Interfacial adsorption of microorganisms and its effect on oxygen absorption by fermentation broths

Steady-state mass transfer experiments were done to determine whether certain strains of bacteria in homogeneous suspension will accumulate at the gas:liquid interface and thereby significantly increase the oxygen transfer rate to the suspension. In particular, with suspensions of B. licheniformis , the measured transfer rates are as much as three times the rate expected for a uniform suspension. In contrast, suspensions of M. luteus show no increase in oxygen flux above expected values. The fact that B. licheniformis is motile, whereas M. luteus is not suggests that cell motility may play an important role in the accumulation process.