An inverted conical bioreactor is provided for growing cells or microorganisms. The bioreactor has an internal space and a perforated barrier within the vessel, through which a liquid may flow, where cells or microorganisms cannot pass through the perforated barrier. The perforated barrier divides the internal space of the bioreactor into a first chamber and a second chamber. Cells are grown within the second chamber and can be perfused by re-circulating the liquid, for example a growth medium, through the bioreactor. Various inlet ports and outlet ports allow controlling the parameters of flow of the growth medium.