Patent ID: 8769868

Claim:
A method of producing a diatom, the method comprising: a. cultivating diatoms in heterotrophic culture containing a nutrient solution comprising: (i) a nitrogen source and an organic carbon source at an initial concentration of at least 0.5 M carbon, (ii) a molar ratio of organic carbon to nitrogen of no higher than 30:1 (mol C:mol N), and (iii) a non-limiting source of silicate at a concentration of 150 μM to 1.3 mM at all times during the culture; and b. recovering the diatom from the heterotrophic culture, wherein the cultivating conditions result in production of a diatom having at least 1.5% (w/w) of dry weight as eicosapentaenoic acid and an eicosapentaenoic acid to arachidonic acid ratio of at least 14:1.