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Centre for Environmental and Marine Studies
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Exopolysaccharide Production from Marine-Derived Brevundimonas huaxiensis Obtained from Estremadura Spur Pockmarks Sediments Revealing Potential for Circular Economy
Publication . Catalão, Marta; Fernandes, Mafalda; Galdon, Lorena; Rodrigues, Clara F.; Sobral, Rita G.; Gaudêncio, Susana P.; Torres, Cristiana A. V.; DQ - Departamento de Química; DCV - Departamento de Ciências da Vida; UCIBIO - Applied Molecular Biosciences Unit; MDPI - Multidisciplinary Digital Publishing Institute
Marine environments represent an enormous biodiversity reservoir due to their numerous different habitats, being abundant in microorganisms capable of producing biomolecules, namely exopolysaccharides (EPS), with unique physical characteristics and applications in a broad range of industrial sectors. From a total of 67 marine-derived bacteria obtained from marine sediments collected at depths of 200 to 350 m from the Estremadura Spur pockmarks field, off the coast of Continental Portugal, the Brevundimonas huaxiensis strain SPUR-41 was selected to be cultivated in a bioreactor with saline culture media and glucose as a carbon source. The bacterium exhibited the capacity to produce 1.83 g/L of EPS under saline conditions. SPUR-41 EPS was a heteropolysaccharide composed of mannose (62.55% mol), glucose (9.19% mol), rhamnose (19.41% mol), glucuronic acid (4.43% mol), galactose (2.53% mol), and galacturonic acid (1.89% mol). Moreover, SPUR-41 EPS also revealed acyl groups in its composition, namely acetyl, succinyl, and pyruvyl. This study revealed the importance of research on marine environments for the discovery of bacteria that produce new value-added biopolymers for pharmaceutical and other biotechnological applications, enabling us to potentially address saline effluent pollution via a sustainable circular economy.
The diversity, metabolomics profiling, and the pharmacological potential of actinomycetes isolated from the estremadura spur pockmarks (Portugal)
Publication . Pinto-Almeida, António; Bauermeister, Anelize; Luppino, Luca; Grilo, Inês R.; Oliveira, Juliana; Sousa, Joana R.; Petras, Daniel; Rodrigues, Clara F.; Prieto-Davó, Alejandra; Tasdemir, Deniz; Sobral, Rita G.; Gaudêncio, Susana P.; UCIBIO - Applied Molecular Biosciences Unit; DCV - Departamento de Ciências da Vida; MDPI - Multidisciplinary Digital Publishing Institute
The Estremadura Spur pockmarks are a unique and unexplored ecosystem located in the North Atlantic, off the coast of Portugal. A total of 85 marine-derived actinomycetes were isolated and cultured from sediments collected from this ecosystem at a depth of 200 to 350 m. Nine genera, Streptomyces, Micromonospora, Saccharopolyspora, Actinomadura, Actinopolymorpha, Nocardiopsis, Saccharomonospora, Stackebrandtia, and Verrucosispora were identified by 16S rRNA gene sequencing analyses, from which the first two were the most predominant. Non-targeted LC-MS/MS, in combination with molecular networking, revealed high metabolite diversity, including several known metabolites, such as surugamide, antimycin, etamycin, physostigmine, desferrioxamine, ikarugamycin, piericidine, and rakicidin derivatives, as well as numerous unidentified metabolites. Taxonomy was the strongest parameter influencing the metabolite production, highlighting the different biosynthetic potentials of phylogenetically related actinomycetes; the majority of the chemical classes can be used as chemotaxonomic markers, as the metabolite distribution was mostly genera-specific. The EtOAc extracts of the actinomycete isolates demonstrated antimicrobial and antioxidant activity. Altogether, this study demonstrates that the Estremadura Spur is a source of actinomycetes with potential applications for biotechnology. It highlights the importance of investigating actinomycetes from unique ecosystems, such as pockmarks, as the metabolite production reflects their adaptation to this habitat.
