Microalgae As a Green source for Nutritional Ingredients for Food/Feed and Ingredients for Cosmetics by cost-Effective New Technologies

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Immune status and hepatic antioxidant capacity of Gilthead Seabream Sparus aurata juveniles fed yeast and microalga derived β-glucans

Publication . Reis, Bruno; Gonçalves, Ana Teresa; Santos, Paulo; Sardinha, Manuel; Conceição, Luís E. C.; Serradeiro, Renata; Pérez-Sánchez, Jaume; Calduch-Giner, Josep; Schmid-Staiger, Ulrike; Frick, Konstantin; Dias, Jorge; Costas, Benjamín

This work aimed to evaluate the effects of dietary supplementation with β-glucans extracted from yeast (Saccharomyces cerevisiae) and microalga (Phaeodactylum tricornutum) on gene expression, oxidative stress biomarkers and plasma immune parameters in gilthead seabream (Sparus aurata) juveniles. A practical commercial diet was used as the control (CTRL), and three others based on CTRL were further supplemented with different β-glucan extracts. One was derived from S. cerevisiae (diet MG) and two different extracts of 21% and 37% P. tricornutum-derived β-glucans (defined as Phaeo21 and Phaeo37), to give a final 0.06% β-glucan dietary concentration. Quadruplicate groups of 95 gilthead seabream (initial body weight: 4.1 ± 0.1 g) were fed to satiation three times a day for 8 weeks in a pulse-feeding regimen, with experimental diets intercalated with the CTRL dietary treatment every 2 weeks. After 8 weeks of feeding, all groups showed equal growth performance and no changes were found in plasma innate immune status. Nonetheless, fish groups fed β-glucans supplemented diets showed an improved anti-oxidant status compared to those fed CTRL at both sampling points (i.e., 2 and 8 weeks). The intestinal gene expression analysis highlighted the immunomodulatory role of Phaeo37 diet after 8 weeks, inducing an immune tolerance effect in gilthead seabream intestine, and a general down-regulation of immune-related gene expression. In conclusion, the results suggest that the dietary pulse administration of a P. tricornutum 37% enriched-β-glucans extract might be used as a counter-measure in a context of gut inflammation, due to its immune-tolerant and anti-oxidative effects.

2021-12Journal article

Open access

Fucoxanthin production from Tisochrysis lutea and Phaeodactylum tricornutum at industrial scale

Publication . Pereira, Hugo; Sá, Marta; Maia, Inês Beatriz; Rodrigues, Alexandre; Teles, Iago; Wijffels, Rene H.; Navalho, João; Barbosa, Maria

Fucoxanthin is a xanthophyll carotenoid with high market value. Currently, seaweeds are the primary source for fucoxanthin industrial production. However, marine microalgae reach 5 to 10 times higher concentrations (2.24 to 26.6 mg g-1 DW) and are considered a promising feedstock. In this work, two marine microalgae were produced at industrial scale to evaluate biomass and fucoxanthin production: Phaeodactylum tricornutum for autumn/winter and Tisochrysis lutea for spring/summer. Both strains were grown in 15 m3 tubular flow-through photobioreactors; for 170 consecutive days of semi-continuous cultivation regime. The average volumetric biomass productivities of P. tricornutum and T. lutea were 0.11 and 0.09 g DW L-1 day-1. P. tricornutum reached higher maximum biomass concentration (2.87 g DW L-1) than T. lutea (1.47 g DW L-1). P. tricornutum fucoxanthin content ranged between 0.2 and 0.7% DW, while T. lutea between 0.2 and 0.6% DW. The fucoxanthin content was correlated with the irradiation (MJ m-2) and biomass concentration in the photobioreactor (g L-1). This is the first work in literature reporting a long-term industrial production of T. lutea. Overall, we showed possible scenarios for fucoxanthin production from microalgae, increasing the window to supply the industry with steady production throughout the year.

2021-06Journal article

Open access

Techno-economic assessment of microalgae production, harvesting and drying for food, feed, cosmetics, and agriculture

Publication . Vázquez-Romero, Bárbara; Perales, José Antonio; Pereira, Hugo; Barbosa, Maria; Ruiz, Jesús

The objective of this techno-economic analysis is to define the costs for an industrial microalgae production process, comparing different operation strategies (Nannochloropsis oceanica cultivation during the whole year or cultivation of two species, where Phaeodactylum tricornutum and Tisochrysis lutea alternate), production scales (1 and 10 ha), har -vesting technologies (centrifugation or ultrafiltration) and drying methods (freeze-drying or spray drying). This study is based on an industrial scale process established in the south of Portugal. The strategy of cultivating N. oceanica all year round is more attractive from an economic perspective, with production costs of 53.32 euro/kg DW anda productiv-ity of 27.61 t/y for a scale of 1 ha, a 49.31% lower cost and two-fold productivity than species alternation culture strat-egy. These results are for biomass harvested by centrifugation (10.65% biomass cost) and freeze-drying (20.15% biomass cost). These costs could be reduced by 7.03% using a combination of ultrafiltration and spray drying, up to 17.99% if expanded to 10 ha and 10.92% if fertilisers were used instead of commercial nutrient solutions. The study shows potentially competitive costs for functional foods, food, and feed additives, specialised aquaculture prod-ucts (live feed enrichment) and other high value applications (e.g., cosmetics).

2022Journal article

Open access