Microalgae for high-value products: A way towards green nutraceutical and pharmaceutical compounds.

Omics approaches for microalgal applications: Prospects and challenges.

Algae are considered pigment-producing organisms The function of these compounds in algae is to carry out photosynthesis They have a great variety of pigments, which can be classified into three large groups: chlorophylls, carotenoids, and phycobilins Within the carotenoids are xanthophylls Xanthophylls (fucoxanthin, astaxanthin, lutein, zeaxanthin, and β-cryptoxanthin) are a type of carotenoids with anti-tumor and anti-inflammatory activities, due to their chemical structure rich in double bonds that provides them with antioxidant properties In this context, xanthophylls can protect other molecules from oxidative stress by turning off singlet oxygen damage through various mechanisms Based on clinical studies, this review shows the available information concerning the bioactivity and biological effects of the main xanthophylls present in algae In addition, the algae with the highest production rate of the different compounds of interest were studied It was observed that fucoxanthin is obtained mainly from the brown seaweeds Laminaria japonica, Undaria pinnatifida, Hizikia fusiformis, Sargassum spp, and Fucus spp The main sources of astaxanthin are the microalgae Haematococcus pluvialis, Chlorella zofingiensis, and Chlorococcum sp Lutein and zeaxanthin are mainly found in algal species such as Scenedesmus spp, Chlorella spp, Rhodophyta spp, or Spirulina spp However, the extraction and purification processes of xanthophylls from algae need to be standardized to facilitate their commercialization Finally, we assessed factors that determine the bioavailability and bioaccesibility of these molecules We also suggested techniques that increase xanthophyll’s bioavailability

Xanthophylls from the Sea: Algae as Source of Bioactive Carotenoids.

In plant cells, ammonium is considered the most convenient nitrogen source for cell metabolism. However, despite ammonium being the preferred N form for microalgae, at higher concentrations, it can be toxic, and can cause growth inhibition. Microalgae’s tolerance to ammonium depends on the species, with various taxa showing different thresholds of tolerability and symptoms of toxicity. In the environment, ammonium at high concentrations represents a dangerous pollutant. It can affect water quality, causing numerous environmental problems, including eutrophication of downstream waters. For this reason, it is important to treat wastewater and remove nutrients before discharging it into rivers, lakes, or seas. A valid and sustainable alternative to conventional treatments could be provided by microalgae, coupling the nutrient removal from wastewater with the production of valuable biomass. This review is focused on ammonium and its importance in algal nutrition, but also on its problematic presence in aquatic systems such as wastewaters. The aim of this work is to provide recent information on the exploitation of microalgae in ammonium removal and the role of ammonium in microalgae metabolism.

https://www.mdpi.com/2071-1050/13/2/956/pdf

Ammonium Utilization in Microalgae: A Sustainable Method for Wastewater Treatment

N-3 polyunsaturated fatty acids (n-3 PUFAs), and especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential compounds for human health. They have been proven to act positively on a panel of diseases and have interesting anti-oxidative, anti-inflammatory or anti-cancer properties. For these reasons, they are receiving more and more attention in recent years, especially future food or feed development. EPA and DHA come mainly from marine sources like fish or seaweed. Unfortunately, due to global warming, these compounds are becoming scarce for humans because of overfishing and stock reduction. Although increasing in recent years, aquaculture appears insufficient to meet the increasing requirements of these healthy molecules for humans. One alternative resides in the cultivation of microalgae, the initial producers of EPA and DHA. They are also rich in biochemicals with interesting properties. After defining macro and microalgae, this review synthesizes the current knowledge on n-3 PUFAs regarding health benefits and the challenges surrounding their supply within the environmental context. Microalgae n-3 PUFA production is examined and its synthesis pathways are discussed. Finally, the use of EPA and DHA in food and feed is investigated. This work aims to define better the issues surrounding n-3 PUFA production and supply and the potential of microalgae as a sustainable source of compounds to enhance the food and feed of the future.

Microalgae n-3 PUFAs Production and Use in Food and Feed Industries.

Bioactive compounds, e.g., protein, polyunsaturated fatty acids, carotenoids, vitamins and minerals, found in commercial form of microalgal biomass (e.g., powder, flour, liquid, oil, tablet, or capsule forms) may play important roles in functional food (e.g., dairy products, desserts, pastas, oil-derivatives, or supplements) or feed (for cattle, poultry, shellfish, and fish) with favorable outcomes upon human health, including antioxidant, anti-inflammatory, antimicrobial, and antiviral effects, as well as prevention of gastric ulcers, constipation, anemia, diabetes, and hypertension. However, scale up remains a major challenge before commercial competitiveness is attained. Notwithstanding the odds, a few companies have already overcome market constraints, and are successfully selling extracts of microalgae as colorant, or supplement for food and feed industries. Strong scientific evidence of probiotic roles of microalgae in humans is still lacking, while scarce studies have concluded on probiotic activity in marine animals upon ingestion. Limitations in culture harvesting and shelf life extension have indeed constrained commercial viability. There are, however, scattered pieces of evidence that microalgae play prebiotic roles, owing to their richness in oligosaccharides—hardly fermented by other members of the intestinal microbiota, or digested throughout the gastrointestinal tract of humans/animals for that matter. However, consistent applications exist only in the dairy industry and aquaculture. Despite the underlying potential in formulation of functional food/feed, extensive research and development efforts are still required before microalgae at large become a commercial reality in food and feed formulation.

/pdf/potential-industrial-applications-and-commercialization-of-5dtp4478xn.pdf

Franciele Camacho

Papers

Potential Industrial Applications and Commercialization of Microalgae in the Functional Food and Feed Industries: A Short Review.