(eng): This paper makes a step towards practical applicability of the optimal control for industrial penicillin production. Using the nonlinear gradient method as the key optimization tool, two ways of measurement feedback incorporation into the optimization procedure are proposed. Firstly, the receding horizon approach (whose linear variant is widely spreading in the field of operation of various industrial processes) is investigated considering different lengths of optimization horizon. Secondly, the shrinking horizon approach inspired by the character of the solved task with terminal criterion is examined. In order to make the latter comparable to the receding horizon approach, various sampling periods of the input signal are considered. Utilization of the nonlinear continuous time model of the controlled process clearly distinguishes this paper from the earlier publications.