Algarve Centre for Marine Sciences

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Publications

Microalgal systems for wastewater treatment: technological trends and challenges towards waste recovery

Publication . Morais, Etiele G.; Cristofoli, Nathana L.; Maia, Inês B.; Magina, Tânia; Cerqueira, Paulo R.; Teixeira, Margarida Ribau; Varela, João; Barreira, Luísa; Gouveia, Luisa

ABSTRACT: Wastewater (WW) treatment using microalgae has become a growing trend due the economic and environmental benefits of the process. As microalgae need CO2, nitrogen, and phosphorus to grow, they remove these potential pollutants from wastewaters, making them able to replace energetically expensive treatment steps in conventional WW treatment. Unlike traditional sludge, biomass can be used to produce biofuels, biofertilizers, high value chemicals, and even next-generation growth media for “organically” grown microalgal biomass targeting zero-waste policies and contributing to a more sustainable circular bioeconomy. The main challenge in this technology is the techno-economic feasibility of the system. Alternatives such as the isolation of novel strains, the use of native consortia, and the design of new bioreactors have been studied to overcome this and aid the scale-up of microalgal systems. This review focuses on the treatment of urban, industrial, and agricultural wastewaters by microalgae and their ability to not only remove, but also promote the reuse, of those pollutants. Opportunities and future prospects are discussed, including the upgrading of the produced biomass into valuable compounds, mainly biofuels

2021-12Journal article

Open access

Heterotrophic and Photoautotrophic Media Optimization Using Response Surface Methodology for the Novel Microalga Chlorococcum amblystomatis

Publication . Correia, Nádia; Pereira, Hugo; Schulze, Peter; Costa, Monya M.; Santo, Gonçalo E.; Guerra, Inês; Trovão, Mafalda; Barros, Ana; Cardoso, Helena; Silva, Joana; Gouveia, Luisa; Varela, João

ABSTRACT: The nutritional requirements of novel microalgal strains are key for their effective cultivation and metabolite content. Therefore, the optimization of heterotrophic and photoautotrophic culture media is crucial for novel Chlorococcum amblystomatis growth. Heterotrophic and photoautotrophic biomass samples were characterized to identify the differences between their heterotrophic and photoautotrophic biomass composition and their biotechnological potential. Media optimization through surface response methodology led to 44.9 and 51.2% increments in C. amblystomatis-specific growth rates under heterotrophic and photoautotrophic growth, respectively. This microalga registered high protein content (61.49-73.45% dry weight), with the highest value being observed in the optimized photoautotrophic growth medium. The lipid fraction mainly constituted polyunsaturated fatty acids, ranging from 44.47 to 51.41% for total fatty acids (TFA) in cells under heterotrophy. However, these contents became significantly higher (70.46-72.82% TFA) in cultures cultivated under photoautotrophy. An interesting carotenoids content was achieved in the cultures grown in optimized photoautotrophic medium: 5.84 mg center dot g(-1) beta-carotene, 5.27 mg center dot g(-1) lutein, 3.66 mg center dot g(-1) neoxanthin, and 0.75 mg center dot g(-1) violaxanthin. Therefore, C. amblystomatis demonstrated an interesting growth performance and nutritional profile for food supplements and feed products that might contribute to meeting the world's nutritional demand.

2023-02Journal article

Open access

Sea surface temperature variations revealed by planktonic foraminifera at the Portuguese margin during the Holocene

Publication . Mega, Aline; Salgueiro, Emilia; Rebotim, Andreia; Voelker, Antje; Cruz, Joana; Calvo, Eva; Abrantes, Fatima

ABSTRACT: Global warming, resulting from increasing human emissions of greenhouse gases, is raising ocean temperatures, projecting an increase of 2.6 °C by the end of this century. With the aim of refining climate models and predicting future regional climate conditions more accurately, this study reconstructs sea surface water temperature during the current interglacial period, the Holocene, off the southwest coast of Portugal, through the analysis of associations of planktonic foraminifera. During this period, surface waters in the region south of Sines exhibited higher and more stable temperatures compared to those detected further north, in the Estremadura spur. The northern region, due to its geographical position, more prominently highlights short-duration cold events associated with polar ice melting and marine circulation.

2025-04Journal article

Open access