AUTOMATIC CONTROL SYSTEM FOR GROWTH RATE OF MICROORGANISMS

摘要

The invention relates to a bioreactor automatic control system and a method, in particular automatic control system allowing the control of microbial cultures processes. The proposed automatic control system controls the flow of the nourishing substrate stream in to the bioreactor so that a specific growth rate of microorganisms would be ensured. Microbial growth rate is determined indirectly by measuring the oxygen consumption rate of the cultivated culture in the bioreactor. The control system comprises a combined controller which forms the common nourishing substrate stream from two parts: the base substrate flow is determined by the correlation between the consumption of the substrate and amount of oxygen needed to oxidise it, and the adjusting substrate flow is determined depending on the error between the set and the monitored oxygen consumption ratio. The set oxygen consumption rate is additionally adjusted according to the ratio of set oxygen amount and monitored consumed oxygen amount in bioreactor. Parameters of automatic controller are modified adaptively, depending on the oxygen consumption rate of microorganism culture.