A prescription for engineering PFAS biodegradation.

Area of Science:

• Environmental Science
• Biotechnology
• Microbiology

Background:

• Per- and polyfluorinated chemicals (PFAS) are persistent environmental pollutants.
• PFAS pose risks to human health and resist microbial degradation.
• Current understanding suggests C-F bond strength or fluoride toxicity limits microbial breakdown.

Purpose of the Study:

• To review strategies for enhancing microbial degradation of PFAS.
• To advocate for laboratory-based engineering and evolution approaches.
• To identify key steps for achieving in vivo PFAS biodegradation.

Main Methods:

• Reviewing existing literature on PFAS recalcitrance and defluorination enzymes.
• Proposing a strategy combining metabolic engineering and directed evolution.
• Identifying necessary biological components for successful PFAS bioremediation.

Main Results:

• Enzymes capable of defluorination exist across all Enzyme Commission classes.
• Successful biodegradation requires engineered microbes tolerant to high fluoride levels.
• Developing enzymes with broader substrate specificity and positive selective pressure for PFAS is crucial.

Conclusions:

• Laboratory evolution offers a promising route to engineer microbes for PFAS degradation.
• A multi-pronged approach involving enzyme engineering and microbial adaptation is necessary.
• Overcoming fluoride toxicity and enhancing C-F bond cleavage are key challenges.