A rule-based fuzzy logic control is developed for control of penicilli
n concentration in a fed-batch bioreactor. The membership functions, f
uzzy ranges for the error and for the controller output are defined. A
fuzzy rule base is constructed relating error to the control output b
ased on operators' knowledge. The performance of the fuzzy-logic contr
oller is evaluated by simulating a mathematical model of the fed-batch
bioreactor.