Patent ID: 7819576

Claim:
A pneumatic bioreactor comprising: a containment vessel formed from a resilient material; at least one gas supply line in communication with said vessel; and at least one buoyancy-driven mixing device comprising: a mixing wheel mounted within said containment vessel so as to be rotatable about a substantially horizontal, central axis; a plurality of gas trapping members extending along an outer periphery of said wheel, wherein said gas supply line terminates below said gas trapping members and wherein said gas trapping members are configured to entrap rising gas bubbles introduced into said containment vessel through said gas supply line to thereby cause said mixing wheel to rotate about said central axis in a first direction; and at least one mixing vane disposed radially inwardly from said gas trapping members and extending axially with respect to said central axis so as to be configured to agitate fluid contained in said containment vessel as said mixing wheel rotates about said central axis.