Fig. 3: Optimization of the conditions for the deglycosylation of IsPETase-Pp.

a The enzymatic activity of IsPETase-Pp with or without deglycosylation. S: the supernatant of the high-density fermentation; D: dialyzed supernatant of the high-density fermentation; D + Endo H: dialyzing prior to deglycosylation with Endo H; Endo H + D: deglycosylation with Endo H prior to dialyzing, D + PNGase: dialyzing prior to deglycosylation with PNGase F. 30 °C indicates the hydrolytic activity of the samples measured at 30 °C; 55 °C indicates the residual activity after incubated at 55 °C for 1 h. To analyze the enzyme activity, 0.4 mg of enzyme and 3 mg of amorphous PET were incubated in 1 mL of 50 mM glycine-NaOH buffer (pH 9.0) for 6 h at 30 °C. b The enzyme activity of IsPETase-Pp after treated with Endo H for 0.5, 1.0 and 1.5 h. The thermostability were measured after the samples were incubated at 55 °C for 0, 0.5, 1, 1.5, and 2 h. Data are presented as mean ± SD.