AbstractThe mode of ethanol action on both the steady‐state and the dynamic properties of K. aerogenes was investigated using a nitrogen‐limited chemostat. Reduction in the maximum growth rate (μm) suggests that noncompetitive enzyme inhibition could occur, but Lineweaver–Burk analysis showed the inhibition to be more complex. A consistent mechanism of inhibition was established for 0–3% v/v ethanol. Warburg manometric experiments indicated that inhibition occurred in pathways located in the intact cell wall. Frequency response analysis, using sinusoidal variations in the dilution rate showed that ethanol increased the time constant of the metabolic parameter, QAC. The system was stable in the presence of ethanol and showed no evidence of oscillations following a disturbance.