MARE - Artigos com peer review
URI permanente para esta coleção:
Navegar
Entradas recentes
- Effects of cadmium and resource quality on freshwater detritus processing chains: a microcosm approach with two insect speciesPublication . Campos, Diana; Alves, Artur; Lemos, Marco F. L.; Correia, António; Soares, Amadeu M. V. M.; Pestana, João L. T.Detritus processing is vital for freshwater ecosystems that depend on the leaf litter from riparian vegetation and is mediated by microorganisms and aquatic invertebrates. Shredder invertebrates transform coarse particulate organic matter into fine particulate organic matter used as food by collector species. Direct and indirect effects of contaminants can impair detritus processing and thus affect the functioning of these ecosystems. Here, we assessed the combined effects of a toxic metal (cadmium) and resource quality (leaf species) on detritus processing and shredder-collector interactions. We considered two types of leaves, alder and eucalyptus that were microbially conditioned under different Cd concentrations in the laboratory. The microbial communities present on leaves were analyzed by Denaturing Gradient Gel Electrophoresis (DGGE), and we also measured microbial respiration rates. Sericostoma vittatum (a caddisfly shredder) and Chironomus riparius (a midge collector) were also exposed to Cd and allowed to consume the corresponding alder or eucalyptus leaves. We evaluated C. riparius growth and leaf mass loss in multispecies microcosms. Cadmium exposure affected leaf conditioning and fungal diversity on both leaf species, as assessed by DGGE. Cadmium exposure also affected the mass loss of alder leaves by reductions in detritivore feeding, and impaired C. riparius growth. Chironomus riparius consumed alder leaf discs in the absence of shredders, but S. vittatum appear to promote C. riparius growth in treatments containing eucalyptus. These results show that indirect effects of contaminants along detritus-processing chains can occur through effects on shredder-collector interactions such as facilitation but they also depend on the nutritional quality of detritus and on sensitivity and feeding plasticity of detritivore species.
- Human milk fat substitutes: Advances and constraints of enzyme‐catalyzed productionPublication . Ferreira-Dias, Suzana; Tecelão, CarlaThe production of triacylglycerols (TAGs) with similar structures to the human milk fat TAGs is only possible using sn-1,3 regioselective lipases as biocatalysts. The advances on the processes currently performed for the production of human milk fat substitutes (HMFS), namely the biocatalysts used, the best operation conditions, reactor types and operation modes, as well as the major drawbacks of these enzymatic systems, are addressed in this article.
- C2-Domain Abscisic Acid-Related Proteins Mediate the Interaction of PYR/PYL/RCAR Abscisic Acid Receptors with the Plasma Membrane and Regulate Abscisic Acid Sensitivity in ArabidopsisPublication . Rodriguez, Lesia; Gonzalez-Guzman, Miguel; Diaz, Maira; Rodrigues, Américo; Izquierdo-Garcia, Ana C.; Peirats-Llobet, Marta; Fernandez, Maria A.; Antoni, Regina; Fernandez, Daniel; Marquez, Jose A.; Mulet, Jose M.; Albert, Armando; Rodriguez, Pedro L.Membrane-delimited abscisic acid (ABA) signal transduction plays a critical role in early ABA signaling, but the molecular mechanisms linking core signaling components to the plasma membrane are unclear. We show that transient calcium-dependent interactions of PYR/PYL ABA receptors with membranes are mediated through a 10-member family of C2-domain ABA-related (CAR) proteins in Arabidopsis thaliana. Specifically, we found that PYL4 interacted in an ABA independent manner with CAR1 in both the plasma membrane and nucleus of plant cells. CAR1 belongs to a plant specific gene family encoding CAR1 to CAR10 proteins, and bimolecular fluorescence complementation and coimmunoprecipitation assays showed that PYL4-CAR1 as well as other PYR/PYL-CAR pairs interacted in plant cells. The crystal structure of CAR4 was solved, which revealed that, in addition to a classical calcium-dependent lipid binding C2 domain, a specific CAR signature is likely responsible for the interaction with PYR/PYL receptors and their recruitment to phospholipid vesicles. This interaction is relevant for PYR/PYL function and ABA signaling, since different car triple mutants affected in CAR1, CAR4, CAR5, andCAR9 genes showed reduced sensitivity to ABA in seedling establishment and root growth assays. In summary, we identified PYR/PYL-interacting partners that mediate a transient Ca2+-dependent interaction with phospholipid vesicles, which affects PYR/PYL subcellular localization and positively regulates ABA signaling.
