Microalgae as a Source for VLC-PUFA Production

Abstract

Microalgae present a huge and still insufficiently tapped resource of very long-chain omega-3 and omega-6 polyunsaturated fatty acids (VLC-PUFA) for human nutrition and medicinal applications. This chapter describes the diversity of unicellular eukaryotic microalgae in respect to VLC-PUFA biosynthesis. Then, we outline the major biosynthetic pathways mediating the formation of VLC-PUFA by sequential desaturation and elongation of C18-PUFA acyl groups. We address the aspects of spatial localization of those pathways and elaborate on the role for VLC-PUFA in microalgal cells. Recent progress in microalgal genetic transformation and molecular engineering has opened the way to increased production efficiencies for VLC-PUFA. The perspectives of photobiotechnology and metabolic engineering of microalgae for altered or enhanced VLC-PUFA production are also discussed.

Antioxidant activity of alcohol aqueous extracts of Crypthecodinium cohnii and Schizochytrium sp.

“…Microalgae are an attractive alternative resource as they are rich in bioactive chemicals (Encarnação et al, 2015;Luo et al, 2015;Khozin-Goldberg et al, 2016). Much research on the antioxidant effect of different microalgae has been carried out (Safafar et al, 2015;Singh et al, 2016).…”

The lipid biochemistry of eukaryotic algae

“…Likewise, diatoms (in particular Phaeodactylum tricornutum) have attracted attention not only as a source of EPA but also DHA [527,528]. P. tricornutum has been genetically modified to enhance productivity of n-3 VLCPUFAs [529] and its biotechnological economics assessed [530].…”

“…Some relevant studies are [531][532][533] [534]. Moreover, some aspects of genetic modification of algae to enhance productivity are discussed by Khozin-Goldberg et al [527]. In particular, information about TAG accumulation in Chlamydomonas has been applied to the oleaginous microalgae Nannochloropsis sp.…”

“…For DHA, Crypthecodinium cohnii (Dynophyta) and Schizochytrium (Thruastochytriaceae) have been used for several years in the infant formula market [536] ( Table 6). Such algal oils have been shown to be efficacious, non-toxic and of high nutritional value [527].…”

Microalgae with Immunomodulatory Activities

“…Microalgae are important source of polyunsaturated fatty acids and they are able to synthesize both omega 6 and omega 3 fatty acids and several species of microalgae have been characterized for their PUFA production ( Table 2). Considering the continuous reduction of available fishery and seafood resources and the increasing market request of vegan products, microalgae have been considered as valuable alternatives, as well as sustainable and eco-friendly PUFA producers [78]. The omega 6 fatty acids class include γ-linoleic acid (GLA) and arachidonic acid (ARA), the omega 3 fatty acid class include eicosapentaeonic acid (EPA), known as the most abundant PUFA in phytoplankton [79], and docosahexaeonic acid (DHA) ( Figure 2) [80].…”