The present invention relates generally to the field of recombinant fatty acid synthesis, particularly in transgenic plants. The application describes genes involved in fatty acid synthesis and provides methods and vectors for the manipulation of fatty acid composition of plant oils. In particular, the invention provides constructs for achieving the integration of multiple heterologous genes involved in fatty acid synthesis into the plant genome, such that the resulting plants produce altered levels of polyunsaturated fatty acids. Also described are methods for enhancing the expression of fatty acid biosynthesis enzymes by co-expressing a silencing suppressor within the plant storage organ.

Provided is a method of producing an oil containing polyunsaturated fatty acids by using Schizochytrium sp. The method comprises: performing fermentation using Schizochytrium sp.; resuspending the resultant cells after fermentation in water, adding cellulase and neutral protease for enzymolysis; mixing the enzymatic hydrolyzate with n-hexane, shaking, extracting, centrifuging, and collecting the n-hexane phase; concentrating the n-hexane phase under reduced pressure to remove the n-hexane, and drying to obtain an oil; performing a first crystallization and a second crystallization, and then performing cold filtration to obtain a liquid oil after the second crystallization; and subjecting the liquid oil to deacidification and decolorization. By regulating fermentation conditions and conducting concentration processing on polyunsaturated fatty acids, the content of eicosapentaenoic acid in the Schizochytrium sp. is increased to more than 12%, and the obtained oil is rich in docosahexaenoic acid, docosapentaenoic acid and eicosapentaenoic acid.

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

Disclosed is a method for producing algae-derived polyunsaturated fatty acids, comprising the steps of a) contacting dry algae with ethanol; b) removing ethanol to obtain crude oil; c) subjecting the crude oil to a transesterification reaction with a lower alcohol to generate fatty acid alkyl esters; d) extracting the fatty acid alkyl esters to result in a phase containing fatty acid alkyl esters; e) collecting the phase containing fatty acid alkyl esters; and f) contacting the collected phase with silica gel. Also disclosed is a method for effectively removing impurities, including chlorophyll, fucoxanthin and beta-carotene, from crude algal fatty acid alkyl esters, comprising contacting the crude algal fatty acid alkyl esters with silica gel in hexane.

The present invention is directed to isolated nucleic acid molecules and polypeptides of thraustochytrid polyunsaturated fatty acid (PUFA) synthases involved in the production of PUFAs, including PUFAs enriched in docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), or a combination thereof. The present invention is directed to vectors and host cells comprising the nucleic acid molecules, polypeptides encoded by the nucleic acid molecules, compositions comprising the nucleic acid molecules or polypeptides, and methods of making and uses thereof.

Provided is a Schizochytrium limacinum strain, a building method therefor and an application thereof. The strain disclosed is classified and named as Schizochytrium sp. HX-RS, and the preservation number is CCTCC NO: M2017046. An acyltransferase functional domain originating from shewanella PKS enzyme is adopted instead of an acyltransferase functional domain originating from schizochytrium sp. PKS enzyme, and the strain is obtained by performing flat panel screening and acclimation screening with a high rotation speed and a low temperature.

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.