Browsing by Author "Pereira, Hugo"
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- A comparative evaluation of biological activities and bioactive compounds of the seagrasses Zostera marina and Zostera noltei from southern PortugalPublication . Custódio, Luísa; Laukaityte, Simona; Engelen, Aschwin; Rodrigues, Maria Joao; Pereira, Hugo; Vizetto-Duarte, C; Barreira, Luísa; Rodriguez, Hortensia; Albericio, Fernando; Varela, JoãoThis work assessed the antioxidant potential, acetylcholinesterase (AChE) inhibition and the in vitro cytotoxic activity of extracts of the seagrasses Zostera marina and Zostera noltei collected from southern Portugal. The total phenolic contents (TPCs), the rosmarinic acid (RA) concentration (HPLC/DAD) and the fatty acid (FA) profile (GC/MS) are also described. Z. marina had the highest TPC, radical scavenging activity against DPPH radicals and copper chelating activity. Z. noltei had metal chelation capacity to copper and iron ions. None of the species was able to inhibit AChE. Both seagrasses had high levels of polyunsaturated FAs. Z. marina significantly and selectively reduced the viability of tumorous neuronal cells. Z. noltei was highly toxic for the three cell lines tested and was selective against hepatocarcinoma cells at the concentration of 100g/mL. RA was the main compound identified in Z. marina, but not in Z. noltei.
- Algae as food in Europe: an overview of species diversity and their applicationPublication . Mendes, Madalena; Navalho, Sofia; Ferreira, Alice; Paulino, Cristina; Figueiredo, Daniel; Silva, Daniel; Gao, Fengzheng; Gama, Florinda; Bombo, Gabriel; Jacinto, Rita; Aveiro, Susana; Schulze, Peter S.C.; Gonçalves, Ana Teresa; Pereira, Hugo; Gouveia, Luisa; Patarra, Rita F.; Abreu, Maria Helena; Silva, Joana L.; Navalho, João; Varela, João; Galileu Speranza, LaisAlgae have been consumed for millennia in several parts of the world as food, food supplements, and additives, due to their unique organoleptic properties and nutritional and health benefits. Algae are sustainable sources of proteins, minerals, and fiber, with well-balanced essential amino acids, pigments, and fatty acids, among other relevant metabolites for human nutrition. This review covers the historical consumption of algae in Europe, developments in the current European market, challenges when introducing new species to the market, bottlenecks in production technology, consumer acceptance, and legislation. The current algae species that are consumed and commercialized in Europe were investigated, according to their status under the European Union (EU) Novel Food legislation, along with the market perspectives in terms of the current research and development initiatives, while evaluating the interest and potential in the European market. The regular consumption of more than 150 algae species was identified, of which only 20% are approved under the EU Novel Food legislation, which demonstrates that the current legislation is not broad enough and requires an urgent update. Finally, the potential of the European algae market growth was indicated by the analysis of the trends in research, technological advances, and market initiatives to promote algae commercialization and consumption.
- Alternative sources of n-3 long-chain polyunsaturated fatty acids in marine microalgaePublication . Martins, Dulce Alves; Custodio, Luisa; Barreira, Luísa; Pereira, Hugo; Ben-Hamadou, Radhouan; Varela, João; Abu-Salah, Khalid M.The main source of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in human nutrition is currently seafood, especially oily fish. Nonetheless, due to cultural or individual preferences, convenience, geographic location, or awareness of risks associated to fatty fish consumption, the intake of fatty fish is far from supplying the recommended dietary levels. The end result observed in most western countries is not only a low supply of n-3 LC-PUFA, but also an unbalance towards the intake of n-6 fatty acids, resulting mostly from the consumption of vegetable oils. Awareness of the benefits of LC-PUFA in human health has led to the use of fish oils as food supplements. However, there is a need to explore alternatives sources of LC-PUFA, especially those of microbial origin. Microalgae species with potential to accumulate lipids in high amounts and to present elevated levels of n-3 LC-PUFA are known in marine phytoplankton. This review focuses on sources of n-3 LC-PUFA, namely eicosapentaenoic and docosahexaenoic acids, in marine microalgae, as alternatives to fish oils. Based on current literature, examples of marketed products and potentially new species for commercial exploitation are presented.
- Anti-Hepatocellular Carcinoma (HepG2) activities of Monoterpene Hydroxy Lactones isolated from the Marine Microalga Tisochrysis LuteaPublication . Gangadhar, Katkam N.; Rodrigues, Maria Joao; 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 (1H and 13C 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.
