Lipid-lowering and anti-inflammatory effects of palmitoleic acid: Evidence from human intervention studies

Screening for the production of polyunsaturated fatty acids and cerebrosides in fungi

AIMS

To investigate fatty acid, including polyunsaturated fatty acids (PUFA), and cerebroside production of a large diversity of fungi from the Ascomycota, Basidiomycota, and Mucoromycota phyla.

METHODS AND RESULTS

Seventy-nine fungal strains were grown in Kavadia medium using a microcultivation system, i.e. Duetz microtiter plates. Following cultivation, fatty acid and cerebroside contents were analyzed by gas chromatography-flame ionization detection (GC-FID) and high performance thin-layer chromatography (HPTLC), respectively. Mucoromycota fungi appeared as the most promising candidates for omega-6 PUFA production. The best omega-6 producer, including γ-linolenic acid (GLA, 18:3n-6), was Mucor fragilis UBOCC-A109196 with a concentration of 647 mg L-1 total omega-6 PUFA (representing 35% of total fatty acids) and 225 mg L-1 GLA (representing 12% of total fatty acids). Arachidonic acid concentration (20:4n-6) was the highest in Mortierella alpina UBOCC-A-112046, reaching 255 mg L-1 and 18.56% of total fatty acids. Interestingly, several fungal strains were shown to produce omega-7 monounsaturated fatty acids. Indeed, Torulaspora delbrueckii strains accumulated palmitoleic acid (16:1n-7) up to 20% of total fatty acids, reaching 114 mg L-1 in T. delbrueckii UBOCC-A-214128, while C. elegans UBOCC-A-102008 produced mainly paullinic acid (20:1n-7) with concentrations up to 100 mg L-1. Concerning cerebroside production, HPTLC appeared as a relevant approach for their detection and quantification. Promising candidates belonging to the Mucoromycota phylum were found, especially in the Absidia genus with A. spinosa UBOCC-A-101332 as the best producer (12.7 mg L-1).

CONCLUSIONS

The present study highlighted PUFA and cerebroside production in a large diversity of fungi and the fact that members of the Mucoromycota phylum are good producers of PUFA as well as cerebrosides.

Biotechnology tools and applications for development of oilseed crops with healthy vegetable oils

Vegetable oils, consisting principally of triacylglycerols (TAG), are major sources of calories and essential fatty acids in the human diet. The fatty acid composition of TAG is a primary determinant of the nutritional quality and health-promoting properties of vegetable oils. TAG fatty acid composition also affects the functionality and properties of vegetable oils in food applications and in food processing and preparation. Vegetable oils with improved nutritional and functional properties have been developed for oilseed crops by selection and breeding of fatty acid biosynthetic mutants. These efforts have been effective at generating vegetable oils with altered relative amounts of saturated and unsaturated fatty acids in seed TAG, but are constrained by insufficient genetic diversity for producing oils with "healthy" fatty acids that are not typically found in major oilseeds. The development and application of biotechnological tools have instead enabled the generation of oilseeds that produce novel fatty acid compositions with improved nutritional value by the introduction of genes from alternative sources, including plants, bacteria, and fungi. These tools have also allowed the generation of desired oil compositions that have proven difficult to obtain by breeding without compromised performance in selected oilseed crops. Here, we review biotechnological tools for increasing crop genetic diversity and their application for commercial or proof-of-principal development of oilseeds with expanded utility for food and feed applications and higher value nutritional and nutraceutical markets.