This paper presents the structure and application of an object-oriented software and hardware control system for anaerobic bioreactors. The proposed system performs real time analysis and storing up a database of information about the processes occurring in the bioreactors. The developed controller is conformed to the system requirements. Some experimental results were obtained on the influence of the stirring duration on the biogas yields and the electrical energy consumption at mesophilic and thermophilic operation modes. The obtained practical results at this stage confirm the usefulness of the proposed control of the stirrer drives of the bioreactors, in certain cases allowing to lower the intrinsic electrical energy consumption, simultaneously considering the biogas yields.