Browsing by Author "Lage, Sandra"
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- Chemical composition and species identification of microalgal biomass grown at pilot-scale with municipal wastewater and CO2 from flue gasesPublication . Lage, Sandra; Gentili, Francesco G.The production potential of a locally isolated Chlorella vulgaris strain and a local green-algae consortium, used in municipal wastewater treatment combined with CO2 sequestration from flue gases, was evaluated for the first time by comparing the elemental and biochemical composition and heating value of the biomass produced. The microalgae were grown in outdoor pilot-scale ponds under subarctic summer conditions. The impact of culti-vation in a greenhouse climate was also tested for the green-algae consortium; additionally, the variation in species composition over time in the three ponds was investigated. Our results showed that the biomass produced in the consortium/outdoor pond had the greatest potential for bioenergy production because both its carbohy-drates and lipids contents were significantly higher than the biomasses from the consortium/greenhouse and C. vulgaris/outdoor ponds. Although greenhouse conditions significantly increased the consortium biomass's monounsaturated fatty acid content, which is ideal for biodiesel production, an undesirable increase in ash and chemical elements, as well as a reduction in heating value, were also observed. Thus, the placement of the pond inside a greenhouse did not improve the production potential of the green-algae consortium biomass in the current study infrastructure and climate conditions.
- Circannual prevalence of tetrodotoxins in trumpet shells: sea stars as a possible source of contamination and Implications for food safetyPublication . Pais, Maria; Carvalho, Flávia; Frade, Magda; Reis Costa, Pedro; Silva, José Paulo da; Marçalo, Ana; Canario, Adelino; Lage, SandraTetrodotoxin (TTX) is a potent neurotoxin, first identified in fish from the Tetraodontidae family but also detected in marine invertebrates. A Human poisoning episode after consumption of trumpet shell Charonia lampas, likely caught off the Portuguese mainland southern coast - Algarve, together with the increasing reports of TTX in European waters, led the European Food Safety Authority (EFSA) to recommend maximum safe limits for Human consumption of shellfish meat. However, data on temporal and species incidence of TTX are lacking. In the present study, TTX and its analogues were analysed by liquid chromatography-high resolution mass spectrometry (LC-HRMS) in trumpet shells and in one of their potential prey sources of TTX, the sea star Astropecten aranciacus. The estimated toxicity, based on a Toxicity Equivalency Factors approach, of non-edible trumpet shell tissues consistently surpassed EFSA limits (44 mu g TTX equivalent (eq.) kg(-1)) over the studied year. A correlation between TTX concentration and bottom seawater temperature suggests a possible role of this parameter in TTX uptake. TTX levels in edible trumpet shell tissues and all but one sea star individual were below quantification limits. However, several TTX analogues were quantified in the sea stars, resulting in estimated toxicities (monthly averages) ranging from 7 to 64 mu g TTX eq kg(-1) in the digestive glands and from 0.3 to 27 mu g TTX eq. kg(-1) in the stomachs. Therefore, the sea star is a possible TTX source for trumpet shells. Despite the absence of TTX in common edible parts of trumpet shells, whole-shell sales in markets pose a consumer risk, highlighting the need for TTX monitoring and public awareness programs to prevent poisoning.
- Effect of temperature on growth and yessotoxin production of protoceratium reticulatum and lingulodinium polyedra (Dinophyceae) isolates from the Portuguese coast (NE Atlantic)Publication . Barbosa, Miguel; Reis Costa, Pedro; David, Helena; Lage, Sandra; Amorim, AnaThe dinoflagellates Protoceratium reticulatum and Lingulodinium polyedra are potential yessotoxin (YTX) producers, which have been associated with blooms responsible for economic, social, and ecological impacts around the world. They occur in Iberian waters, but in this region, little is known of their ecophysiology and toxin profiles. This study investigated the growth and toxin production of two strains of each species, from the Portuguese coast, at 15 degrees C, 19 degrees C, and 23 degrees C. Growth curves showed higher growth rates at 19 degrees C, for both species. YTX and three analogs (homo YTX; 45-OH YTX; 45-OH homo YTX) were investigated by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS), and the presence of other analogs was investigated by Liquid Chromatography-High-Resolution Mass Spectrometry (LC-HRMS). No evidence of toxin production was found in L. polyedra. By contrast, YTX and 45,55-diOH-YTX were detected in both strains of P. reticulatum. These results confirm P. reticulatum as a source of yessotoxins along the Portuguese coast and add to the observed high intraspecific variability on YTX production of both species, at a global scale.
