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The long-lasting interest in bioactive molecules (namely toxins) produced by (microalga) dinoflagellates has risen in recent years. Exhibiting wide diversity and complexity, said compounds are well-recognized for their biological features, with great potential for use as pharmaceutical therapies and biological research probes. Unfortunately, provision of those compounds is still far from sufficient, especially in view of an increasing demand for preclinical testing. Despite the difficulties to establish dinoflagellate cultures and obtain reasonable productivities of such compounds, intensive research has permitted a number of advances in the field. This paper accordingly reviews the characteristics of some of the most important biotoxins (and other bioactive substances) produced by dinoflagellates. It also presents and discusses (to some length) the main advances pertaining to dinoflagellate production, from bench to large scale—with an emphasis on material published since the latest review available on the subject. Such advances encompass improvements in nutrient formulation and light supply as major operational conditions; they have permitted adaptation of classical designs, and aided the development of novel configurations for dinoflagellate growth—even though shearing-related issues remain a major challenge. © 2017 by the authors.

The current mindset in the cosmetics market about sustainable ingredients had increased the search for new sources of natural active ingredients. Cyanobacteria are a great source of functional ingredients for cosmetics, as a producer of pigments with described bioactive potential (carotenoids and phycobiliproteins). This work aimed to evaluate the cosmetic potential of marine cyanobacterium Cyanobium sp. pigment-targeted extracts (carotenoids and phycobiliproteins), evaluating their in vitro safety through cytotoxicity assays, cosmetic-related enzyme inhibition, ingredient stability, and putative product (serum formulation). Results showed no cytotoxicity from the extracts in skin-related cell lines. Carotenoid extract showed anti-hyaluronidase capacity (IC50 = 108.74 ± 5.74 mg mL−1) and phycobiliprotein extract showed anti-hyaluronidase and anti-collagenase capacity (IC50 = 67.25 ± 1.18 and 582.82 ± 56.99 mg mL−1, respectively). Regarding ingredient and serum stability, both ingredients showed higher stability at low-temperature conditions, and it was possible to maintain the pigment content and bioactive capacity stable during the tested period, although in higher temperatures the product was degraded in a week. As a major conclusion, both extracts can be potential natural and sustainable ingredients for cosmetic uses, with relatively simple formulation and storage, and can be promising natural anti-aging ingredients due to their bioactive capacity.

Pigments from microalgae and cyanobacteria have attracted great interest for industrial applications due to their bioactive potential and their natural product attributes. These pigments are usually sold as extracts, to overcome purification costs. The extraction of these compounds is based on cell disruption methodologies and chemical solubility of compounds. Different cell disruption methodologies have been used for pigment extraction, such as sonication, homogenization, high-pressure, CO2 supercritical fluid extraction, enzymatic extraction, and some other promising extraction methodologies such as ohmic heating and electric pulse technologies. The biggest constrain on pigment bioprocessing comes from the installation and operation costs; thus, fundamental and applied research are still needed to overcome such constrains and give the microalgae and cyanobacteria industry an opportunity in the world market. In this review, the main extraction methodologies will be discussed, taking into account the advantages and disadvantages for each kind of pigment, type of organism, cost, and final market.

Sea urchin processing practices by the canning industry result in a large volume of waste due to a high fraction of inedible parts, in special the gut, that can still be a valuable source of bioactive compounds. Therefore, this work aimed to thoroughly characterise gut biomass from Paracentrotus lividus evaluating its bioactive potential. The gut biomass was evaluated in terms of bioactive capacity, and biochemical composition in both males and females. Although no statistical differences were found between sexes in any of these parameters, this study provided a proof of concept on the potential of sea urchin's gut, obtained as a co-product in the sea urchin industry, for feed supplementation. The gut biomass exhibited a high antioxidant capacity (IC 50 ≈ 0.5–1.0 mg DW mL −1 in four different assays) and bactericidal activity (IC 50 < 1.0 mg DW mL −1 against Vibrio parahaemolyticus , Edwardsiella tarda , and Tenacibaculum maritimum ). The gut co-product can also be used as a source of phenolic compounds, carotenoids, and PUFAs, with contents of 4.6 ± 0.4, 2.4 ± 0.8, and 93.0 ± 3.1 mg g DW −1 , respectively. Overall, the sea urchin's gut seems a valuable product with a remarkable potential for use in aquafeeds as a source of bioactive compounds.

