Harnessing extremophilic carboxylesterases for applications in polyester depolymerisation and plastic waste recycling

Area of Science:

• Biotechnology and Environmental Science
• Polymer Chemistry and Engineering

Background:

• Synthetic plastic production leads to significant environmental pollution, global warming, and oil depletion.
• Existing recycling methods are insufficient, necessitating advanced technologies for chemical feedstock recovery and upcycling.

Purpose of the Study:

• To review microbial carboxylesterases (polyesterases) for synthetic polyester degradation, focusing on polyethylene terephthalate (PET).
• To discuss advancements in discovering and engineering polyesterases for industrial applications in plastic recycling.

Main Methods:

• Literature review of microbial carboxylesterases and their application in polyester degradation.
• Discussion of protein engineering strategies to enhance enzyme activity and stability.
• Exploration of enzyme cocktails and secreted protein expression for mixed plastic recycling.

Main Results:

• Microbial carboxylesterases show potential for enzymatic depolymerization of polyesters under mild conditions.
• Natural esterases often lack sufficient activity and stability for industrial polyester recycling.
• Protein engineering and discovery of novel enzymes are crucial for improving efficiency.

Conclusions:

• Enzymatic depolymerization using microbial polyesterases is a promising approach for sustainable plastic recycling.
• Further research into novel enzyme discovery and protein engineering is vital for a circular plastics economy.