A bacterial culture having a specific oxygen uptake rate of 5 mmol O₂ (g DCW)^-1 hr^-1 is being grown aerobically in a fed-batch bioreactor. The maximum value of the volumetric oxygen transfer coefficient is 0.18 s^-1 for the stirred tank bioreactor and the critical dissolved oxygen concentration is 20% of the saturation concentration (8 mg mL^-1). The maximum density to which the cells can be grown in the fed-batch process without the growth being limited by oxygen transfer, is approximately