- Grazer‐induced bioluminescence and toxicity in marine dinoflagellatesPublication . Gonzalo‐Valmala, Paula; Pourdanandeh, Milad; Lage, Sandra; Selander, ErikMarine copepods are the most abundant multicellular zooplankton in the global oceans. They imprint their surrounding waters with a unique bouquet of chemical compounds, including polar lipids such as copepodamides. Prey organisms can detect copepodamides and respond by inducing defensive traits including bioluminescence, toxin production, changes in colony size, and structural modifications. This mechanism has been suggested to contribute to harmful algal bloom formation, but to date only a limited number of species and strains have been experimentally exposed to copepodamides. Here, we quantify bioluminescence and toxin content in response to increasing concentrations of copepodamides in three harmful algal bloom-forming species of marine dinoflagellates: Alexandrium catenella, Protoceratium reticulatum, and Gymnodinium catenatum. All three species up-regulated their defensive traits in response to copepodamide exposure, including the first example of copepodamide-induced GC-toxin production. Neither bioluminescence nor toxin production was associated with measurable costs in terms of reduced growth rates. The results support the role of copepodamides as general alarm cues in marine phytoplankton. Moreover, the expression of simultaneous defensive traits may confound studies addressing the costs and benefits of these co-varying traits.
- Gymnodinium catenatum paralytic Shellfish toxin production and photobiological responses under marine heat wavesPublication . Lopes, Vanessa M.; Court, Mélanie; Seco, Martim Costa; Borges, Francisco O.; Vicente, Bernardo; Lage, Sandra; Braga, Ana Catarina; Duarte, Bernardo; Santos, Catarina Frazão; Amorim, Ana; Reis Costa, Pedro; Rosa, RuiMarine heatwaves (MHWs) have doubled in frequency since the 1980s and are projected to be exacerbated during this century. MHWs have been shown to trigger harmful algal blooms (HABs), with severe consequences to marine life and human populations. Within this context, this study aims to understand, for the first time, how MHWs impact key biological and toxicological parameters of the paralytic shellfish toxin (PST) producer Gymnodinium catenatum, a dinoflagellate inhabiting temperate and tropical coastal waters. Two MHW were simulated—category I (i.e., peak: 19.9 ◦C) and category IV (i.e., peak: 24.1 ◦C)—relative to the estimated baseline in the western coast of Portugal (18.5 ◦C). No significant changes in abundance, size, and photosynthetic efficiency were observed among treatments. On the other hand, chain-formation was significantly reduced under category IV MHW, as was PSP toxicity and production of some PST compounds. Overall, this suggests that G. catenatum may have a high tolerance to MHWs. Nevertheless, some sublethal effects may have occurred since chain-formation was affected, suggesting that these growth conditions may be sub-optimal for this population. Our study suggests that the increase in frequency, intensity, and duration of MHWs may lead to reduced severity of G. catenatum blooms.
- LC-HRMS profiling of paralytic shellfish toxins in Mytilus galloprovincialis after a Gymnodinium catenatum bloomPublication . Lage, Sandra; Reis Costa, Pedro; Canario, Adelino; Da Silva, José PauloSaxitoxin and its more than 50 analogues are a group of naturally occurring neurotoxins collectively designated as paralytic shellfish toxins (PSTs). PSTs are toxic to humans and maximum legal limits in seafood have been implemented by regulatory authorities worldwide. In the European Union, monitoring of PSTs is performed using the AOAC Official Method 2005.06, based on liquid chromatography coupled with fluorescence detection (LC- FLD). However, this method has been suggested to not effectively detect the emerging C-11 hydroxyl (M-toxins) and benzoate (GC-toxins) analogues, with these analogues currently not being surveyed in monitoring programs. In this study, a liquid chromatography-high resolution mass spectrometry (LC-HRMS) method was used to search for these emerging PSTs in mussels, Mytilus galloprovincialis, contaminated following an intense Gymnodinium catenatum bloom in the Tagus estuary (Lisbon, Portugal). Five M-toxins (M1, M2, M6, dcM6, and dcM10), but no GC-toxins, were detected in the mussels’ whole-soft body tissue. Moreover, the classical PSTs (C1 to C4, GTX 4 to GTX6, dcGTX1 to dcGTX4, dcSTX, dcNEO, and STX) were also found and comprised the largest fraction of the PSTs’ profile. The presence of unregulated PSTs in edible mussel samples suggests potential seafood safety risks and urges further research to determine the frequency of these analogues in seafood and their contribution to toxicity
- Metabolomic and taxonomic characterization of Haloleptolyngbya lusitanica sp. nov . (Cyanobacteria, Synechococcales)Publication . Cordeiro, Rita; Luz, Rúben; Lage, Sandra; Menezes, Carina; Dias, Elsa; Flores, Cintia; Fonseca, Amélia; Gonçalves, VítorThe morphological plasticity of cyanobacteria and their widespread ecological dominance in a wide range of habitats highlights the need for in-depth taxonomic studies. This work focused on the taxonomical revision of Leptolyngbya (Cyanophyceae) strains deposited in the ESSACC culture collection and their metabolomic characterization. Although the studied ESSACC strains were morphologically identified as Leptolyngbya sp., the 16S rRNA gene and 16S-23S rRNA ITS analysis revealed that two strains (LMECYA 079 and LMECYA 173) belong to Haloleptolyngbya and represent a new taxonomical unit, genetically unique, ecologically plastic and adapted to both freshwater and thermal habitats, here described as Haloleptolyngbya lusitanica sp. nov. To perform a suspect screening of cyanometabolites in these strains, we used a non-targeted liquid chromatography-high resolution mass spectrometry (LC-HRMS) metabolomic approach. Several metabolites were identified in Haloleptolyngbya lusitanica: micropeptin MM978, spumigin 640, oscillatoxin A and anabaenopeptin D. Strains were maintained and grown under the same conditions, revealing the common production of oscillatoxin A by both H. lusitanica strains. Other identified metabolites, however, were strain-specific, such as anabaenoptin D, which was only detected in LMECYA 173. The different cyanometabolite profiles reinforce the notion that cyanobacteria have the ability to adapt to different habitats, which is maintained under long-term culturing conditions.
