Access to vital raw ingredients for food/feed production is an increasing challenge in several industries. Microalgae are sunlight-driven cell factories that are able to efficiently utilize carbon dioxide for the production of numerous products such as proteins, polysaccharides, oils, vitamins, carotenoids and other biologically active compounds, and are therefore used in a wide variety of technological applications for the development of feed and food products. Of the carotenoids, astaxanthin, a red ketocarotenoid, possesses a wide range of applications in feed, food, nutraceutical, and pharmaceutical industries because of its strong pigmentation function, powerful antioxidative activity and broad beneficial effects on human health. ACCORDION is a proven and efficient platform for industrial scale production of high quality microalgae, at lower energy and decreased production cost, compared to other solutions. This technology aims to strengthen Europe’s position in the microalgae market, which is currently weak due to cheaper, low quality foreign competitors. Accordion bioreactor is made of a flexible plastic sheeting wrapped around steel bars, forming different chambers for holding fluid. The entire structure is aligned on a vertical axis and chambers are oriented at an adjustable angle depending on the bars’ distance. This peculiar configuration improves light incidence on the chambers, liquid mixing and bubble breakup. The bioreactor also includes tools for inserting fluid (a nutrient solution and/or a suspension of cells) and at least one delivery device for providing carbon dioxide, air and other needed gases to the culture. The system is essentially closed except for at least one opening (for example an opening at the bottom edge) that allows for the introduction of gases and/or nutrients. The gas and/or nutrients are introduced in such a way as to create a flow pattern driven by the rising bubbles, securing enough circulation without a pump. The Accordion bioreactor is applicable for photoautotrophic, mixotrophic and heterotrophic microalgae production. Accordion aims at producing naturally sourced astaxanthin from Haematococcus pluvialis or C. zofingiensis, grown using the nutrients from fish sludge.
