A septum is positioned within a disposable vessel and defines a lower chamber and an upper chamber. The septum includes a plurality of apertures that provide fluid communication between the upper chamber and lower chamber. Compressed gas is introduced in the lower chamber to produce fine bubbles rising up throughout the vessel to produce a mixing and gasification needed for the growth of a biological culture and manufacture of a biological product in a nutrient medium. Adding a binding resin to the upper chamber allows harvesting, separation and purification of biological products in the reactor as a single unit operation.