title: Feedback stabilization of fed-batch bioreactors: non-monotonic growth kinetics.
abstract: This paper deals with the design of a feedback controller for fed-batch microbial conversion processes that forces the substrate concentration C(S) to a desired setpoint, starting from an arbitrary (initial) substrate concentration when non-monotonic growth kinetics apply. This problem is representative for a lot of industrial fermentation processes, with the baker's yeast fermentation as a well-known example. It is assumed that the specific growth rate mu is function of the substrate concentration only. A first approach exploits the availability of on-line measurements of both the substrate and biomass concentration. A second approach is merely based on on-line measurements of the biomass concentration, which provide an estimate for the specific growth rate. After a reformulation of the substrate concentration setpoint into a specific growth rate setpoint, it is demonstrated that the fed-batch process can still be stabilized around any desired operating point along the non-monotonic kinetics.
mesh_terms: D000465:Algorithms; D019149:Bioreactors; D003198:Computer Simulation; D004867:Equipment Design; D000431:Ethanol / Q000378:metabolism; D005246:Feedback; D007218:Industrial Microbiology / Q000295:instrumentation / Q000379:methods*; D007700:Kinetics; D008954:Models, Biological; D011786:Quality Control; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D012680:Sensitivity and Specificity; D013269:Stochastic Processes
chemical_list: D000431:Ethanol