Provided herein are eukaryotic microorganisms having a simple lipid profile comprising long chain fatty acids (LCFAs). Also provided are compositions and cultures comprising the eukaryotic microorganisms as well as methods of using the eukaryotic microorganisms.

The invention provides isolated nucleic acid molecules which encode novel fatty acid desaturases and elongases from the organism Emiliana huxleyi. The invention also provides recombinant expression vectors containing desaturase or elongase nucleic acid molecules, host cells into which the expression vectors have been introduced, and methods for large-scale production of long chain polyunsaturated fatty acids (LCPUFAs), e.g. arachidonic acid (ARA), eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA).

Provided herein are methods of culturing a microorganism. The methods include providing a container comprising one or more microorganisms in a medium, which has a first carbon to nitrogen ratio; culturing the microorganisms until the culture reaches a threshold indicator; harvesting a portion of the culture while maintaining the majority of the culture in the container; and adding fresh medium comprising a second carbon to nitrogen ratio to the container with the majority of the culture comprising the microorganisms.

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 disclosure provides culture or fermentation media including a biomass or derivative thereof of a hemoprotein-producing C.sub.1 metabolizing non-photosynthetic bacterium, methods of culturing cells or tissue with the culture or fermentation medium, and products produced by the culturing methods including food products, food ingredients, phytoprotective bacterial cell products, and other products of interest such as vitamins, fatty acids, amino acid, carotenoids, etc.

The present disclosure provides culture or fermentation media including a biomass or derivative thereof of a hemoprotein-producing C.sub.1 metabolizing non-photosynthetic bacterium, methods of culturing cells or tissue with the culture or fermentation medium, and products produced by the culturing methods including food products, food ingredients, phytoprotective bacterial cell products, and other products of interest such as vitamins, fatty acids, amino acid, carotenoids, etc.

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.

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.