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Browsing ESTM - Artigos em revistas internacionais by Sustainable Development Goals (SDG) "12:Produção e Consumo Sustentáveis"
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- Anti-Hepatocellular Carcinoma (HepG2) Activities of Monoterpene Hydroxy Lactones Isolated from the Marine Microalga Tisochrysis LuteaPublication . Gangadhar, Katkam N.; Rodrigues, Maria João; Pereira, Hugo; Gaspar, Helena; Malcata, F. Xavier; Barreira, Luísa; Varela, JoãoTisochrysis lutea is a marine haptophyte rich in omega-3 polyunsaturated fatty acids (e.g., docosahexaenoic acid (DHA)) and carotenoids (e.g., fucoxanthin). Because of the nutraceutical applications of these compounds, this microalga is being used in aquaculture to feed oyster and shrimp larvae. In our earlier report, T. lutea organic crude extracts exhibited in vitro cytotoxic activity against human hepatocarcinoma (HepG2) cells. However, so far, the compound(s) accountable for the observed bioactivity have not been identified. Therefore, the aim of this study was to isolate and identify the chemical component(s) responsible for the bioactivity observed. Bioassay-guided fractionation through a combination of silica-gel column chromatography, followed by preparative thin layer chromatography (PTLC), led to the isolation of two diastereomers of a monoterpenoid lactone, namely, loliolide (1) and epi-loliolide (2), isolated for the first time in this species. The structural elucidation of both compounds was carried out by GC-MS and 1D (1 H and13 C APT) and 2D (COSY, HMBC, HSQC-ed, and NOESY) NMR analysis. Both compounds significantly reduced the viability of HepG2 cells and were considerably less toxic towards a non-tumoral murine stromal (S17) cell line, although epi-loliolide was found to be more active than loliolide. © 2020 by the authors.
- Asparagopsis armata and Sphaerococcus coronopifolius as a natural source of antimicrobial compoundsPublication . Pinteus, Susete; Alves, Celso; Monteiro, Hugo; Ernesto Araújo; Horta, André; Pedrosa, RuiMethanol, n-hexane and dichloromethane extracts of twelve marine macro-algae (Rhodophyta, Chlorophyta and Heterokontophyta divisions) from Peniche coast (Portugal) were evaluated for their antibacterial and antifungal activity. The antibacterial activity was evaluated by disc diffusion method against Bacillus subtilis (gram positive bacteria) and Escherichia coli (gram negative bacteria). Saccharomyces cerevisiae was used as a model for the antifungal activity by evaluating the growth inhibitory activity of the extracts. The high antibacterial activity was obtained by the Asparagopsis armata methanolic extract (10 mm–0.1 mg/disc), followed by the Sphaerococcus coronopifoliusn-hexane extract (8 mm–0.1 mg/disc), and the Asparagopsis armata dichloromethane extract (12 mm–0.3 mg/disc) against Bacillus subtilis. There were no positive results against Escherichia coli. Sphaerococcus coronopifolius revealed high antifungal potential for n-hexane (IC50 = 40.2 µg/ml), dichloromethane (IC50 = 78.9 µg/ml) and methanolic (IC50 = 55.18 µg/ml) extracts against Saccharomyces cerevisiae growth. The antifungal potency of the Sphaerococcus coronopifolius extracts was similar with the standard amphotericin B. Asparagopsis armata and Sphaerococcus coronopifolius reveal to be interesting sources of natural compounds with antimicrobial properties. © 2015, Springer Science+Business Media Dordrecht.
- Assessement and management of environmental quality conditions in marine sandy beaches for its sustainable use—Virtues of the population based approachPublication . Gonçalves, Sílvia C.; Marques, João C.Sandy beaches constitute high natural value ecosystems which have been worldwide a target for growing human activities and ensuing pressures in the last decades, which caused ecological damages on these environments and led to its environmental quality decline. However, little is known about the responses of these ecosystems to distinct stressors and pressures, and holistic and integrated coastal management actions that protect beach environments and their ecological processes are yet to be developed. The aim of this viewpoint article is to present and discuss the utility of using a population approach to macrofaunal key species as a helpful tool for the assessment, management, and sustainable use of sandy beaches. The role of macrofaunal key species as indicators of environmental changes and of ecological quality condition is discussed and illustrated by some practical examples from the literature. The population is presented as a highly relevant ecological unit in management and one of the easiest ones to use, responding more rapidly to disturbances in the ecosystem than the most complex units. In this context, bio-ecology and population dynamics models are presented as tools and their potential, to improve the way we assess and manage ecological quality conditions of beach ecosystems aiming at its sustainable use, are discussed. Also, the advantages and drawbacks of the use of these tools in the population approach are evaluated. Monitoring, assessment and management practices focusing on beach key species bioecology as ecological indicator hold large potential in nowadays fast changing scenario, and should be encouraged as a function of their identifiable responses to manmade and natural disturbances.
