Figure 4From: Casein phosphopeptides drastically increase the secretion of extracellular proteins in Aspergillus awamori. Proteomics studies reveal changes in the secretory pathwayDephosphorylation of casein with "antartic" alkaline phosphatase and effect of the dephosphorylated casein on chymosin secretion. A. SDS-PAGE (12%) of casein and dephosphorylated casein after alkaline phosphatase treatment. Four subunits of casein were detected after blue-silver Colloidal Coomassie staining (left). ProQ Diamond Staining (rigth) showed a significant decrease in the signal intensity of the bands corresponding to the dephosphorylated subunits of casein (subunits β and κ) after treatment with "antartic" alkaline phosphatase (lane +AP). Tandem mass spectrometry was used to identify the casein subunits. B. Production of chymosin at 24 and 48 h in cultures without any addition, supplemented with 10 g/L or 5 g/L casein (C+) or with 5 g/L partially dephosphorylated casein (C+P-). C. Production of chymosin at 24 and 48 h using MDFA3 medium without supplement, supplemented with 3 g/L casein, or with 3 g/L commercially dephosphorylated casein (Sigma).Back to article page