Cybernetic modeling of bacterial cultures at low growth rates: Mixed-substrate systems.

A cybernetic model to predict the low-growth-rate behavior of bacteria in mixed-substrate environment is presented. Using only growth and maintenance parameters from single-substrate experiments, the model accurately predicts the simultaneous substrate utilization and maintenance energy effects in constant fed-batch cultures of Klebsiella oxytoca. The robustness of the model was examined more rigorously by perturbing glucose-limited fed-batch cultures with additions of arabinose, xylose, and fructose. In all cases, reasonable agreement of the model prediction with the experimental data was observed.