Fig. (3) Cultivation of L. lactis in the 100 mL-fixed-bed bioreactor. Time course of cell density, pH, lactose and lactate concentration in harvest flow as well as average volume specific lactate production rate q^*_Lac,FB in interval with fixed dilution rate. M17-Medium (Difco) with 5 g L^-1 lactose, carrier: VitraPOR^® 4 mm.