It is particularly difficult to control a biotechnological process because of significant sensitivity of living organisms cultured in bioreactors to process parameters and environmental conditions. Varying conditions of the process are also significant (a change in the chemical composition of the substrate or a change in the mass exchange conditions resulting from the modification of rheological parameters). The industrial biomass cultivation processes require the optimal biomass growth rate. In order to ensure it, it is necessary to analyze input variables, find the most representative output variables, and design an adequate automated control strategy, which should be tailored to a given bioprocess. The article analyzes selected automated control systems in fed-batch biomass cultivation bioprocesses presented in reference publications concerning bioprocess control. Open-loop and closed-loop control systems were taken Into consideration. The research showed that open-loop control systems could not respond to process disturbances such as unexpected variations in input variables. Therefore, the authors analyzed closed-loop control systems in more detail, especially the feedback control systems with proportional-integral (PI) control action, which were used to stabilize the specific growth rate at a desired level. The authors presented equations which enable the online estimation of the specific growth rate on the basis of cellular metabolic heat. It has been noticed that the quality of automated control of bioprocesses can be further improved through improvement of control systems with a feedback.