[Effect of the agitation intensity and concentration of surface-active substances on the rate of oxygen sorption by a model sulfite-albumin medium].

The physicochemical properties of a model medium consisting of two substances, sodium sulfite and albumin, were studied. It was shown that the presence of a SAS in the sulfite solution significantly lowered the rate of oxygen sorption by the model medium. The higher the SAS concentration, the lower the sorption rate. When yeasts were grown on sulfite liquor under conditions of the reduced medium the rate of their growth and respiration did not significantly depend on aeration within wide ranges of its variation. The experiments with the model medium demonstrated that the aeration independence was due to indifference to oxygen not of the cells but of the medium as the result of its physicochemical properties. The effect of sorption hysteresis was also studied on the model medium. It was revealed that the rate of oxygen desorption from the medium was lower than that of oxygen sorption by the same medium. The effect was not observed when a nonionic SAS was added to the medium and the isoelectric point was almost reached. The effect was connected with impairment of oxygen diffusion through the medium surface film. Interaction of the substances included in the model medium was of physical nature.