- Native (Ruditapes decussatus) and non-indigenous (R. philippinarum) shellfish species living in sympatry: Comparison of regulated and non-regulated biotoxins accumulationPublication . Braga, Ana C.; Lage, Sandra; Pacheco, Mario; Rydberg, Sara; Reis Costa, PedroThe native Ruditapes decussatus and the non-indigenous Ruditapes philippinarum are an important target of shellfish industries. The aim of this study was to compare an invader with a native species living in sympatry in the view of marine biotoxins accumulation. Samples were analysed for regulated and non regulated biotoxins. The consistently occurrence of okadaic acid-group toxins and BMAA, may cause human health problems and economical losses. A strong positive relationship was observed between species, with significantly higher DSP toxicity in R. decussatus. Similar toxin profiles dominated by DTX3 in both species suggests similar metabolic pathways. Lower DSP toxicity in R. philippinarum may favour their cultivation, but a tendency for higher levels of the non-regulated BMAA was observed, indicating risks for consumers that are not monitored. This study highlights the need to better understand the physiological responses and adaptations allowing similar species exposed to the same conditions to present different toxicity levels. (C) 2017 Elsevier Ltd. All rights reserved.
- New vectors of TTX analogues in the North Atlantic Coast: the edible crabs Afruca tangeri and Carcinus maenasPublication . Lage, Sandra; ten Brink, Felicitas; Canário, Adelino V. M.; Silva, José Paulo daTetrodotoxin (TTX) and its analogues are naturally occurring toxins historically responsible for human poisoning fatalities in Eastern Asia. It is typically linked to the consumption of pufferfish and, to a lesser extent, marine gastropods and crabs. In the scope of a comprehensive project to understand the prevalence of emergent toxins in edible marine organisms, we report, for the first time, the detection of TTX analogues in the soft tissues of edible crabs, the European fiddler crab (Afruca tangeri) and green crab (Carcinus maenas), harvested in southern Portugal. No TTX was detected in the analyzed samples. However, three TTX analogues were detected—an unknown TTX epimer, deoxyTTX, and trideoxyTTX. These three analogues were found in the European fiddler crab while only trideoxyTTX was found in the green crab, suggesting that the accumulation of TTX analogues might be influenced by the crabs’ different feeding ecology. These results highlight the need to widely monitor TTX and its analogues in edible marine species in order to provide adequate information to the European Food Safety Authority and to protect consumers.
- No β-N-Methylamino-L-alanine (BMAA) was detected in stranded cetaceans from Galicia (North-West Spain)Publication . Soliño, Lucia; Kim, Sea-Yong; López, Alfredo; Covelo, Pablo; Rydberg, Sara; Reis Costa, Pedro; Lage, SandraThe neurotoxin β-N-methylamino-L-alanine (BMAA), a non-proteinogenic amino acid produced by several species of both prokaryotic (cyanobacteria) and eukaryotic (diatoms) microorganisms, has been proposed to be associated with the development of neurodegenerative diseases. At first, BMAA appeared to be ubiquitously present worldwide in various organisms, from aquatic and terrestrial food webs. However, recent studies, using detection methods based on mass spectrometry, instead of fluorescence detection, suggest that the trophic transfer of BMAA is debatable. This study evaluated BMAA in 22 cetaceans of three different species (Phocoena phocoena, n = 8, Delphinus delphis, n = 8, and Tursiops truncatus, n = 6), found stranded in North-West Spain. BMAA analysis of the liver, kidney, or muscle tissues via sensitive liquid chromatography with tandem mass spectrometry did not reveal the presence of this compound or its isomers. The absence recorded in this study highlights the need to better understand the trophic transfer of BMAA and its anatomical distribution in marine mammals.