- Assessment and comparison of the properties of biodiesel synthesized from three different types of wet microalgal biomassPublication . Gangadhar, Katkam N.; Pereira, Hugo; Diogo, Herminio P.; Borges dos Santos, R. M.; Devi, B. L. A. Prabhavathi; Prasad, R. B. N.; Custódio, Luísa; Xavier Malcata, F.; Varela, João; Barreira, LuísaIn recent years, microalgae-based carbon-neutral biofuels (i.e., biodiesel) have gained considerable interest due to high growth rate and higher lipid productivity of microalgae during the whole year, delivering continuous biomass production as compared to vegetable-based feedstocks. Therefore, biodiesel was synthesized from three different microalgal species, namely Tetraselmis sp. (Chlorophyta) and Nannochloropsis oculata and Phaeodactylum tricornutum (Heterokontophyta), and the fuel properties of the biodiesel were analytically determined, unlike most studies which rely on estimates based on the lipid profile of the microalgae. These include density, kinematic viscosity, total and free glycerol, and high heating value (HHV), while cetane number (CN) and cold filter plugging point (CFPP) were estimated based on the fatty acid methyl ester profile of the biodiesel samples instead of the lipid profile of the microalgae. Most biodiesel properties abide by the ASTM D6751 and the EN 14214 specifications, although none of the biodiesel samples met the minimum CN or the maximum content of polyunsaturated fatty acids with a parts per thousand yen4 double bonds as required by the EN 14214 reference value. On the other hand, bomb calorimetric experiments revealed that the heat of combustion of all samples was on the upper limit expected for biodiesel fuels, actually being close to that of petrodiesel. Post-production processing may overcome the aforementioned limitations, enabling the production of biodiesel with high HHV obtained from lipids present in these microalgae.
- Bioactive lipids in : implications for functional foods and healthPublication . Pais, Rita; Conde, Tiago; Neves, Bruna B.; Pinho, Marisa; Coelho, Marta; Pereira, Hugo; Rodrigues, Alexandre M. C.; Domingues, Pedro; Gomes, Ana Maria; Urbatzka, Ralph; Domingues, Rosário; Melo, TâniaDunaliella salina is a green microalga extensively explored for β-carotene production, while knowledge of its lipid composition is still limited and poorly investigated. Among lipids, polar lipids have been highlighted as bioactive phytochemicals with health-promoting properties. This research aimed to provide an in-depth lipidome profiling of using liquid and gas chromatography coupled with mass spectrometry. The lipid content was 6.8%, including phospholipids, glycolipids, betaine lipids, sphingolipids, triglycerides, diglycerides, and pigments. Among the total esterified fatty acids, 13.6% were 18:3 omega-3 and 14.7% were 18:1 omega-9. The lipid extract of showed anti-inflammatory activity by inhibiting cyclooxygenase-2 activity at 100 µg/mL, dose-dependent antioxidant scavenging activity, and antidiabetic activity by inhibiting α-glucosidase activity at 25 and 125 µg/mL. In conclusion, the lipid extract of has the potential to be used as a functional food ingredient or in the nutraceutical and cosmeceutical industries.
- Biological activities and chemical composition of methanolic extracts of selected Autochthonous microalgae strains from the Red SeaPublication . Pereira, Hugo; Custodio, Luisa; Rodrigues, Maria Joao; Bruno De Sousa, Carolina; Oliveira, Marta; Barreira, Luísa; Neng, Nuno da Rosa; Florencio Nogueira, Jose Manuel; Alrokayan, Salman A.; Mouffouk, Fouzi; Abu-Salah, Khalid M.; Ben-Hamadou, Radhouan; Varela, JoãoFour lipid-rich microalgal species from the Red Sea belonging to three different genera (Nannochloris, Picochlorum and Desmochloris), previously isolated as novel biodiesel feedstocks, were bioprospected for high-value, bioactive molecules. Methanol extracts were thus prepared from freeze-dried biomass and screened for different biological activities. Nannochloris sp. SBL1 and Desmochloris sp. SBL3 had the highest radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, and the best copper and iron chelating activities. All species had potent butyrylcholinesterase inhibitory activity (>50%) and mildly inhibited tyrosinase. Picochlorum sp. SBL2 and Nannochloris sp. SBL4 extracts significantly reduced the viability of tumoral (HepG2 and HeLa) cells with lower toxicity against the non-tumoral murine stromal (S17) cells. Nannochloris sp. SBL1 significantly reduced the viability of Leishmania infantum down to 62% (250 mu g/mL). Picochlorum sp. SBL2 had the highest total phenolic content, the major phenolic compounds identified being salicylic, coumaric and gallic acids. Neoxanthin, violaxanthin, zeaxanthin, lutein and -carotene were identified in the extracts of all strains, while canthaxanthin was only identified in Picochlorum sp. SBL2. Taken together, these results strongly suggest that the microalgae included in this work could be used as sources of added-value products that could be used to upgrade the final biomass value.