- The golden mackerel: first report of a xanthic Mediterranean horse mackerel Trachurus mediterraneus (Steindachner, 1868) from Sines, PortugalPublication . Vasco-Rodrigues, Nuno; Santos, Simão; Espírito-Santo, Cristina; Almada, FredericoIn this study, a single xanthic case of the Mediterranean horse mackerel Trachurus mediterraneus is reported. The individual, with a total lenght (TL) of 306 mm, was captured off Sines (Portugal) in March 2018, by a local fishing boat, using a seine net. This represents the first record of xanthism for this species and for any species of mackerel. The specimen is described here and compared with those of normal pigmentation. Considerations about the paucity of records for this or similar species are presented here, and the possibility of this condition being more frequent than previously thought is discussed.
- Seasonal Variation in Proximate Composition and Fatty Acid Profile of Grey Triggerfish Balistes capriscus Captured Along the Coast of PortugalPublication . Simões, Tiago; Carvalho, João; Sousa, Ana; Lemos, Marco F. L.; Gil, Maria M.; Pedrosa, Rui; Tecelão, CarlaProximate composition (ash, moisture, total protein, and fat contents) and fatty acid profile of Balistes capriscus (grey triggerfish) were assessed over a 6-months period (April to September, 2011) in animals captured along the coast of Peniche (Portugal). High protein (18.9% to 21.4%) and low lipid (0.5% to 0.8%) contents were determined. The highest lipid level was found in June-captured animals. High proportions of n-3 polyunsaturated fatty acids (n-3 PUFA) were observed (53.87 ± 2.00%) together with substantial quantities of oleic acid (27.58 ± 1.09%) and palmitic acid (16.52 ± 0.93%). Docosahexaenoic acid accounted for 77% of the total PUFA and was 7 times more abundant than eicosapentaenoic acid, and the n-3/n-6 ratio was 7.2. Gender did not influence lipid levels and the fatty acid profile, but seasonal variations were observed for PUFA and monounsaturated fatty acid contents. Overall, the nutritional properties of this underexploited species may be comparable to those of other lean fish species with higher economic value. Practical Application: Balistes capriscus is an abundant species in the Atlantic and underexploited in the Eastern Atlantic coast, with very few studies reported. This study was aimed to add commercial value to the species through its nutritional evaluation. B. capriscus is characterized by high protein and low fat contents. High proportions of n-3 PUFA, mainly docosahexaenoic acid, were noted for the grey triggerfish. Nutritional properties of this species may be comparable to those of other lean fish species.
- Metabolic Profile of Four Selected Cathinones in Microsome Incubations: Identification of Phase I and II Metabolites by Liquid Chromatography High Resolution Mass SpectrometryPublication . Lopes, Beatriz T.; Caldeira, Maria João; Gaspar, Helena; Antunes, Alexandra M. M.Consumption of synthetic cathinones, the second largest class of new psychoactive substances (NPS) reported worldwide, represents a serious public health risk. One of the biggest challenges created by the rapid spread of NPS on the illegal drug market is the discovery of selective biomarkers for their detection in biological matrices, which is only possible through the study of their metabolic profile. The synthetic cathinones 4′-methyl-N,N-dimethylcathinone (4-MDMC), 4′-methyl-N,N-diethylcathinone (4-MDEC), 4′-chloro-α-pyrrolidinovalerophenone (4Cl-PVP), and 4′-chloroethylcathinone (4-CEC) are NPS recently seized in Europe, and, with the exception of 4-CEC, no metabolism study was reported for these cathinones. With the ultimate goal of overcoming this gap, these cathinones were incubated in vitro in human and rat liver microsomes in the presence of Phase I and II (glucuronidation) co-factors, using α-pyrrolidinovalerophenone (α-PVP) as positive control. The metabolite identification was performed by liquid chromatography coupled to tandem high resolution mass spectrometry (LC-HRMS/MS). This allowed the identification of multiple Phase I and glucuronide metabolites of the selected cathinones. Additionally, a new glucuronide conjugate, derived from the recreational drug α-PVP, was herein identified for the first time. Importantly, we have demonstrated that 4-MDMC and 4-MDEC can act as prodrugs of the controlled substances 4-MMC and 4-MEC, respectively. The metabolites herein identified are expected to play an important role not only by acting as potential selective biomarkers of the intake of the synthetic cathinones selected for this study but also to understand their potential adverse effects and link these causative agents to toxicities, thereby helping in the treatment of non-fatal intoxications.
