Patent ID: 7579174

Claim:
A process for growing microorganisms of the order Thraustochytriales and producing at least about 20% of their biomass as lipids comprising conducting a fermentation of the microorganisms in a medium comprising a carbon source, microorganisms and a limiting nutrient source: wherein earlier during the fermentation the dissolved oxygen content of the fermentation medium is at least about 4% of saturation and later during the fermentation the dissolved oxygen content of the fermentation medium is less than about 3% of saturation; wherein the fermentation of the microorganisms in the fermentation medium increases the biomass density of the fermentation medium when the carbon source and limiting nutrient source are present in the fermentation medium and when the dissolved oxygen content of the fermentation medium is at least about 4% of saturation; wherein the fermentation of the microorganisms in the fermentation medium produces lipids containing polyenoic fatty acids when the dissolved oxygen content of the fermentation medium is less than about 3% of saturation; wherein the process produces at least an average rate of about 0.5 grams of lipids per liter of fermentation medium per hour of the fermentation; and wherein at least about 15% of the total lipids produced by the microorganisms are polyunsaturated lipids.