The control of continuous stirred bioreactors using productivity signal feedback consists of using the direct relation between the optimal static dilution rate and the optimal static productivity. This strategy drives the bioprocess to its optimal productivity point, irrespective of the feeding substrate concentration, and specific growth rate or substrate concentration estimates. While the algorithm covers a wide class of bioprocesses, explicit relations are given for the Monod and Haldane cases. (C) 2012 Elsevier Ltd. All rights reserved.