- Bioprospecting autochthonous marine microalgae strain from the Arabian Gulf Seawater, Kuwait for biofuel feedstocksPublication . Al-Hamar, Bader; R Inbamani, Anandavalli; Komona, Saad A.; Fouzi, Mouffouk; Ben-Hamadou, Radhouane; Pereira, Hugo; Bumajdad, AliBioprospecting programs are the key to increasing the current portfolio of indigenous microalgal strains accessible for different applications in microalgal biotechnology. In this work, nine fast-growing microalgal strains isolated from Kuwait's Arabian/Persian Gulf coastal waters were evaluated for their potential as biofuel feedstocks. 18S rRNA gene sequencing showed that the strains belong to five different genera: Chlorella, Nannochloris, Scenedesmus, Tetraselmis, and Nannochloropsis. In terms of the total lipid content, in comparison to the other strains, Tetraselmis sp. KUBS13G and Tetraselmis sp. KUBS16G displayed higher lipid contents of 29.56% dry weight (DW) and 26.13% DW, respectively, dominated by palmitic and oleic acids. Fuel properties calculated from the fatty acid methyl esters (FAMES) by empirical equations were compared with EN14214 (European) and ASTM D6751--02 (American) biodiesel standards. Multicriteria decision analysis (MCDA) methods, such as the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) and Graphical Analysis for Interactive Assistance (GALA), were used to select suitable microalgae for biofuel feedstock based on their biodiesel fuel properties. Overall, the results suggested that the indigenous microalgal strain Tetraselmis, particularly Tetraselmis sp. KUBS37G, and Scenedesmus sp. KUB Sl7R are the most suitable strains for biofuel feedstock owing to their improved fuel properties, such as density (rho) (0.88 g cm-3), low kinematic viscosity (3.1 mm2 s-1), high cetane number (54 and 56, respectively), high oxidation stability (14.6 hr and 14.8 hr), and cold filter plugging point (1.0 degrees C and -6.1 degrees C).
- Bioprospecting for industrially relevant exopolysaccharide-producing cyanobacteria under portuguese simulated climatePublication . Cruz, José Diogo; Delattre, Cédric; Felpeto, Aldo Barreiro; Pereira, Hugo; Pierre, Guillaume; Morais, João; Petit, Emmanuel; Silva, Joana; Azevedo, Joana; Elboutachfaiti, Redouan; Maia, Inês Beatriz; Dubessay, Pascal; Michaud, Philippe; Vasconcelos, VitorCyanobacterial exopolysaccharides (EPS) are potential candidates for the production of sustainable biopolymers. Although the bioactive and physicochemical properties of cyanobacterial-based EPS are attractive, their commercial exploitation is limited by the high production costs. Bioprospecting and characterizing novel EPS-producing strains for industrially relevant conditions is key to facilitate their implementation in various biotechnological applications and fields. In the present work, we selected twenty-five Portuguese cyanobacterial strains from a diverse taxonomic range (including some genera studied for the first time) to be grown in diel light and temperature, simulating the Portuguese climate conditions, and evaluated their growth performance and proximal composition of macronutrients. Synechocystis and Cyanobium genera, from marine and freshwater origin, were highlighted as fast-growing (0.1-0.2 g L-1 day(-1)) with distinct biomass composition. Synechocystis sp. LEGE 07367 and Chroococcales cyanobacterium LEGE 19970, showed a production of 0.3 and 0.4 g L-1 of released polysaccharides (RPS). These were found to be glucan-based polymers with high molecular weight and a low number of monosaccharides than usually reported for cyanobacterial EPS. In addition, the absence of known cyanotoxins in these two RPS producers was also confirmed. This work provides the initial steps for the development of cyanobacterial EPS bioprocesses under the Portuguese climate.
- Biotecnologia Marinha – biocombustíveis, biorrefinaria e alimentos innovadoresPublication . Varela, João; Raposo, Sara; Pereira, Hugo; Barreira, LuísaApesar de fazer parte da estratégia de “blue growth” da União Europeia, a biotecnologia marinha ainda é uma atividade pouco explorada para desenvolver a economia local, nacional e transnacional ligada ao mar. No entanto, esta actividade de investigação tem a capacidade de gerar emprego altamente qualificado e com um potencial de inovação elevado. Através de uma colaboração entre dois grupos de investigação da Universidade do Algarve e companhias como a NECTON e SPAROS, estão-se a dar os primeiros passos para a implementação do conceito de biorrefinaria com vista ao aproveitamento integral e sustentável da biomassa de microalgas marinhas. Esse aproveitamento permitirá a produção de biocombustíveis na forma de biodiesel e bioetanol, a formulação de alimentos, rações e cosméticos inovadores e isolamento de compostos bioactivos com aplicação biomédica de alto valor acrescentado. Além disso, esforços de bioprospeção deram lugar ao isolamento de uma microalga susceptível de ser cultivada em efluentes de ETARs. O objectivo final será aliar a produção de biocombustíveis ao tratamento de águas, possibilitando assim uma fonte potencial de rendimento, que poderão aliviar os orçamentos municipais através de uma redução dos custos de operação.