Kinetics of growth and medium de-acidification for Geotrichum candidum and Penicillium camemberti cultivated on complex liquid media

Growth kinetics of Geotrichum candidum and Penicillium camemberti in submerged cultures under conditions of low aeration rate and uncontrolled pH were continuously recorded turbidimetrically. In these conditions the exponential growth phase was short, and ceased at a total biomass concentration of about 0.5 gl(-1) for G. candidum and 0.8 gl(-1) for P. candidum. The succeeding linear growth phase was also short, and its end corresponded to a biomass of 1.5 and 2.5 gl(-1) for G. candidum and P. camemberti respectively. A fair growth was recorded for P. camemberti on peptone-lactate medium, but G. candidum required addition of trace elements. For neither of these species growth was stimulated by growth factors of yeast extract. In peptone-lactate medium, the final pH did not depend on supplementation: 8-8.4 was recorded for G. candidum and 8.7-8.8 for P. camemberti.