Details

The plots show deoxygenation of the broth, either by sparging with nitrogen or, if the culture consumes oxygen, by stopping the air flow. The dissolved oxygen concentration drops during this period. Air is then pumped into the broth at a constant flow rate and the increase in is monitored as a function of time. The oxygen concentration must remain above , the critical oxygen concentration, when oxygen becomes the limiting substrate of cellular activity [1].

The electrode concentration is given by [2]:

where is the measured dissolved oxygen concentration and is the electrode time constant.

For more information, including the effect of the transfer coefficient, consult the references.

References

[1] P. M. Doran, Bioprocess Engineering Principles, Boston: Elsevier, 1995.

[2] I. J. Dunn, E. Heinzle, J. Ingham and J. E. Prvenosil, Biological Reaction Engineering, 2nd ed., Weinheim, Germany: VCH Verlagsgesellschaft mbH, 2003.