- Bifurcaria bifurcata: a key macro‐alga as a source of bioactive compounds and functional ingredientsPublication . Alves, Celso; Pinteus, Susete; Simões, Tiago; Horta, André; Silva, Joana; Tecelão, Carla; Pedrosa, RuiThe aim of this work was to study the proximate composition and the bioactive profile of Bifurcariabifurcata. It contains 73.31 0.69% of moisture, 8.57 0.11 g per 100 g dry weight (d.w.) of protein,5.81 0.14 g per 100 g d.w. of lipid content and 30.15 0.00 g per 100 g d.w. of ash. The polyunsatu-rated fatty acids were the most abundant fatty acid (FA), accounting for 2426.56 mg per 100 g which rep-resents 41.77% of the total FA. The methanolic fraction showed high quantity of polyphenols (220.01 0.010 phloroglucinol equivalents g 1 extract), DPPH radical reduction capacity (EC 50:58.82 lg mL 1)and oxygen radical absorbent capacity (3151.35 119.33 lmol Trolox equivalents g 1 extract). Thehighest antimicrobial effect was observed against Pseudomonas aeruginosa (11.3 1.5 mm) and Sac-charomyces cerevisiae (IC 50 :17.07 lg mL 1 ) induced by methanolic and dichloromethane fractions,respectively. Dichloromethane fraction revealed the highest antitumor activity on Caco-2 and HepG-2 cells. Bifurcaria bifurcata can be a promising source of bioactive compounds and functionalingredients.
- Bioaccumulation and Elimination of Waterborne Mercury in the Midge Larvae, Chironomus riparius Meigen (Diptera: Chironomidae)Publication . Azevedo-Pereira, Henrique M. V. S.; Abreu, Sizenando N.; Lemos, Marco F.L.; Soares, Amadeu M. V. M.Here, mercury kinetics and behavioural effects in the midge larvae under a water-only exposure were assessed. Uptake and elimination of waterborne mercury were described by using a one-compartment kinetic model. Results show that midges were able to readily accumulate the heavy metal (BCF = 450), presenting a fast uptake, up to 13.1 lg Hg g of animal-1 at the end of the exposure period. Elimination was slow, with c.a. 39 % of the mercury in larvae being depurated after 48 h in clean medium. Behaviour did not present differences upon exposure or elimination, but a trend to increase ventilation was noticed during the exposure period.
- Bioproducts from forest biomass II. Bioactive compounds from the steam-distillation by-products of Cupressus lusitanica Mill. and Cistus ladanifer L. wastesPublication . Tavares, Cláudia S.; Martins, Alice; Miguel, M. Graça; Carvalheiro, Florbela; Duarte, Luís C.; Gameiro, José A.; Figueiredo, A. Cristina; Roseiro, Luísa B.Obtaining essential oils and hydrolates from underutilized biomass is an economic and sustainable way for production of these high added-value bioproducts. However, this process still generates large amounts of residues as the by-products obtained during distillation, which can be a concern for the environment, but also adequate substrates for other applications. Considering this fact, the waste distilled by-products remaining after steam-distillation of underutilized biomass from Cupressus lusitanica and Cistus ladanifer, were evaluated as a natural source of other high value products with biological activities, namely, phenolic compounds. Thus, the remaining extracted solid residues (ESRs) were characterized and subject to further treatments by ultrasound-assisted extraction (UAE) with ethanol and 70 % acetone, in order to prepare phenolic-rich extracts thereof: ESRs(EtOH) and ESRs(70 % Ace). Together with the distiller condensation waters (DCWs), these extracts were characterized for their phenolic content (total phenols, tannins and flavonoids). Their antioxidant activity was also evaluated by different methodologies. The phenolic profile of DCWs, ESRs(EtOH) and ESRs(70 % Ace) from both waste species was obtained by capillary zone electrophoresis (CZE) and phenolic compounds were tentatively identified. Results obtained for C. lusitanica biomass are here disclosed for the first time. Generally, all samples revealed to be rich in phenolic compounds, being C. ladanifer biomass the one with higher phenolic content. DCWs presented values of 140 mgGAE/g for C. lusitanica and 210 mg GAE/g for C. ladanifer, from which ca. 60 % were tannins. Extracts obtained with 70 % acetone were the ones with the highest results, except for the antioxidant activity by xanthine oxidase and superoxide inhibition, which was higher in DCWs. Catechins were the major compounds found for both species, but gallocatechins and gallic acid were only identified in C. ladanifer. Hydroxycinnamic acid derivatives and salicylic acid were also identified in C. ladanifer, partly justifying the anti-inflammatory effect referred for this species.
