Bacterial biodegradation of synthetic plastics: a review

Plastics are synthetic polymers that are reluctant to degradation. Therefore, their unlimited use has caused environmental problems. The reuse, reduce, and recycle methodology can solve these problems. However, this method is not efficient for mixed plastic wastes. As a result, more efficient and eco-friendly methods are necessary to remove these pollutants.

Biodegradation is a more effective and operative method for resolving the global plastic waste problem. This method is defined as breaking down chemical compounds by the enzymes released by organisms. Bacteria are among the plastic-degrading organisms. Plastic biodegradation by bacteria occurs in four successive steps: biodeterioration, depolymerization, assimilation, and mineralization. Plastic biodegradation by these microorganisms includes different enzymatic reactions, converting synthetic plastics into simple mineral materials. These enzymes are part of metabolic pathways that use these polymers as primary substrates. Several factors, including the chemical structure of synthetic plastics, can affect their biodegradation efficacy.

Although it is a promising solution for a global problem, bacterial biodegradation of synthetic plastics suffers from limitations such as slowness. The aim of the present study is to examine different aspects of bacterial biodegradation of synthetic plastics. These include the introduction of important plastic-degrading bacterial genera and enzymes involved in this biodegradation process. Additionally, metabolic pathways of synthetic plastic biodegradation, factors controlling this process, and limitations of this eco-friendly solution are examined.