Analysis of Zebrafish contamination with heavy metals using a FF-XRF imaging system based on a MPGD
Publication . Leite, F. D.; Carvalho, P. M. S.; Oliveira, R. G.; Lopes, M. C.; Domingues, I.; Correia, P. M. M.; Carramate, L. F. N. D.; Pessanha, S.; Veloso, J. F. C. A.; Silva, A. L. M.; DF – Departamento de Física; LIBPhys-UNL; Elsevier
Heavy metals have been extensively used by humans and are still present in many aspects of modern-day life. Such elements tend to accumulate, degrading the quality of air, soil, and water, negatively affecting the living organisms. As such, it is of paramount importance to understand the environmental risks of heavy metals, including their bioaccumulation capacity in organisms, since they are associated with several harmful health effects, such as neurological damages. The Zebrafish (Danio rerio) has been shown to be an excellent animal model to understand physiological responses in mammals and consequently to perform toxicological studies due to characteristics such as the high genetic and physiological similarity with humans. In this work, a Full-Field Energy Dispersive X-ray Fluorescence (FF-XRF) imaging system, based on the 2D-THCOBRA micropattern gas detector, was used to monitor heavy metal accumulation in Zebrafish during a water borne exposure bioassay. The distributions of Mn, Se, and Pb in Zebrafish, exposed to different concentrations of the heavy metal compounds during different time intervals, were mapped. The results show a preferential accumulation of Mn, Se, and Pb in the Zebrafish's visceral region and highlight the suitability of the FF-XRF imaging system for quick screening of metal accumulation in fish bioassays.
Summer is coming! tackling ocean warming in atlantic salmon cage farming
Publication . Calado, Ricardo; Mota, Vasco C.; Madeira, Diana; Leal, Miguel C.; UCIBIO - Applied Molecular Biosciences Unit; MDPI - Multidisciplinary Digital Publishing Institute
Atlantic salmon (Salmo salar) cage farming has traditionally been located at higher latitudes where cold seawater temperatures favor this practice. However, these regions can be impacted by ocean warming and heat waves that push seawater temperature beyond the thermo-tolerance limits of this species. As more mass mortality events are reported every year due to abnormal sea temperatures, the Atlantic salmon cage aquaculture industry acknowledges the need to adapt to a changing ocean. This paper reviews adult Atlantic salmon thermal tolerance limits, as well as the deleterious eco-physiological consequences of heat stress, with emphasis on how it negatively affects sea cage aquaculture production cycles. Biotechnological solutions targeting the phenotypic plasticity of Atlantic salmon and its genetic diversity, particularly that of its southernmost populations at the limit of its natural zoogeographic distribution, are discussed. Some of these solutions include selective breeding programs, which may play a key role in this quest for a more thermotolerant strain of Atlantic salmon that may help the cage aquaculture industry to adapt to climate uncertainties more rapidly, without compromising profitability. Omics technologies and precision breeding, along with cryopreservation breakthroughs, are also part of the available toolbox that includes other solutions that can allow cage farmers to continue to produce Atlantic salmon in the warmer waters of the oceans of tomorrow.
Thermal tolerance limits and physiological traits as indicators of Hediste diversicolor's acclimation capacity to global and local change drivers
Publication . Fernandes, Joana Filipa; Calado, Ricardo; Jerónimo, Daniel; Madeira, Diana; UCIBIO - Applied Molecular Biosciences Unit; DQ - Departamento de Química; Elsevier Science B.V., Amsterdam.
Global projections predict significant increases in ocean temperature and changes in ocean chemistry, including salinity variations by 2100. This has led to a substantial interest in the study of thermal ecophysiology, as temperature is a major factor shaping marine ectotherm communities. However, responses to temperature may be influenced by other factors such as salinity, highlighting the relevance of multiple stressor studies. In the present work, we experimentally evaluated the thermal tolerance of the marine ragworm Hediste diversicolor under predicted global change scenarios. Organisms were subjected to an experimental trial under control (24 °C), and two temperature treatment scenarios (ocean warming +3 °C – (27 °C) and heat wave +6 °C – (30 °C)), combined with salinity variations (20 and 30) in a full factorial design for 29 days. Environmental data from the field were collected during 2019 and 2020. At day 30 post exposure, upper thermal limits (Critical Thermal Maximum - CTMax), thermal safety margins (TSM) and acclimation capacity were measured. Higher acclimation temperatures led to higher thermal tolerance limits, confirming that H. diversicolor features some physiological plasticity, acclimation capacity and a positive thermal safety margin. This margin was greater considering in situ temperature data from 2019 than maximum temperatures for 2020 (CTMax > maximum habitat temperature–MHT). Moreover, smaller organisms displayed higher upper thermal limits suggesting that thermal tolerance is size dependent. Ragworms subjected to higher salinity also showed a higher CTMax than those acclimated to lower salinity. However, temperature and salinity showed an additive effect on CTMax, as no significant interaction was detected. We conclude that H. diversicolor can easily acclimate to increased water temperature, independently of salinity variations. Given the key role of ragworms in food webs in estuaries and coastal lagoons, substrate bioturbation and aquaculture, this information is relevant to support conservation actions, optimize culture protocols and identify thermal resistant strains.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
6817 - DCRRNI ID
Número da atribuição
UIDB/50017/2020