The present invention relates to polynucleotides from Ostreococcus lucimarinus which code for desaturases and elongases and which can be employed for the recombinant production of polyunsaturated fatty acids. The invention furthermore relates to vectors, host cells and transgenic nonhuman organisms which comprise the polynucleotides, and to the polypeptides encoded by the polynucleotides. Finally, the invention also relates to production processes for the polyunsaturated fatty acids and for oil, lipid and fatty acid compositions.

The invention relates to production of a yeast strain with increased mannan oligosaccharides, amino acids, and complex carbohydrates. The invention further relates to the process to propagate and ferment such yeast. The invention further relates to methods of use of the yeast as a feed additive for animals and a food product for humans.

In accordance with the invention, it was found, surprisingly, that a polyunsaturated fatty acids (PUFAs)-comprising biomass with other feedstuff components can be extruded at a low energy input of 12-28 Wh/kg to give an extrudate with a very high oil load capacity.

Process for enriching microalgal biomass, in particular of the genus Nannochloropsis, with different polyunsaturated fatty acids, primarily docosahexaenoic acid (22:6 n-3, DHA), using oils that are rich in these fatty acids. The process comprises the following steps: Preparing a solution or an emulsion of lipids+emulsifying agent (BSA), Preparing the biomass concentrate to obtain a final concentration of mg/ml or greater, Enriching the biomass concentrate by adding the lipids or the emulsion thereof to the microalgal concentrate, Allowing the mixture to rest under constant stirring for at least 24 hours under lighting conditions.

The process allows for the simultaneous enrichment of microalgal biomass of the genus Nannochloropsis with eicosapentaenoic acid (20:5 n-3) (EPA) and docosahexaenoic acid (22:6 n-3) (DHA), to obtain a minimum EPA:DHA weight ratio of 10:1, with an EPA content of at least 10% of the total fatty acid content.

According to the invention, it was found that, surprisingly, a feedstuff having a very high abrasion resistance and very high water stability can be obtained when a PUFA-containing biomass having a high sulphate content is used for producing the feedstuff.

According to the invention, it was found that, surprisingly, a feedstuff having a very high abrasion resistance and very high water stability can be obtained when a PUFA-containing biomass having a high sulphate content is used for producing the feedstuff.

According to the invention, it has been found that a particulate biomass containing an oxidation-sensitive material of value can be converted into a particularly easy-to-handle product in a gentle manner if it is subjected to a granulation with the addition of an agglomeration auxiliary.

According to the invention, it was found that culturing of PUFA-producing cells in a content of sulphate makes it possible to obtain a biomass having high cell stability and thus PUFAs protected against oxidation in a sustained manner, which biomass can in addition be advantageously further processed into a feedstuff.

According to the invention, it was found that culturing of PUFA-producing cells in a content of sulphate makes it possible to obtain a biomass having high cell stability and thus PUFAs protected against oxidation in a sustained manner, which biomass can in addition be advantageously further processed into a feedstuff.

An extruded, pressed or particulate fish feed is described. Also described is a method for reduction of the content of undesired nutrients in water discharged from a fish farm, and a process for increasing the mechanical strength or shear resistance of faeces from fish in a fish farm.