Plastics: Environmental and Biotechnological Perspectives on Microbial Degradation

Area of Science:

• Environmental microbiology
• Biotechnology
• Polymer science

Background:

• Millions of tons of plastic waste accumulate annually due to poor recycling and low circular use.
• Plastic pollution adversely affects ecosystems, with microplastics posing health concerns.
• Microbial degradation of plastics is an emerging area of research.

Purpose of the Study:

• To review current knowledge on microbial plastic degradation.
• To identify limitations in existing microbial degradation capabilities.
• To highlight the need for novel biocatalysts for widespread plastic types.

Main Methods:

• Literature review of studies on microbial plastic degradation.
• Analysis of enzymes and microorganisms targeting specific plastic polymers.
• Identification of knowledge gaps in degrading major plastic types.

Main Results:

• Enzymes currently exist that degrade polyethylene terephthalate (PET) and ester-based polyurethane (PUR).
• Known PET- and PUR-degrading enzymes and microbes exhibit moderate turnover rates.
• No enzymes are currently known to degrade major polymers like polystyrene, polyamide, PVC, polypropylene, ether-based polyurethane, and polyethylene.

Conclusions:

• Significant research is required to discover novel enzymes and microorganisms capable of degrading the most abundant plastic polymers.
• Exploring metagenomes of non-cultivated microorganisms and dark matter proteins can yield new biocatalysts.
• Developing effective biocatalysts is crucial for rapid degradation, recycling, and value-added utilization of most plastics.