediment contamination, lethality and biomarker responses are not linearly dependent of the cumulative concentrations of sediment contaminants but rather of their bioavailability and synergistic effects in organisms. It is concluded that metals and organic contaminants modulate both MT and CYP1A induction and it is suggested that reactive oxygen species may be the link between responses and effects of toxicity.

Science of The Total Environment

Environmental Pollution

Triclosan (TCS) is a synthetic microbial compound widely used in the formulation of various perso... more Triclosan (TCS) is a synthetic microbial compound widely used in the formulation of various personal care products. Its frequent detection in marine ecosystems, along with its physical and chemical properties, suggest that TCS can be highly persistent, being easily bioaccumulated by biota and, therefore, eliciting various toxicological responses. Yet, TCS's mechanisms of bioaccumulation and toxicity still deserve further research, particularly focusing on the interactive effects with climate change-related stressors (e.g. warming and acidification), as both TCS chemical behaviour and marine species metabolism/physiology can be strongly influenced by the surrounding abiotic conditions. Hence, the aim of this study was to assess TCS bioaccumulation and ecotoxicological effects (i.e. animal fitness indexes, antioxidant activity, protein chaperoning and degradation, neurotoxicity and endocrine disruption) in three tissues (i.e. brain, liver and muscle) of juvenile Diplodus sargus exposed to the interactive effects of TCS dietary exposure (15.9 μg kg dw), seawater warming (ΔTºC = +5 °C) and acidification (ΔpCO ∼ +1000 μatm, equivalent to ΔpH = -0.4 units). Muscle was the primary organ of TCS bioaccumulation, and climate change stressors, particularly warming, significantly reduced TCS bioaccumulation in all fish tissues. Furthermore, the negative ecotoxicological responses elicited by TCS were significantly altered by the co-exposure to acidification and/or warming, through either the enhancement (e.g. vitellogenin content) or counteraction/inhibition (e.g. heat shock proteins HSP70/HSC70 content) of molecular biomarker responses, with the combination of TCS plus acidification resulting in more severe alterations. Thus, the distinct patterns of TCS tissue bioaccumulation and ecotoxicological responses induced by the different scenarios emphasized the need to further understand the interactive effects between pollutants and abiotic conditions, as such knowledge enables a better estimation and mitigation of the toxicological impacts of climate change in marine ecosystems.

Environmental Research

Pharmaceuticals, such as the antidepressant venlafaxine (VFX), have been frequently detected in c... more Pharmaceuticals, such as the antidepressant venlafaxine (VFX), have been frequently detected in coastal waters and marine biota, and there is a growing body of evidence that these pollutants can be toxic to non-target marine biota, even at low concentrations. Alongside, climate change effects (e.g. warming and acidification) can also affect marine species' physiological fitness and, consequently, compromising their ability to cope with the presence of pollutants. Yet, information regarding interactive effects between pollutants and climate change-related stressors is still scarce. Within this context, the present study aims to assess the differential ecotoxicological responses (antioxidant activity, heat shock response, protein degradation, endocrine disruption and neurotoxicity) of juvenile fish (Argyrosomus regius) tissues (muscle, gills, liver and brain) exposed to VFX (via water or feed), as well as to the interactive effects of warming (ΔT °C = +5 °C) and acidification (ΔpCO ~ +1000 µatm, equivalent to ΔpH = -0.4 units), using an integrated multi-biomarker response (IBR) approach. Overall, results showed that VFX toxicity was strongly influenced by the uptake pathway, as well as by warming and acidification. More significant changes (e.g. increases surpassing 100% in lipid peroxidation, LPO, heat shock response protein content, HSP70/HSC70, and total ubiquitin content, Ub,) and higher IBR index values were observed when VFX exposure occurred via water (i.e. average IBR = 19, against 17 in VFX-feed treatment). The co-exposure to climate change-related stressors either enhanced (e.g. glutathione S-transferases activity (GST) in fish muscle was further increased by warming) or attenuated the changes elicited by VFX (e.g. vitellogenin, VTG, liver content increased with VFX feed exposure acting alone, but not when co-exposed with acidification). Yet, increased stress severity was observed when the three stressors acted simultaneously, particularly in fish exposed to VFX via water (i.e. average IBR = 21). Hence, the distinct fish tissues responses elicited by the different scenarios emphasized the relevance of performing multi-stressors ecotoxicological studies, as such approach enables a better estimation of the environmental hazards posed by pollutants in a changing ocean and, consequently, the development of strategies to mitigate them.

Marine environmental research, Jan 27, 2018

Extreme events associated with global warming, such as ocean heat waves, can have contrasting fit... more Extreme events associated with global warming, such as ocean heat waves, can have contrasting fitness consequences for different species, thereby modifying the structure and composition of marine communities. Here, we examined the effects of a laboratory simulated heat wave on the physiology and performance of two Indo-Pacific crustacean species: the shrimp Rhynchocinetes durbanensis and the hermit crab Calcinus laevimanus. We exposed the crustaceans to a control temperature or to a +5 °C temperature (25 °C vs 30 °C) for two consecutive weeks, and weekly analyzed protective proteins, antioxidant activity, and lipid peroxides in muscle and visceral mass. Fulton's K, total protein, %C, and C:N molar ratio of muscle tissue were also analyzed at the end of the experiment. Results showed that 1) the most responsive tissues were the muscle in the shrimp species and the visceral mass in the hermit crab species; 2) biomarker responses in both species occurred mostly after 7 days of expo...

