Green microalgae biomolecule separations and recovery

Abstract

Microalgae biomass has garnered significant attention as a renewable energy feedstock and alternative to petroleumbased fuels. The diverse metabolism of green microalgae species additionally provides opportunities for recovery of products for feed, food, nutraceutical, cosmetic, and biopharmaceutical industries. Recently, the concept of using microalgae as part of a biorefinery model has been adopted in place of refinery methods focused on recovering one target product. This has led to producers exploring co-production of high value and high volume products in an effort to improve process economics. With numerous potential products and applications, the biomass source or specific strain must be carefully selected to accumulate extractable levels of the target molecule(s). It is additionally imperative to understand the morphology and metabolism of the selected strain to cost-effectively manage all stages of commercial production. This review will focus specifically on microalgae in the division of Chlorophyta, or green algae and their extracellular matrices (ECM), potential for commercial products, and finally describe a holistic approach for biomolecule extraction and recovery. Additionally, cell disruption and fractionation methods for recovery of biomolecules for commercial products are highlighted along with an alternative method, aqueous enzymatic processing for multiple biomolecule extraction and recovery from green microalgae. An emphasis is placed on connecting the morphological characteristics of microalgae ECM or organelle membranes to implications on separation and purification technologies.

Enigmatic Microalgae from Aeroterrestrial and Extreme Habitats in Cosmetics: The Potential of the Untapped Natural Sources

“…Carotenoids such as astaxanthin, β-carotene, and lutein can be included as part of topical cosmetic products for protection against UV-induced damage [18,20,24]. Specifically, β-carotene is used in the formulation of skin care products [21,41].…”

“…Among them, astaxanthin also presents interesting depigmentation properties which provide a protection for skin from age spots by reducing melanin production by 40% and improving all skin layers [191][192][193]. Therefore, astaxanthin, can be included as part of topical cosmetic products for protection against hyper-pigmentation, and the same is valid for β-carotene and lutein [18,20,24,193]. Fucoxanthin can also help to reduce the activity of tyrosinase and melanogenesis [193,194].…”

“…Among such active ingredients extracted from microalgae are polysaccharides which, just as those from macroalgae, are used as gelling agents and thickeners in different cosmetic formulas, as well as for moisturizing [18,204]. Similarly, polysaccharides from various green microalgae species can be included in cosmetic products for the purposes of antioxidant activity, gelling or thickening [18,24].…”

Membrane‐assisted biorefinery of microalgae to obtain enriched fractions of bioderived molecules

“…Studies reported in the literature demonstrated that the most critical steps to recover internally stored biomolecules are cell disruption and fractionation of bioderived products by a clean technology …”

“…However, within a ‘circular economy’ strategy, the valorization of the main high added‐value compounds by the use of green solvents and green technologies is sought. The general consensus is that the high value of different final products has the potential to increase the total value of microalgae biomass . For these reasons, the aim of this work is to study an alternative approach to valorize the main constituents of the microalgal biomass, fractionating hydrophobic from hydrophilic compounds with a tuned sustainable biorefinery strategy.…”