EN
Basic modes of bioreactor operation (bath, semicontinuous and continuous), and main culture systems (suspended growth, attached growth on microcarriers) are shortly described.Main problem in bioreactor design and operation, including hydrodynamics, heat and mass transfer, cell viability, measurement and control, are discussed.Some particular problems: mixing systems, air supply systems, power dissipation, external and internal diffusion are discussed in a greater detail.Examples of specific reactor design are given, namely: stirred tank reactors, bubble columns, gas lift reactors, liquid jet reactors, packed bed reactors fluidised bed reactors, membrane reactors.New research problem are outlined.