IN-SITU GLOBAL METHOD FOR MEASUREMENT OF OXYGEN-DEMAND AND MASS-TRANSFER

Two aerobic microorganisms, Saccharomycopsis lipolytica and Brevibacte rium lactofermentum, have been used in a study of mass transfer and ox ygen uptake from a global perspective, using a closed gas system. Oxyg en concentrations in the gas and liquid were followed using oxygen ele ctrodes; the results allowed for easy calculation of in situ oxygen tr ansport. The cell yields on oxygen for S. lipolytica and B. lactoferme ntum were 1.01 and 1.53 g/g, respectively. The mass transfer coefficie nt was estimated as 10/h at 500 rpm for both fermentations. The advant ages with this method are noticeable, since the use of model systems m ay be avoided, and the in situ measurements of oxygen demand assure re liable data for scale-up.