The Science of the total environment, 2018

According to climate science, ocean warming is one of the current and future greatest threats to ... more According to climate science, ocean warming is one of the current and future greatest threats to coastal ecosystems. Projection scenarios for the end of this century show that tropical intertidal ecosystems are particularly at risk. In this study we optimized and tested a holistic method for bio-monitoring present and projected thermal pressure in such ecosystems, in order to assess organism vulnerability to ocean warming. Several species representative of different animal groups (fish, crustaceans and gastropods) were collected from the field and subjected to an experimental trial for 28 days, testing two temperatures: control (present seawater summer temperature) and elevated temperature (+3 °C, projected seawater temperature anomaly for 2100). Muscle samples were collected weekly to quantify several biomarkers of: i) macromolecular damage (protein unfolding and denaturation, and lipid peroxidation), ii) reactive oxygen species (ROS) scavengers (antioxidant enzymes), and iii) body...

Cell stress & chaperones, 2018

Atmospheric concentration of carbon dioxide (CO) is increasing at an unprecedented rate and subse... more Atmospheric concentration of carbon dioxide (CO) is increasing at an unprecedented rate and subsequently leading to ocean acidification. Concomitantly, ocean warming is intensifying, leading to serious and predictable biological impairments over marine biota. Reef-building corals have proven to be very vulnerable to climate change, but little is known about the resilience of non-reef-building species. In this study, we investigated the effects of ocean warming and acidification on the antioxidant enzyme activity (CAT-catalase, and GST-glutathione S-transferase), lipid peroxidation (using malondialdehyde, MDA-levels as a biomarker) and heat shock response (HSP70/HSC70 content) of the octocoral Veretillum cynomorium. After 60 days of acclimation, no mortalities were registered in all treatments. Moreover, CAT and GST activities, as well as MDA levels, did not change significantly under warming and/or acidification. Heat shock response was significantly enhanced under warming, but high...

Aquatic toxicology (Amsterdam, Netherlands), Jan 30, 2018

Pharmaceutical drugs, such as diclofenac (DCF), are frequently detected in the marine environment... more Pharmaceutical drugs, such as diclofenac (DCF), are frequently detected in the marine environment, and recent evidence has pointed out their toxicity to non-target marine biota. Concomitantly, altered environmental conditions associated with climate change (e.g. warming and acidification) can also affect the physiology of marine organisms. Yet, the underlying interactions between these environmental stressors (pharmaceutical exposure and climate change-related stressors) still require a deeper understanding. Comprehending the influence of abiotic variables on chemical contaminants' toxicological attributes provides a broader view of the ecological consequences of climate change. Hence, the aim of this study was to assess the ecotoxicological responses of juvenile seabass Dicenthrachus labrax under the co-exposure to DCF (from dietary sources, 500 ± 36 ng kg dw), warming (ΔTºC = +5 °C) and acidification (ΔpCO ∼1000 μatm, equivalent to ΔpH = -0.4 units), using an "Integrated ...

Chemosphere, Jan 2, 2018

The presence of antidepressants, such as venlafaxine (VFX), in marine ecosystems is increasing, t... more The presence of antidepressants, such as venlafaxine (VFX), in marine ecosystems is increasing, thus, potentially posing ecological and human health risks. The inherent mechanisms of VFX uptake and elimination still require further understanding, particularly accounting for the impact of climate change-related stressors, such as warming and acidification. Hence, the present work aimed to investigate, for the first time, the effects of increased seawater temperature (ΔT°C = +5 °C) and pCO levels (ΔpCO ∼1000 μatm, equivalent to ΔpH = -0.4 units) on the uptake and elimination of VFX in biological tissues (muscle, liver, brain) and plasma of juvenile meagre (Argyrosomus regius) exposed to VFX through two different exposure pathways (via water, i.e. [VFX ] ∼20 μg L, and via feed, i.e. [VFX] ∼160 μg kg dry weight, dw). Overall, results showed that VFX can be uptaken by fish through both water and diet. Fish liver exhibited the highest VFX concentration (126.7 ± 86.5 μg kg and 6786.4 ± 117...

Chemosphere, 2018

Rare earth elements (REEs) comprise elements from lanthanum to lutetium that together with yttriu... more Rare earth elements (REEs) comprise elements from lanthanum to lutetium that together with yttrium and scandium are emergent contaminants of critical importance for numerous groundbreaking environmental technologies. Transfer to aquatic ecosystems is expected to increase, however, little information is known about their potential impacts in marine biota. Considering the endangered conservation status of the European eel (Anguilla anguilla) and the vulnerability of early fish life stages to contaminants, we exposed glass eels, through water, to an environmentally relevant concentration (120 ng.L) of lanthanum (La) for 7 days (plus 7 days of depuration). The aim was to study the accumulation and elimination of La in eel's body and subsequent quantification of acetylcholinesterase (AchE), lipid peroxidation and antioxidant enzymatic machinery. Accumulation peaked after 72 h-exposure to La, decreasing afterwards, even in continuous exposure. Accumulation was higher in the viscera, f...

Cell stress & chaperones, Jan 27, 2018

Sharks have maintained a key role in marine food webs for 400 million years and across varying ph... more Sharks have maintained a key role in marine food webs for 400 million years and across varying physicochemical contexts, suggesting plasticity to environmental change. In this study, we investigated the biochemical effects of ocean acidification (OA) levels predicted for 2100 (pCO ~ 900 μatm) on newly hatched tropical whitespotted bamboo sharks (Chiloscyllium plagiosum). Specifically, we measured lipid, protein, and DNA damage levels, as well as changes in the activity of antioxidant enzymes and non-enzymatic ROS scavengers in juvenile sharks exposed to elevated CO for 50 days following hatching. Moreover, we also assessed the secondary oxidative stress response, i.e., heat shock response and ubiquitin levels. Newly hatched sharks appear to cope with OA-related stress through a range of tissue-specific biochemical strategies, specifically through the action of antioxidant enzymatic compounds. Our findings suggest that ROS-scavenging molecules, rather than complex enzymatic proteins,...