Fatty acids of microalgae: diversity and applications

Abstract

The possibility of obtaining commercially valuable products from microalgae stimulates scientific research in this direction. The ability of microalgae to accumulate lipids is very promising from the point of view of practical application. The diversity of the composition of microalgae lipids makes it possible to study a wide range of their applications: biofuel production, food products, feed for farm animals and birds, for aquaculture, food additives, etc. Fatty acids (FAs) are involved in the metabolic pathways of formation and conversion of most lipid classes, and their composition largely determines their properties and practical use. As a result, much attention is paid to the study of the composition of fatty acids in microalgae (including cyanobacteria). This review summarizes information on the diversity of the fatty acid composition of microalgae and cyanobacteria, taking into account their rare and unusual categories. The total variety of FA profile of microalgae from different habitats is formed by 135 FAs. Taking into account the length of the hydrocarbon chain, its structure and the presence of substituents, they are distributed into several groups: with an even number of carbon atoms in the chain—81 (short-chain FAs—2, medium-chain FAs—14, long-chain FAs—28, very-long-chain FAs—37), with an odd number of carbon atoms—33, with a branched hydrocarbon chain and additional functional groups—21. Among FAs of microalgae there are both saturated and unsaturated FAs with different numbers of double bonds: saturated FAs—19, monounsaturated FAs—26, polyunsaturated FAs—68. The FA profile of microalgae is rich in omega-3 and omega-6 fatty acids. The review also considers the use of fatty acids as an industrial resource, as well as a biomarker.