Fig. 2
From: Secretion of collagenases by Saccharomyces cerevisiae for collagen degradation
Optimization of metal ion concentration in culture medium. A YPD medium supplemented with different concentrations of CaCl2; B YPD medium supplemented with different concentrations of ZnCl2; C YPD medium containing 10 mM CaCl2 and supplemented with different concentrations of ZnCl2; D enzymatic assay of collagenase in supernatant using FALGPA (N-(3-[2-furyl]acryloyl)-Leu-Gly-Pro-Ala) as the substrate. The strain B0 harboring the empty plasmid CPOTud was used as control. Papain: 1 mg/mL papain solution. * P < 0.05; ** P < 0.01