An informatics-based analysis platform identifies diverse microbial species with plastic-degrading potential.

Area of Science:

• Environmental Microbiology
• Biotechnology
• Biochemistry

Background:

• Plastic pollution is a global environmental crisis, necessitating innovative solutions.
• Bioremediation using microbial enzymes offers a promising strategy to degrade plastic waste.
• Existing plastic-degrading enzymes like PETase and MHETase provide a basis for discovering new candidates.

Purpose of the Study:

• To identify novel microbial enzymes capable of degrading plastic polymers.
• To characterize the phylogenetic and structural properties of potential plastic-degrading enzymes.
• To experimentally validate the plastic-degrading capabilities of identified microbial candidates.

Main Methods:

• Utilized sequence motif analysis, phylogenetic inference, and machine learning-guided 3D protein structure prediction.
• Screened microbial protein-coding sequences for similarity to known plastic-degrading enzymes (PETase and MHETase).
• Performed plate clearing assays to test the enzymatic activity of Pseudomonas stutzeri on various synthetic polymers.

Main Results:

• Identified hundreds of PETase-like and fewer MHETase-like enzymes across diverse microbial taxa.
• Phylogenetic analysis showed distinct clades for plastic-degrading enzymes compared to ancestral sequences.
• Demonstrated that Pseudomonas stutzeri can degrade polyurethane, polycaprolactone, and utilize polystyrene as a carbon source.

Conclusions:

• An integrated bioinformatics and experimental approach rapidly identifies and validates novel plastic-degrading enzymes.
• Pseudomonas stutzeri possesses enzymes capable of degrading multiple types of synthetic polymers.
• This research provides a foundation for developing new bioremediation technologies to combat plastic pollution.