The disclosed subject matter relates generally to a method for modifying oil, and specifically to a process for increasing the concentration of polyunsaturated fatty acid in an oil composition. The process comprises a) hydrolysis of the glyceride by Thermomyces lanuginosus lipase, b) separation of the free saturated fatty acids from the glycerides and c) enzymatic esterification of the hydrolyzed glyceride by Candida antarctica lipase B with a polyunsaturated fatty acid.

Provided herein are methods for producing one or more polyunsaturated fatty acids. The methods include the steps of providing a microorganism capable of producing polyunsaturated fatty acids, providing a medium comprising a high concentration of one or more carbon sources, low pH, or both, and culturing the microorganism in the medium under sufficient conditions to produce the one or more polyunsaturated fatty acids. Also provided are methods of culturing one or more microorganisms. The methods include culturing the microorganisms in a medium comprising a first amount of one or more carbon sources at a first concentration level, monitoring a carbon source concentration until the carbon source concentration is reduced below the first concentration level, and adding to the medium a second amount of one or more carbon sources to increase the carbon source concentration to a second concentration level.

Methods for harvesting microalgae, comprise providing water containing microalgae, providing flocculant in an amount to form flocs of microalgae when mixed with the water, generating a mixture of the water and the flocculant and separating the flocs from the mixture.

The present invention provides a lipoxygenase that enables the highly efficient formation of an oxide of a highly unsaturated fatty acid or an oxide of a highly unsaturated fatty acid derivative from a highly unsaturated fatty acid or a highly unsaturated fatty acid derivative. The present invention provides a lipoxygenase that enables the highly efficient formation of 8-hydroxyeicosatetraenoic acid from arachidonic acid, the highly efficient formation of 8-hydroxyeicosapentaenoic acid from eicosapentaenoic acid, and the highly efficient formation of 10-hydroxy docosahexaenoic acid from docosahexaenoic acid. Specifically, the present invention provides a polynucleotide that comprises the nucleic acid sequence represented by SEQ ID NO: 1 and 3, or a homolog thereof, and a polypeptide that comprises the amino acid sequence represented by SEQ ID NO: 2 and 4, or a homolog thereof. Also provided is a composition that comprises a membrane protein of an organism belonging to the class Malacostraca and is for carrying out a lipoxygenase reaction.

According to the invention, it has been found that when the amount of sulfate used in the culturing of PUFAs-producing cells is selected such that the sulfate concentration in the last phase of fermentation is always above zero, but at the same time always below the saturation limit of the cells, a biomass is obtained which has an increased proportion by mass of polyunsaturated fatty acids (PUFAs) in the final product, the process having at the same time a high product/substrate yield and space/time yield.

According to the invention, it has been found that when the amount of sulfate used in the culturing of PUFAs-producing cells is selected such that the sulfate concentration drops to zero in the last phase of the growth phase of the cells, an easily disruptable biomass is obtained which has an increased proportion by mass of polyunsaturated fatty acids (PUFAs) in the final product.

The present invention relates to a process for the production of polyunsaturated fatty acids in an organism by introducing, into the organism, nucleic acids which encode polypeptides with Δ5-elongase activity. Advantageously, these nucleic acids can be expressed in the organism together with further nucleic acids which encode polypeptides of the biosynthesis of the fatty acid or lipid metabolism. Especially advantageous are nucleic acids which encode Δ6-desaturases, Δ5-desaturases, Δ4-desaturases and/or Δ6-elongases. These desaturases and elongases are advantageously derived from Thalassiosira, Euglena or Ostreococcus. The invention furthermore relates to a process for the production of oils and/or triacylglycerides with an elevated content of long-chain polyunsaturated fatty acids, and oils and/or triacylglycerides thus obtained. The invention also relates to the nucleic acids, and constructs, vectors and transgenic organisms comprising the same, as well as oils, lipids and/or fatty acids produced by the process according to the invention and to their use.

The present invention relates to methods of synthesizing long-chain polyunsaturated fatty acids, especially eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid, in recombinant cells such as yeast or plant cells. Also provided are recombinant cells or plants which produce long-chain polyunsaturated fatty acids. Furthermore, the present invention relates to a group of new enzymes which possess desaturase or elongase activity that can be used in methods of synthesizing long-chain polyunsaturated fatty acids.

The present invention is directed to isolated microorganisms as well as strains and mutants thereof, biomasses, microbial oils, compositions, and cultures; methods of producing the microbial oils, biomasses, and mutants; and methods of using the isolated microorganisms, biomasses, and microbial oils.

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.