Fig. 4
From: Using a marine microalga as a chassis for polyethylene terephthalate (PET) degradation
SEM and UHPLC analysis of PETG film degradation by PETase-FLAG secreted from P. tricornutum. A small piece of PETG film was incubated with 1 ml of supernatant (medium fraction) of a 50 ml culture expressing AP_SP-PETaseR280A-FLAG (clone 1, induced for 4 days) and wild type and analyzed via SEM. As shown in the upper part, similar but more area-wide changes in the surface of the PETG film as observed in the solid approach (PET bottle film degradation by AP_SP-PETaseR280A-FLAG clone 1 on solid medium, Fig. 3) were detected. The wild type control (lower left) did not show any significant aberrations in the surface structure of the PETG film. UHPLC analysis (lower right) of the medium fractions after 1 week of incubation with the PETG film at 30 °C revealed production of TPA and MHET in sample AP_1 (AP_SP-PETaseR280A-FLAG clone 1), which were absent from the wild type control. PETG polyethylene terephthalate glycol, SN supernatant, AP alkaline phosphatase, SP signal peptide, WT wild type, AP1/AP_1 AP_SP-PETaseR280A-FLAG clone 1