- Bioremediation of Synthetic Wastewater with Contaminants of Emerging Concern by Nannochloropsis sp. and Lipid Production: A Circular ApproachPublication . Santos, Bruna; Araújo, Juliana; Carvalho, Beatriz; Cotrim, Carolina; Bernardino, Raul; Freitas, Filomena; Sobral, Abílio J. F. N.; Encarnação, TelmaContaminants of emerging concern (CECs) pose a potential risk to human and environmental health. Microalgae bioremediation is a promising approach for transforming or removing contaminants from the environment, while contributing to the circular economy. In this study, Nannochloropsis sp. was effectively used for the simultaneous removal of six CECs: paracetamol, ibuprofen, imidacloprid, methylparaben and bisphenol A at 10 µg mL−1 and triclosan at 0.5 µg mL−1 from synthetic wastewater, which were able to survive under such concentrations, higher than those commonly found in the environment (up to 2.82 µg mL−1 of methylparaben). High removal efficiencies were reached for methylparaben (100%) and bisphenol A (93 ± 2%), while for imidacloprid, paracetamol and ibuprofen, 30 ± 1%, 64 ± 2% and 49 ± 5% were removed, respectively. Subsequently, lipids were extracted, and the FAME profile was characterised using GS-MS. The main fatty acids identified after bioremediation were hexadecadienoic acid isomers (C16:2), palmitic acid (C16), linoleic acid (C18:2) and γ-linolenic acid (C18:3). The absence of oleic acid and stearic acid was noticed, suggesting an alteration in the lipidic profile due to contaminant exposure. By exploring the quantification of fatty acids in future work, potential applications for the extracted lipids can be explored, further demonstrating the feasibility of this circular process.
- Broodstock conditioning of the Portuguese oyster (Crassostrea angulata, Lamarck, 1819): influence of different dietsPublication . Anjos, Catarina; Baptista, Teresa; Joaquim, Sandra; Mendes, Susana; Matias, Ana Margarete; Moura, Paula; Simões, Tiago; Matias, DomitíliaThe Portuguese oyster Crassostrea angulata shows great potential in oyster farming. The conservation of pure populations of this species is important for production diversification and biodiversity preservation. In this way, the zootechnological development for seed hatchery production is extremely important. Broodstock conditioning is a key step in the process of rearing bivalves in a hatchery. Many factors regulate the reproductive cycle, being food one of the most important ones. To evaluate the effect of different diets on C. angulata reproductive performance, broodstock were conditioned with different food regimes formulated fundamentally by flagellates (Diet 1 – Pavlova lutheri and Isochrysis galbana clone T-ISO; Diet 2 – P. lutheri, T-ISO and Skeletonema costatum) and constituted fundamentally by diatoms (Diet 3 – S. costatum and Chaetoceros calcitrans; Diet 4 – P. lutheri, S. costatum and C. calcitrans). During conditioning, samples of oysters were collected to evaluate condition index, gonadal development and biochemical composition. At the end of the conditioning period, oysters were induced to spawn to evaluate reproductive output (fecundity, fertilization rate and D-larvae development). The diets had an impact on the gametogenesis process, energy storage and reproductive output performance, being the best results those obtained in broodstock fed with the diatoms-predominant diets. However, those fed with diets majority flagellates had an unsuccessful performance. Holistic approaches incorporating all results in this study reveal and reinforce the idea that the diatom species used presented the nutritional requirements to C. angulata broodstock, being essential in the conditioning phase.
