Fig. 3
From: Fine tuning enzyme activity assays for monitoring the enzymatic hydrolysis of PET
Upgrading the UV-method and monitoring the progression of the LCC-catalyzed PET-hydrolysis. (a) Overlay UV absorbance spectra of terephthalic acid (TPA), mono-(2-hydroxyethyl) terephthalic acid (MHET) and bis-(2-hydroxyethyl) terephthalate (BHET) and their molar absorptivity determined at 235 nm. (b) Monitoring the concentration of each individual product BHET, MHET, TPA and of the global TPA content, during the LCC-mediated enzymatic hydrolysis of the commercial PET film, using the improved internal standard containing HPLC method. (For reaction conditions please see Section “LCC-mediated enzymatic degradation of PET films in the Experimental part”.) (c) Specific PET-hydrolysis activity of the recombinant leaf-branch compost cutinase (LCC) determined by the conventional (HPLCconv.) and internal standard-containing (HPLCint.std.) HPLC methods and by the reported UV-spectroscopy method (UV-A260) or the herein optimized UV-method (UV-A235).
