Palmitic acid and long-chain polyunsaturated fatty acids dominate in mycelia of mangrove Halophytophthora and Salispina species in Taiwan

Abstract

Marine oomycetous species produce, among other fatty acids, omega-6 arachidonic acid (ARA) and omega-3 eicosapentaenoic acid (EPA), with implications for the industrial potential of this group of organisms and the need to find an isolate with high production. This study screened 14 isolates of marine oomycetous species: Halophytophthora avicenniae, H. batemanensis, H. exoprolifera, H. polymorphica and Salispina spinosa cultured from fallen mangrove leaves in Taiwan for 24 saturated and unsaturated fatty acids in their mycelia. This paper is the first to report C18:1n-7 vaccenic acid, C20:1 eicosenoic acid, C24:1 nervonic acid, C20:2n-6 eicosadienoic acid, C22:4n-6 adrenic acid, C20:4n-3 eicosatetraenoic acid and C22:5n-3 docosapentaenoic acid in mycelia of Halophytophthora and Salispina species, and the fatty acid profiles of H. batemanensis and H. exoprolifera. Five fatty acids were dominant in the mycelia of the isolates, i.e. C16:0 palmitic acid, C18:1n-9 oleic acid, C18:2n-6 linoleic acid, C20:4n-6 arachidonic acid and C20:5n-3 eicosapentaenoic acid. For the essential fatty acids, S. spinosa produced the highest level of arachidonic acid (27–31% of total fatty acid (TFA), 141–188 mg l−1 yield) while H. avicenniae IMB212 produced the highest percentage of EPA (15% of TFA) while H. polymorphica IMB227 produced the highest yield (96 mg l−1). Different species and isolates of the same species produced different fatty acid profiles, and further research effort may yield a high production isolate of industrial significance and also important fatty acids from the marine environment.

Unravelling the Lipids Content and the Fatty Acid Profiles of Eight Recently Described Halophytophthora Species and H. avicennae from the South Coast of Portugal

“…S13005YL-3.1 produced a higher percentage of ARA when grown in V8 (pH 6; 10 ppt), compared to V8 (pH 8; 30 ppt). V8 media, like the one used in this study, PYG media and even a mix of both are the most widely used culture media in studies on the production of FAs by oomycetes and Thraustochytrids [31][32][33][34][35]44]. Owing to their production from commercially available vegetable juice, V8 media cannot as easily be manipulated as PYG, in which the concentrations of each component can be optimised to enhance FA production.…”

“…As a result, the opportunity to expand the limited knowledge regarding FA production by Halophytophthoras emerged. All studies previously published on Halophytophthora FAs were conducted on isolates from mangroves in Taiwan or the Philippines [31][32][33][34][35], while this study aimed to bring new insights on FAs produced by all nine Halophytopthora species isolated along the Algarve coast from different ecosystems (salt marshes and estuaries), and to unravel interspecific differences in FA profiles and analyse how these relate to their phylogenetic position. Since there is variability in the production of FAs among different species and even isolates from the same species, it is of value to investigate the FA profiles of newly described species to screen for species that produce more interesting profiles.…”

Recent Development of Advanced Biotechnology in the Oleaginous Fungi for Arachidonic Acid Production

“…These characteristics make M. alpina a remarkable industrial host for the production of ARA. In addition, ARA synthesis pathways were also introduced into heterologous hosts, such as Pichia pastoris and Saccharomyces cerevisiae , or more recently Yarrowia lipolytica , as well as the nonmodel organism Salispina spinosa . Notably, the genetic manipulation toolbox for these model organisms and industrial yeasts is more sophisticated than that of filamentous fungi.…”

“…In addition, ARA synthesis pathways were also introduced into heterologous hosts, such as Pichia pastoris 11 and Saccharomyces cerevisiae, 12 or more recently Yarrowia lipolytica, 13 as well as the nonmodel organism Salispina spinosa. 14 Notably, the genetic manipulation toolbox for these model organisms and industrial yeasts is more sophisticated than that of filamentous fungi. As a result, novel metabolic engineering strategies such as enzyme fusion and site-directed mutagenesis based on membrane topology 13,15 were adopted for improving ARA biosynthesis.…”