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Senegalese sole (Solea senegalensis) production presents several nutritional challenges, making this species a good candidate to study the dietary potential of bioactive compounds. Since proper nutrition plays a fundamental role in fish biology, it is necessary to further investigate species-specific and well-balanced diets in order to improve Senegalese sole juvenile farming. Algae have antioxidant properties, high-quality dietary protein, and are a source of bioactive compounds. This study evaluates the effects of dietary microalgal inclusion in both health status and growth performance of Senegalese sole post-larvae. Individuals 41 days after hatching (DAH) were randomly distributed among 12 tanks and four experimental diets were randomly distributed by triplicate groups. A basal diet served as CTRL and the experimental diets were formulated to include 3% of each of the algal biomass (CHLO, Chlorella sp. from heterotrophic production; PHAEO, Phaeodactylum sp.; and NANNO, Nannochloropsis sp.). At 50 DAH, 20 post-larvae/tank were collected and homogenized for analysis of immune and oxidative status, and at 61 DAH the total length, dry weight, and survival were assessed. No changes were observed in survival and total length of individuals, post-larvae fed NANNO, and CHLO dietary treatments increased dry weight at 61 DAH compared with those fed CTRL. While post-larvae immune status was apparently not altered by dietary treatments at 50 DAH, the total glutathione content decreased in fish fed PHAEO and CHLO dietary treatments compared to control diet. The observed results on improvement of growth performance without adverse effects on the immune status and decrease of endogenous total glutathione point to the fact that Nannochloropsis sp., Phaeodactylum sp., and Chlorella sp. could work as potential candidates for inclusion in microdiets for Senegalese sole. VALORMAR project - Compete 2020 [POCI-01-0247-FEDER-024517]; Lisboa 2020; CRESC Algarve 2020; Portugal 2020; European Union through European Regional Development Fund; Foundation for Science and Technology (FCT)Portuguese Foundation for Science and TechnologyEuropean Commission [UIDB/04423/2020, UIDP/04423/2020]; FCT, PortugalPortuguese Foundation for Science and TechnologyEuropean Commission [SFRH/BD/108243/2015, PD/BDE/129262/2017, IF/00197/2015] info:eu-repo/semantics/publishedVersion

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. info:eu-repo/semantics/publishedVersion

Large-scale cultivation of Chlorella vulgaris is of great interest given the extent of products and potential applications that can derive from its biomass. From an industrial point of view it is imperative to consistently obtain high productivities and high quality biomass at the lowest production costs. The mass balance of critical nutrients such as carbon and nitrogen is therefore necessary to quantify its recovery and consumption yields, the efficiency of the biomass production system and to identify operational optimization opportunities. The mass balance of C. vulgaris mixotrophic growth throughout scale-up from 10 m 3 to 100 m 3 on acetate and urea as carbon and nitrogen sources was calculated using a black-box model developed to illustrate the inputs and outputs of the system in quasi - real time and resulted on recovery factors of 0.99 ± 0.08 and 0.99 ± 0.25, respectively. Under these conditions C. vulgaris cultivation yielded a maximal productivity of 0.14 g L − 1 d − 1 and maximal growth rate of 0.38 d − 1 . Both parameters decreased throughout scale up reaching an average productivity of 0.09 g L − 1 d − 1 with an average growth rate of 0.13 d − 1 for the whole process. Global carbon and nitrogen yields measured were 0.76 mol C-X mol C − 1 and 0.72 mol N-X mol N − 1 . The mass balance determination indicates the incorporation of both acetate and urea carbon atoms into the biomass. Therefore, external inorganic carbon from CO 2 was concluded to have little influence on microalgae growth in the conditions studied apart from pH control. Urea and ammonium were found to be effectively used by C. vulgaris cells. However, despite the satisfactory yield obtained for nitrogen, the metabolism of urea resulted in ammonium build-up in the culture medium. To our knowledge this is the first report of growth parameters and mass balance analysis of a Chlorella sp. culture in industrial scale closed tubular photobioreactors.

ALGAFARM is an industrial-scale microalgae production facility for the production of Chlorella biomass for food and feed applications. ALGAFARM integrates the entire production process, from small-volume production at a lab scale to final product packaging. It uses a combination of closed photobioreactor (PBR) technologies comprising mainly of large modular arrays of tubular PBRs (Figure 13.1) to cultivate the microalgae. The closed modular PBRs are based on transparent plastic