- Assessment of the Levels of Pollution and of Their Risks by Radioactivity and Trace Metals on Marine Edible Fish and Crustaceans at the Bay of Bengal (Chattogram, Bangladesh)Publication . Biswas, Krishna Prasad; Hossain, Shahadat; Deb, Nipa; Bhuian, A.K.M. Saiful Islam; Gonçalves, Sílvia C.; Hossain, Shahadat; Hossen, Mohammad BelalMarine environmental pollution is a longstanding global problem and has a particular impact on the Bay of Bengal. Effluent from different sources directly enters rivers of the region and eventually flows into the Bay of Bengal. This effluent may contain radioactive materials and trace metals and pose a serious threat to the coastal environment, in addition to aquatic ecosystems. Using gamma spectrometry and atomic absorption spectrometry, a comprehensive study was carried out on the radioactivity (226Ra, 232Th, 40K, and 137Cs) and trace metal (Cd, Pb, Zn, Cu, Ni, Fe, Mn, and Cr) concentrations, respectively, in fish and crustacean species collected from the coastal belt of the Bay of Bengal (Chattogram, Bangladesh). The analysis showed a noticeable increment in the levels of different radioactive pollutants in the marine samples, although the consumption of the studied fish and crustacean species should be considered safe for human health. Anthropogenic radionu-clide (137Cs) was not detected in any sample. Furthermore, the metal concentrations of a small num-ber of trace elements (Pb, Cd, Cr) were found to be higher in most of the samples, which indicates aquatic fauna are subject to pollution. The estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TR) were calculated and compared with the per-missible safety limits. It was found that consuming the seafood from the Bay of Bengal may cause adverse health impacts if consumption and/or means of pollution are not controlled.
- EditorialPublication . Novais, Sara C.; Maranhão, Paulo
- Development of a new multiplex-PCR tool for the simultaneous detection of the fish pathogens Vibrio alginolyticus, Vibrio anguillarum, Vibrio harveyi and Edwardsiella tardaPublication . Pinto, Micaela Ferreira; Baptista, Teresa; Afonso, Clélia Correia NevesDisease assessment and management in cultured aquatic animals is a major concern in commercial aquaculture. Disease outbreaks have direct effects on fish production, causing serious economic losses in this industry. This can be overcome by early detection through molecular high sensitivity tools such as PCR (polymerase chain reaction). One of the most critical steps in the study of bacterial fish diseases is the precise identification of the infectious agent. Considering the damage that some bacteria can cause to fish and humans, the development of a rapid detection method for the four target species that demonstrates to be simple, accurate and low cost is an essential step for the prevention and early treatment of these diseases. Edwardsiella tarda (ACC 36.1), Vibrio harveyi (DSM 19023), Vibrio anguillarum (AQV 55.1) and Vibrio alginolyticus (CECT 521) were selected as targets of a multiplex PCR tool. The multiplex PCR reactions were performed in various reaction conditions, including different annealing temperatures (between 49 °C and 55 °C) and changes in the MgCl2 concentration from 2mMto 8 mM. Best results were obtained at 51 °C and MgCl2 concentration from 4mM to 6 mM. Primers were tested using purified DNA from the respective bacterial strains, yielding bands at expected sizes, which can be identified on agarose gels with clearness and without overlapping sizes. Results indicate that this multiplex PCR tool is suitable for the detection of target pathogens and may, in the future, have extended practical application in commercial aquaculture.
- Cleaning interactions of fishes at São Tomé Island, West AfricaPublication . Vasco Rodrigues, Nuno; Fontes, Jorge; Bertoncini, A.This study reports six new types of cleaning interactions among tropical reef fish species at São Tomé Island, and confirms previously reported interactions for this area. Spicara melanurus was recorded as a cleaner for the first time, and Abudefduf saxatilis was confirmed in this role, following reports from the Southwest Atlantic. Individuals belonging to the family Labridae were the most commonly-observed cleaners, involved in over 85% of recorded interactions. Juveniles of Bodianus speciosus played a key role as cleaners, interacting with at least seven client species. In addition, some of the client fishes, including Paranthias furcifer and Acanthurus monroviae, interacted with at least four cleaner fish species. All cleaner fish species reported in this study were facultative; obligate cleaners appear to be absent from this region.