Fatty acid composition of several wild microalgae and cyanobacteria, with a focus on eicosapentaenoic, docosahexaenoic and α-linolenic acids for eventual dietary uses

Abstract

A total of 13 species of microalgae and 14 strains of cyanobacteria, collected directly in the Portuguese coast and lagoons, were characterized for their fatty acid contents, focusing on two with a market potential — i.e. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); and another already with alternative (yet somehow more expensive) natural sources — i.e. α-linolenic (ALA) acid. The purpose of this work was their eventual inclusion as additives in food or feed. ALA was the most abundant PUFA in Nannochloropsis sp. (0.616 ± 0.081 mg FA.L culture − 1 .d − 1 ), and EPA in Phaeodactylum tricornutum (0.148 ± 0.013 mg FA.L culture − 1 .d − 1 ); Pavlova lutheri was particularly rich in EPA (0.290 ± 0.005 mg FA.L culture − 1 .d − 1 ) and DHA (0.140 ± 0.037 mg FA.L culture − 1 .d − 1 ). Despite several previous reports on similar topics and encompassing some of our microalgal species, the wild nature of our strains accounts for the novelty of this work — in addition to the characterization of a few wild cyanobacteria. Eustigmatophyceae class was the best producer of ALA, while Prymnesiophyceae was the best for EPA and ALA. Nodularia harveyana exhibited the highest ALA level (0.611 ± 0.022 mg FA.L culture − 1 .d − 1 ) and Gloeothece sp. was highest in EPA (0.030 ± 0.004 mg FA.L culture − 1 .d − 1 ).