Microalgae Biomolecules: Extraction, Separation and Purification Methods

Abstract

Several microalgae species have been exploited due to their great biotechnological potential for the production of a range of biomolecules that can be applied in a large variety of industrial sectors. However, the major challenge of biotechnological processes is to make them economically viable, through the production of commercially valuable compounds. Most of these compounds are accumulated inside the cells, requiring efficient technologies for their extraction, recovery and purification. Recent improvements approaching physicochemical treatments (e.g., supercritical fluid extraction, ultrasound-assisted extraction, pulsed electric fields, among others) and processes without solvents are seeking to establish sustainable and scalable technologies to obtain target products from microalgae with high efficiency and purity. This article reviews the currently available approaches reported in literature, highlighting some examples covering recent granted patents for the microalgae’s components extraction, recovery and purification, at small and large scales, in accordance with the worldwide trend of transition to bio-based products.

Microalgae Polysaccharides: An Overview of Production, Characterization, and Potential Applications

“…Ion exchange chromatography uses the difference between the charge properties of molecules to promote separation. By manipulating the pH, it is possible to change the net surface charge of charged biomolecules to achieve higher selectivity [48]. Size exclusion chromatography can be used to separate microalgal polysaccharides with different molecular weights or molecular sizes [49].…”

“…Gel permeation chromatography is a widely used size exclusion chromatography for separating macromolecules. For microalgae, this technique has been applied to characterize polysaccharides [48]. In affinity chromatography, the target molecule charged by the mobile phase binds to the immobilized ligand on the stationary phase by affinity.…”

Development of 2,3-Butanediol Production Process from Klebsiella aerogenes ATCC 29007 Using Extracted Sugars of Chlorella pyrenoidosa and Biodiesel-Derived Crude Glycerol

“…The components of C. pyrenoidosa were analyzed to be 9.94% carbohydrate (55% glucose and 45% galactose), 0.64% fiber, 56.61% protein, 4.55% lipid, and 7.86% ash [15]. The sugar extraction process was performed with 2% hydrochloric acid and a solid-liquid ratio of 100 g/L in an Erlenmeyer flask, using an autoclave (VS-1221-100, Vision science, Daejeon, South Korea) at 121 • C for 15 min, after which the pH was regulated to 7 by using NaOH [12].…”

“…Presently, algae-sea plants-are being focused on as the next generation carbon source. Because sea algae also photosynthesize, they have all the merits of land plants [12]. Additionally, it is well known that they grow rapidly because they have higher photosynthesis efficiency than land plants, and they have a 1.5-fold to 2-fold higher carbon dioxide fixation effect [13,14].…”

“…Chlorella, a microalgae species, is a round algae living in seawater and freshwater, looks similar to Nannochloropsis, and is currently used for production of biodiesel due to its high lipid content. However, other than lipids, it also contains sugars that can be fermented, and the contained sugars can be extracted along with lipids [12][13][14][15][16]. These sugars can be used as the carbon source and converted to biofuels and chemical substances.…”