Fig. 2
Aerobic, glucose-limited retentostat cultures of VHH-secreting K. phaffii. Retentostat cultures were initiated from chemostat cultures operated at D = µ = 0.025 h−1 at time-point zero. Shown are A the total (CX) and viable (CXv) biomass accumulation profiles and the glucose concentration (CS) in the feed throughout the retentostat phase as well as corresponding model-based predictions. B Estimates of the specific glucose uptake rate (qS), μ and the average mS calculated based on non-linear regression analysis. C VHH titer (CP) in supernatants as well as corresponding model predictions based on extrapolation from chemostat data. D Ratio of the VHH-titer measured in supernatants (CP_R) and filtrates (CP_F) at the respective sampling point. E Representative SDS-PAGE of retentostat supernatants and VHH standard. Protein bands were visualized by silver-staining. F Relationship between qP and µ as well as corresponding model predictions based on extrapolation from chemostat data