Bioengineering Comamonas testosteroni CNB-1: a robust whole-cell biocatalyst for efficient PET microplastic...

Area of Science:

• Environmental Science
• Biotechnology
• Microbiology

Background:

• Polyethylene terephthalate (PET) microplastic contamination is a growing problem in wastewater treatment.
• Microplastics accumulate in sewage sludge due to a lack of effective removal methods.

Purpose of the Study:

• To investigate the potential of using a novel enzyme, DuraPETase, for PET microplastic degradation.
• To explore the use of Comamonas testosteroni CNB-1 as a whole-cell biocatalyst for in-situ microplastic removal.

Main Methods:

• Secretion of DuraPETase from Comamonas testosteroni CNB-1.
• Assessing DuraPETase hydrolytic activity on p-NPB and PET nanoplastics.
• Evaluating the depolymerization of PET microplastics by CNB-1 whole-cell biocatalysts at ambient temperature.

Main Results:

• Secreted DuraPETase demonstrated significant hydrolytic activity.
• CNB-1 whole-cell biocatalysts degraded 9% of PET microplastics within 7 days at ambient temperature.
• CNB-1 utilized PET degradation intermediates (TPA, EG, BHET) for growth, indicating complete mineralization potential.

Conclusions:

• Activated sludge harbors potent microbial resources for in-situ microplastic removal.
• DuraPETase and CNB-1 whole-cell biocatalysts show promise for tackling PET microplastic pollution in wastewater treatment.