Microalgae are well known for their biotechnological potential, namely with regard to bioactive lipidic components—especially carotenoids and polyunsaturated fatty acids (PUFA), well-known for therapeutic applications based on their antioxidant capacity. The aim of this work was to evaluate the influence of four distinct food-grade solvents upon extractability of specific lipidic components, and on the antioxidant capacity exhibited against both synthetic (2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+•)) and biological reactive species (O2•- and •NO-). A eukaryotic microalga (Scenedesmus obliquus (M2-1)) and a prokaryotic one (Gloeothece sp.) were used as case studies. Concerning total antioxidant capacity, the hexane:isopropanol (3:2) and acetone extracts of Sc. obliquus (M2-1) were the most effective against DPPH• and ABTS+•, respectively. Gloeothece sp. ethanol extracts were the most interesting scavengers of O2•-, probably due the high content of linolenic acid. On the other hand, acetone and hexane:isopropanol (3:2) extracts were the most interesting ones in •NO- assay. Acetone extract exhibited the best results for the ABTS assay, likely associated to its content of carotenoids, in both microalgae. Otherwise, ethanol stood out in PUFA extraction. Therefore, profiles of lipidic components extracted are critical for evaluating the antioxidant performance—which appears to hinge, in particular, on the balance between carotenoids and PUFAs.

The nutraceutical potential of microalgae boomed with the exploitation of new species and sustainable extraction systems of bioactive compounds. Thus, a laboratory-made continuous pressurized solvent extraction system (CPSE) was built to optimize the extraction of antioxidant compounds, such as carotenoids and PUFA, from a scarcely studied prokaryotic microalga, Gloeothece sp. Following \"green chemical principles\" and using a GRAS solvent (ethanol), biomass amount, solvent flow-rate/pressure, temperature and solvent volume-including solvent recirculation-were sequentially optimized, with the carotenoids and PUFA content and antioxidant capacity being the objective functions. Gloeothece sp. bioactive compounds were best extracted at 60?C and 180 bar. Recirculation of solvent in several cycles (C) led to an 11-fold extraction increase of ß-carotene (3C) and 7.4-fold extraction of C18:2 n6 t (5C) when compared to operation in open systems. To fully validate results CPSE, this system was compared to a conventional extraction method, ultrasound assisted extraction (UAE). CPSE proved superior in extraction yield, increasing total carotenoids extraction up 3-fold and total PUFA extraction by ca. 1.5-fold, with particular extraction increase of 18:3 n3 by 9.6-fold. Thus, CPSE proved to be an efficient and greener extraction method to obtain bioactive extract from Gloeothece sp. for nutraceutical purposes-with low levels of resources spent, while lowering costs of production and environmental impacts. © 2018 by the authors.

► Helicobacter pylori is labeled as the primary cause of gastric cancer. ► Microalgal sulfated polysaccharides block adhesion of H. pylori to stomach mucosa. ► Microalgal astaxanthin also possesses immunomodulatory action upon infection by H. pylori. ► Microalgal carotenoids and PUFA possess anticancer features. Gastrointestinal cancers rank second in overall cancer-related deaths. Carotenoids, sulfated polysaccharides, and polyunsaturated fatty acids (PUFAs) from microalgae exhibit cancer chemopreventive features at different stages of carcinogenesis. For instance, sulfated polysaccharides bear a prophylactic potential via blocking adhesion of pathogens to the gastric surface, whereas carotenoids are effective against Helicobacter pylori infection. This effect is notable because H. pylori has been targeted as the primary cause of gastric cancer. Recent results on antitumor and antibacterial compounds synthesized by microalgae are reviewed here, with an emphasis on their impact upon H. pylori infection and derived pathologies accompanying the progression of gastric carcinogenesis.

