A bioreactor includes a plurality of spargers and a plurality of vertical circulation loops. A first vertical circulation loop of the plurality of vertical circulation loops includes a first sparging region and a first return region. The first vertical circulation loop is in liquid communication with one or more other loops of the plurality of vertical circulation loops. The first vertical circulation loop is characterized by an individual loop mass transfer coefficient. A controller is coupled to the plurality of spargers and configured to control the plurality of spargers together such that a cumulative mass transfer coefficient of the plurality of vertical circulation loops is within a threshold of the individual loop mass transfer coefficient associated with the first vertical circulation loop.