Alternative Sources of n-3 Long-Chain Polyunsaturated Fatty Acids in Marine Microalgae

Abstract

The main source of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in human nutrition is currently seafood, especially oily fish. Nonetheless, due to cultural or individual preferences, convenience, geographic location, or awareness of risks associated to fatty fish consumption, the intake of fatty fish is far from supplying the recommended dietary levels. The end result observed in most western countries is not only a low supply of n-3 LC-PUFA, but also an unbalance towards the intake of n-6 fatty acids, resulting mostly from the consumption of vegetable oils. Awareness of the benefits of LC-PUFA in human health has led to the use of fish oils as food supplements. However, there is a need to explore alternatives sources of LC-PUFA, especially those of microbial origin. Microalgae species with potential to accumulate lipids in high amounts and to present elevated levels of n-3 LC-PUFA are known in marine phytoplankton. This review focuses on sources of n-3 LC-PUFA, namely eicosapentaenoic and docosahexaenoic acids, in marine microalgae, as alternatives to fish oils. Based on current literature, examples of marketed products and potentially new species for commercial exploitation are presented.

Opportunities to enhance alternative sources of long-chainn-3 fatty acids within the diet

“…rotifers; for review see Martins et al (26) ). Gog et al (34) described a Nannochloropsis oculata with a fatty acid profile containing 49 % EPA, while most commonly Nannochloropsis strains show lower levels, in the range of 11-39 %.…”

“…possess a number of traits that are advantageous for the industry, including high lipid content, elevated DHA production and presentation in the TAG form, as well as good growth in culture under elevated cell concentrations. In Schizochytrium strains, DHA may reach 30-35 % of total fatty acids mainly in TAG fraction (see Martins et al (26) for details).…”

“…The large quantity of oil required throughout the life history of salmonids and marine Table 4. Examples of marine microalgae species characterised by EPA production (adapted from (26) ) EPA content (% TFA) EPA content (% DW)…”

“…Examples of micro-organisms are microalgae (25)(26)(27) including thraustochytrids (28,29) and Escherichia coli (30) .…”

Untitled

“…Microalgae production at commercial scale is highly required in aquaculture industry as well as in the newly developing biodiesel technology. However microalgae production at industrial volume is limited by both difficulties in culture procedures and elevated production costs (Lewis et al, 1999;Hemaiswarya et al, 2011;Martins et al, 2013).…”