Abstract: Bioreactor apparatus for culture of living matter in a liquid medium includes a plurality of tubes connected at one end to a primary manifold section and at their other end to a secondary manifold section such that a flow of liquid containing the living matter can be established within the manifolds and tubes. The flow of liquid medium in such manifolds and/or tubes is capable of control by at least one gas injection device in communication with the primary manifold section and at least one gas injection device in communication with the secondary manifold section. Such an arrangement provides finer control of the flow conditions in the tubes forming part of the bioreactor and of the environmental conditions for culture of the living matter. The arrangement can have a relative simplicity of design which also permits a reduction in the total number of tanks and/or control loops usually associated with bioreactor apparatus of this type.