Cyanobacteria-based pigments, such as carotenoids and phycobiliproteins, have emerged in the last few years as products with great economical interest. However, only the production of a few strains has been optimized for large-scale productions. As photosynthetic components, pigments have their synthesis modulated by abiotic factors, such as pH, temperature and salinity, which can lead to a huge impact on cyanobacteria production. This work aimed the optimization of biomass and pigments production by Cyanobium sp. LEGE 06113, using a factorial Box-Behnken design for three abiotic factors—temperature (20–30 °C), pH (6.0–9.0) and salinity (NaCl, 10–30 g L−1). Biomass, photosynthetic activity, carotenoid and phycobiliprotein productivity and antioxidant capacity of acetonic and aqueous extracts were measured over time and plotted into quadratic models. Results revealed that temperature and pH had a more significant impact than salinity on Cyanobium sp. metabolism and it was possible to determine a significant quadratic model for all evaluated parameters. According to the factorial modelling, the optimal condition for biomass, carotenoids and phycobiliprotein productivity was obtained at 20 °C, pH 9.0 and 10 g L−1 of NaCl, as subsequently confirmed in experimental trials, with an observed productivity of 127.12 ± 1.30 mgDW Lculture−1 day−1 for biomass; 2.04 ± 0.51 mgcarot Lculture−1 day−1 for total carotenoids; and 4.14 ± 0.71 mgphyco Lculture−1 day−1 for total phycobiliproteins.

A cyanobacterium of the genus Chroococcidiopsis has been recently unveiled to go to Mars, owing to its unique ability to stand harsh environmental conditions. Nevertheless, it has been little characterized in terms of other biotechnological applications. The aim of this study was thus to explore the biotechnological potential of Chroococcidiopsis sp. LEGE 06174, using GRAS (generally recognized as safe) solvents for the combined extraction of bioactive compounds. Due to its mucilaginous sheath, sulfuric acid, NaOH, PBS, DMSO 20%, DMSO 100%, and acetone were tested as preliminary treatment—in attempts to enhance pigment extraction. Extracts were then obtained by several series of successive extractions: phosphate-buffered saline (PBS) (serie A), ethanol-PBS (serie B), acetone-PBS (serie C), methanol-PBS (serie D), and acetone-methanol-PBS (serie E). Such extracts were screened for antioxidant capacity, cytotoxicity, and physicochemical characterization in terms of polysaccharides, pigments, and total phenolic compounds. Pre-treatment with PBS proved the most effective toward overall pigment extraction and dissolution of the said mucilaginous sheath. Chroococcidiopsis sp. extracts have unfolded some interesting bioactive features, particularly upon pre-treatment with PBS—i.e., high antioxidant capacity and high content in polysaccharides, scytonemin, phycobiliproteins, and phenolic compounds. The highest total pigment content was obtained in serie D, particularly carotenoids, whereas the highest level of phenolic compounds was found in serie B. All in all, Chroococcidiopsis sp. appears to constitute a significant biotechnological resource worthy of further exploitation in terms of high added-value compounds.

Microalgae are known producers of antioxidant and anti-inflammatory compounds, making them natural alternatives to be used as food and feed functional ingredients. This study aimed to valorise biomass and exploit new applications and commercial value for four commercially available microalgae: Isochrysis galbana, Nannochloropsis sp., Tetraselmis sp., and Phaeodactylum tricornutum. For that, five extracts were obtained: acetone (A), ethanol (E), water (W), ethanol:water (EW). The antioxidant capacity (ABTS•+/DPPH•/•NO/O2•−/ORAC-FL) and anti-inflammatory capacity (HBRC/COX-2) of the extracts were screened. The general biochemical composition (carbohydrates, soluble proteins, and lipids) and the main groups of bioactive compounds (carotenoids, phenolic compounds, and peptides) of extracts were quantified. The results of antioxidant assays revealed the potential of some microalgae extracts: in ABTS•+, Nannochloropsis sp. E and Tetraselmis sp. A, E, and P; in DPPH•, Tetraselmis sp. A and E; in •NO, P. tricornutum E and EW; in O2•−, Tetraselmis sp. W; and in ORAC-FL, I. galbana EW and P. tricornutum EW. Concerning anti-inflammatory capacity, P. tricornutum EW and Tetraselmis sp. W showed a promising HBRC protective effect and COX-2 inhibition. Hence, Tetraselmis sp. and P. tricornutum extracts seem to have potential to be incorporated as feed and food functional ingredients and preservatives.