Careful consideration of the bioreactor agitation and aeration system is required in order to maintain a homogeneous environment and provide sufficient oxygen transfer rates to meet cellular metabolic requirements.

Both agitation and aeration need to be considered together as they have an influence on the mechanical design of the fermenter, the oxygen transfer characteristics of the vessel and its power requirements.

There are a number of components that contribute to the aeration and agitation system efficiency including the height/diameter ratio. These are:

i. the impeller system (marine, flat-blade turbine etc)
ii. the baffles (can also provide additional cooling capability)
iii. the air sparger (ring, cross orifice, porous, nozzle)
iv. the drive seal (mechanical, magnetic)