Growth monitoring and control through computer-aided on-line mass balancing in a fed-batch penicillin fermentation.

A computer-aided methodology is developed for on-line monitoring and control of cell growth in fed-batch penicillin fermentation using a semidefined medium containing low corn steep liquor concentration (5.7 g/L). Cell growth is monitored and controlled with the use of experimental correlation and carbon-balancing equatiions on a real-time basis throughout the fermentation. Through a combination of feed-forward and feedback control of sugar addition, residual glucose concentration in the broth was maintained below 1 g/L and cell-growth rate was kept at constant at preset vaiues. The accuracy and reproducibility of this technique are demonstrated. The use of real-time control of cell growth is expected to aid future investigations of this antibiotic fermentation.