Abstract: The present invention relates to the use of cell cultures in the open continuous mode, to a method for selecting static cell variants or cell variants which proliferate in suspension, to a culture substrate and to a device suitable for implementing this method.

Abstract: The invention relates to a method for continuously, semi-continuously or discontinuously treating a substrate (24) consisting in placing said substrate in a bioreactor receiver (1) and in exposing it to the action of a living cell culture (C1) which makes it possible to carry out a reaction (R1) on the substrate (24) and to which a medium is periodically inoculated with the aid of living cells (C2) improving said reaction. Said living cells (C2) are obtainable by selection from a population of dynamic living cells carried out by an automatic selection device (2) which is supplied by the same substrate (24) as the bioreactor receiver (1) and is originally inoculated with the living cells (C1) contained in the bioreactor receiver (1) tank and an operating device.