Oxygen-assisted fermentation process

In a fermentation process, the process including the steps of placing a fermentation medium in a vessel, maintaining the fermentation medium in the vessel for a sufficient time to enable a fermentation process to occur in the vessel, and withdrawing a product from the vessel,

• The improvement comprising injecting a stream of substantially pure oxygen into the vessel while the fermentation process is occurring, wherein the stream of substantially pure oxygen is the sole reactive gas, from any source external to the vessel that is injected into the vessel, and wherein the stream of substantially pure oxygen is the only gas that is injected continuously into the vessel, and
• wherein the stream of substantially pure oxygen is moved through the vessel solely due to pressure in an oxygen supply and
• wherein the process is performed without mechanical agitation of contents of the vessel, and wherein the process includes measuring a concentration of oxygen in a head space in the vessel, recycling gas from the head space into the vessel if the concentration of oxygen is greater than a predetermined level, and venting gas from the head space to a region outside the vessel if the concentration of oxygen is less than a predetermined level.