- Camelina oil as a source of polyunsaturated fatty acids for the production of human milk fat substitutes catalyzed by a heterologous Rhizopus oryzae lipasePublication . Faustino, Ana Rita; Osório, Natália M.; Tecelão, Carla; Canet, Albert; Valero, Francisco; Ferreira‐Dias, SuzanaThis study aims to produce human milk fat substitutes (HMFS) rich in polyunsaturated fatty acids (PUFA),mainly the essential omega-3 linolenic acid, by acidolysis reaction between tripalmitin (PPP) and free fattyacids (FFA) from camelina oil, in stirred batch reactor and solvent-free media. The non-commercialheterologous Rhizopus oryzae lipase (rROL), immobilized on Lewatit VP OC 1600 or on Relizyme OD403/S, and the immobilized commercial lipase from Rhizomucor miehei (Lipozyme RM IM) were tested asbiocatalysts. Both lipases are sn-1,3 selective. After 24 h reaction at 60°C, using biocatalyst loads of 5 wt%(in relation to tripalmitin), 48.9, 43.6, and 18.3 mol% of fatty acid incorporation in triacylglycerols (TAG)were obtained with Lipozyme RM IM and rROL immobilized on Lewatit or on Relizyme, respectively.rROL immobilized on Lewatit was selected as biocatalyst for the acidolysis, as alternative to the commercialimmobilized lipases. With this biocatalyst, the molar incorporation increased with its initial water activity(0.55–0.95). Modeling acidolysis catalyzed by rROL immobilized on Lewatit was performed by responsesurface methodology, as a function of temperature (58–72°C) and molar ratio FFA:PPP (1.2:1–6.8:1). Thehighest PPP consumption was achieved at 60°C with a molar ratio of 2:1. The yield of HMFS (new TAG)increased from 42.6 wt% (5% biocatalyst load) to 52% with 8% load, after 24 h acidolysis.Practical applications: Camelina oil showed to be a good source of PUFA, mainly essential fatty acids,to incorporate in HMFS. After 24 h acidolysis under optimized conditions, catalyzed by the non-commercial sn-1,3 regioselective rROL immobilized on Lewatit VP OC 1600, the TAG fraction contains67.7 mol% of palmitic acid at position 2. These structured lipids rich in PUFA can be used in blends with1,3-dioleoyl-2-palmitoyl-glycerol (OPO) in order to mimic the human milk fat. The performance of thisbiocatalyst was comparable to that observed with Lipozyme RM IM. The replacement of high-costcommercial immobilized lipases by rROL immobilized on Lewatit may reduce the biocatalyst cost. Inaddition, since the best molar ratio FFA:PPP for rROL is 2:1, i.e., the stoichiometric value for theacidolysis catalyzed by sn-1,3 regioselective lipases, the use of this biocatalyst will reduce downstreamcosts related with unconverted FFA recovery.
- CO-tucker: a new method for the simultaneous analysis of a sequence of paired tablesPublication . MENDES, SUSANA; Fernández-Gómez, M. José; Cotrim Marques, Sónia; Pardal, Miguel Ângelo; Azeiteiro, Ulisses Miranda; Galindo-Villardón, M. PurificaciónRelationships between species and their environment are a key com ponent to understand ecological communities. Usually, this kind of data are repeated over time or space for communities and their envi ronment, which leads to a sequence of pairs of ecological tables, i.e. multi-way matrices. This work proposes a new method which is a combined approach of STATICO and Tucker3 techniques and deals to the problem of describing not only the stable part of the dynamics of structure–function relationships between communities and their environment (in different locations and/or at different times), but also the interactions and changes associated with the ecosystems’ dynamics. At the same time, emphasis is given to the comparison with the STATICO method on the same (real) data set, where advan tages and drawbacks are explored and discussed. Thus, this study produces a general methodological framework and develops a new technique to facilitate the use of these practices by researchers. Fur thermore, from this first approach with estuarine environmental data one of the major advantages of modeling ecological data sets with the CO-TUCKER model is the gain in interpretability.