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Microalgae are a sustainable source of nutraceuticals such as omega-3 fatty acids and carotenoid pigments. Therefore, nutraceutical profiling of microalgae is essential to identify high-yielding candidates for cultivation upscaling and commercialisation. The present study investigated the pigment and fatty acid profiles of 10 marine species within the chlorophyte genus Tetraselmis, with a quantitative focus on the high-value nutraceuticals lutein, β-carotene and the omega-3 fatty acid eicosapentaenoic acid (EPA, C20:5 ω3). To achieve this, fatty acid and pigment analyses were carried out via GC-MS and HPLC, respectively. When comparing the 10 Tetraselmis species, identical fatty acid and pigment compositions were observed. Palmitic acid (C16:0), α-linolenic acid (C18:3 ω3) and oleic acid (C18:1) were the primary constituents of the fatty acid profile for the Tetraselmis species. Furthermore, the pigment profile observed for each Tetraselmis species was typical of Chlorophyceae algae and included common green algal carotenoids such as lutein, violaxanthin and neoxanthin. Significant variations in the yields of high-value nutraceuticals were observed. For example, T. suecica (CCAP 66/38) returned the highest yield of EPA (3.10 ± 0.20 mg EPA g−1dw). Moreover, T. suecica (CCAP 66/38) was one of the more prominent Tetraselmis species in relation to β -carotene (7.17 mg β- Car g−1dw) and lutein (0.39 mg lut g−1dw) content. Thus, the present intragenus study documents species-specific responses to common growth conditions and variations in nutraceutical biosynthesis potential. Of note, T. suecica (CCAP 66/38), subject to further cultivation optimisation strategies, may represent a promising commercial source of the bioactive xanthophyll lutein, the provitamin A carotenoid β -carotene and the omega-3 fatty acid EPA. [Display omitted] • The pigment and fatty acid biosynthesis potential of 10 marine Tetraselmis species was investigated. • A common genus-unique pigment and fatty acid profile was observed with species-specific variations in the production of individual bioactive metabolites. • T. suecica (CCAP 66/38) returned the highest yield for EPA (3.10 ± 0.20 mg g−1dw). • T. chuii , T. gracilis and T. suecica were the most prominent species in relation to the synthesis of β -carotene and lutein. [ABSTRACT FROM AUTHOR]

The objective of this techno-economic analysis (TEA) was to define the production cost of the microalga Tetraselmis suecica in a 1-ha plant made of “Green Wall Panel-II” (GWP®-II) photobioreactors. The study was based on an energy analysis carried out for a similar plant located in Tuscany (Italy) and considers the steps from inoculum preparation to the wet algal paste. Costs of equipment and materials were obtained from manufacturers and suppliers, while operating costs and output data (e.g. biomass composition and productivity) were collected during several years of trials at the Fotosintetica & Microbiologica S.r.l. facilities (Florence, Italy). Other data were obtained from Microalghe Camporosso S.r.l. (Imperia, Italy), where a commercial 1500-m 2 GWP®-I plant is in operation and two 250-m 2 GWP®-II modules were built and used in the framework of the EU project BIOFAT. This TEA shows that, given a productivity of 36 tonnes per hectare per year, T. suecica biomass can be produced at a cost of €12.4 kg − 1 (dry weight). Using conservative assumptions it was estimated that at the 100-ha scale the cost will be €5.1 kg − 1 . Locating the plant in more favorable climatic conditions (e.g. in Tunisia) will allow reaching 54 tonnes per hectare annually and reducing cost to €6.2 kg − 1 at the 1-ha scale and to €3.2 kg − 1 at the 100-ha scale. The major cost factors are labor at 1-ha scale in Tuscany and capital expenses in all the other cases. This TEA confirms that microalgal technologies have high potential not only for high-value, but also for medium- and low-value products, while the production of biofuels, protein, food and feed seems currently out of reach. However, the global scenario of agriculture commodities is rapidly changing and other factors (e.g. sustainability), besides a pure economic evaluation, will assume greater importance in the future. [ABSTRACT FROM AUTHOR]

Abstract: Pharmaceuticals are continuously dispersed into the environment as a result of human and veterinary use, posing relevant environmental concerns. This study evaluated the acute toxicity of three therapeutic agents (diazepam, clofibrate, and clofibric acid) and a detergent (sodium dodecyl sulfate; SDS) in three aquatic species, namely the euryhaline fish Gambusia holbrooki, the hypersaline crustacean Artemia parthenogenetica, and the marine algae Tetraselmis chuii. The ranking of 50% lethal concentrations (LC50) for the two animal species and 50% inhibitory concentration (IC50) for the algal species was, in decreasing order, clofibric acid>SDS>diazepam>clofibrate for G. holbrooki, clofibric acid>clofibrate>SDS>diazepam for A. parthenogenetica, and clofibric acid>clofibrate>SDS>diazepam for T. chuii. These differences show that the intrinsic nature of test organisms must be considered when evaluating the toxicity of these agents to aquatic ecosystems. [Copyright &y& Elsevier]

Several species of the genus Tetraselmis (Chlorodendrophyceae, Chlorophyta) were recently discovered to possess unsuspected biomineralization capacities: they produce multiple intracellular inclusions of amorphous calcium carbonate (ACC), called micropearls. Early light-microscopists had spotted rows of refractive granules in some species, although without identifying their mineral nature. Scanning electron microscope (SEM) observations showed that the distribution of the micropearls in the cell forms a pattern, which appears to be characteristic for a given species. The present study shows that this pattern correlates with the shape of the chloroplast, which differs between Tetraselmis species, because micropearls align themselves along the incisions between chloroplast lobes. This was observed both by SEM and in live cells by light microscopy (LM) using Nomarski differential interference contrast. Additionally, molecular phylogenetic analyses, of rbcL and ITS2 gene sequences from diverse strains of Chlorodendrophyceae, corroborated the morphological observations by identifying two groups among nominal Tetraselmis spp. that differ in chloroplast morphology, micropearl arrangement, and ITS2 RNA secondary structure. [ABSTRACT FROM AUTHOR]