Bioconversion of the Lactose in Whey Ultrafiltrate by Cultivation of Kluyveromyces Marxianus Var. Lactis MC5

ABSTRACT

We have established the interdependence between the air flow rate, lactose assimilation and cell protein synthesis during batch cultivation of Kluyveromyces marxianus var. lactis MC5 strain in a nutrient medium containing cheese whey ultrafiltrate with varying lactose concentrations (40.0 g/L, 78.0 g/L, 124.0 g/L), (NH₄)₂HPO₄ - 6.0 g/L, yeast extract - 5.0 g/L, pH=5.0, at 29 °C in bioreactors ABR 02M (2.0 L), Bulgaria, and MBR AG (15.0 L), Switzerland. Maximum lactose conversion has been achieved by maintaining dynamic control on the air flow rate throughout the process. The outcome of the fermentation process has been determined by the efficiency factor Y_x/s, which is 0.79 for the ABR 02M system, and 0.9 for MBR AG.