Application of adaptive DO-stat feeding control to Pichia pastoris X33 cultures expressing a single chain antibody fragment (scFv)

摘要: In this study, fed-batch cultures of a Pichia pastoris strain constitutively expressing single chain antibody fragment (scFv) under the control glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter were performed in pilot 50 L bioreactor. Due to very high cell density achieved within first 75 h, typically between 140 and 160 g-DCW/L dry weight (DCW), most scFv is produced hard oxygen transfer limitation. To improve productivity, direct adaptive dissolved (DO)-stat feeding controller that maximizes glycerol constraint available capacity was developed applied process. The enabled maximize through regulation DO concentration 3 5 % saturation, thereby improving process productivity. Set-point convergence dynamics are characterized by fast response upon large perturbations DO, followed slower but robust vicinity boundary with almost imperceptible overshoot. Such performance operating closer 0 for longer periods time when compared traditional proportional–integral–derivative algorithm, which tends destabilize increasing density.