From Current Algae Products to Future Biorefinery Practices: A Review

Abstract

Microalgae are considered to be one of the most promising next generation bio-based/food feedstocks with a unique lipid composition, high protein content, and an almost unlimited amount of other bio-active molecules. High-value components such as the soluble proteins, (poly) unsaturated fatty acids, pigments, and carbohydrates can be used as an important ingredient for several markets, such as the food/feed/chemical/cosmetics and health industries. Although cultivation costs have decreased significantly in the last few decades, large microalgae production processes become economically viable if all complex compounds are optimally valorized in their functional state. To isolate these functional compounds from the biomass, cost-effective, mild, and energy-efficient biorefinery techniques need to be developed and applied. In this review we describe current microalgae biorefinery strategies and the derived products, followed by new technological developments and an outlook toward future products and the biorefinery philosophy.

Selective and mild fractionation of microalgal proteins and pigments using aqueous two‐phase systems

“…Microalgae are a promising feedstock for many industries including biopharmaceuticals, biomaterials, bioenergy, nutraceuticals, agriculture, animal health and cosmetics and personal care . Feasibility studies demonstrate that a biorefinery focus on one single product is not cost‐efficient and that several microalgal components should be extracted to supply different markets, and thus increase the overall value of microalgal biomass …”

“…1 Feasibility studies demonstrate that a biorefinery focus on one single product is not cost-efficient 2 and that several microalgal components should be extracted to supply different markets, and thus increase the overall value of microalgal biomass. 3 Depending on the strain, microalgae can contain chlorophylls (green), carotenoids (red, orange and yellow) and phycobiliproteins (red and blue). 4,5 Neochloris oleoabundans accumulates mainly lutein, cantaxanthin, zeaxanthin, and astaxanthin monoesters and diesters, which are promising ingredients for pharmaceutical and nutraceutical applications.…”

Techno‐economic comparative assessment of novel lignin depolymerization routes to bio‐based aromatics

“…There is also ongoing research on third‐generation biomass – i.e. macro‐ and micro‐algae . Lignocellulosic biomass refers to inedible plant material mainly composed of cellulose, hemicellulose, and lignin.…”

Biorefinery of functional biomolecules from algae

“…Biorefinery is defined as "the sustainable processing of biomass into a spectrum of marketable products and energy" (Trivedi et al, 2015). Eppink et al, (2017) proposed that an algal biorefinery is similar to a modern dairy plant in which a mixture of proteins, carbohydrates and fat are processed and fractionated. However, due to the complex cell structure, the biorefinery of algae requires additional unit operations for harvesting and cell disintegration.…”

“…The next step after/during cell disintegration is extraction, for which several technologies have been investigated (Eppink et al, 2017)(Vanthoor-koopmans et al, 2012. Most reported investigations make use of an aqueous buffer in which watersoluble molecules are extracted (Safi et al, 2014a).…”