Biological Degradation of Plastics and Microplastics: A Recent Perspective on Associated Mechanisms and Influencing Factors

Abstract

Plastic and microplastic pollution has caused a great deal of ecological problems because of its persistence and potential adverse effects on human health. The degradation of plastics through biological processes is of great significance for ecological health, therefore, the feasibility of plastic degradation by microorganisms has attracted a lot of attention. This study comprises a preliminary discussion on the biodegradation mechanism and the advantages and roles of different bacterial enzymes, such as PET hydrolase and PCL-cutinase, in the degradation of different polymers, such as PET and PCL, respectively. With a particular focus on their modes of action and potential enzymatic mechanisms, this review sums up studies on the biological degradation of plastics and microplastics related to mechanisms and influencing factors, along with their enzymes in enhancing the degradation of synthetic plastics in the process. In addition, biodegradation of plastic is also affected by plastic additives and plasticizers. Plasticizers and additives in the composition of plastics can cause harmful impacts. To further improve the degradation efficiency of polymers, various pretreatments to improve the efficiency of biodegradation, which can cause a significant reduction in toxic plastic pollution, were also preliminarily discussed here. The existing research and data show a large number of microorganisms involved in plastic biodegradation, though their specific mechanisms have not been thoroughly explored yet. Therefore, there is a significant potential for employing various bacterial strains for efficient degradation of plastics to improve human health and safety.

Freshwater plastisphere: a review on biodiversity, risks, and biodegradation potential with implications for the aquatic ecosystem health

“…More recently, the focus has shifted from studying specific strains or enzymes to examining the plastisphere community as a whole “degradation unit” ( Jacquin et al, 2019 ; Yuan et al, 2020 ; Eronen-Rasimus et al, 2022 ; Joshi et al, 2022 ; Taipale et al, 2022 ; Cai et al, 2023 ; Maheswaran et al, 2023 ; Miao et al, 2023 ; Niu et al, 2023 ; Vaksmaa et al, 2023 ; Yu et al, 2023 ; Zhu et al, 2023 ). Various key microbial taxa can cooperate and show enzymatic potential for polymer biodegradation ( Li K. et al, 2023 ; Li W. et al, 2023 ; Miao et al, 2023 ), also promoting changes in surface material properties, including chemical composition, morphology roughness, formation of holes and cracks, and weight loss.…”

Recent advances in microbial and enzymatic engineering for the biodegradation of micro- and nanoplastics

“…However, there is still much to learn about the exact process by which these enzymes degrade microplastics, and further research is needed. 152 Furthermore, there have been notable advancements in the field of microbial enzymes that possess the ability to break down lignin polymers containing oxidative C–C bonds. Notable examples include manganese peroxidase, lignin peroxidase, and laccase.…”

Microplastic pollution in riparian soils of the rapidly growing city of Thimphu, Bhutan

“…In addition, the action of UV radiation and photodegradation, combined with mechanical strain from water movement, wind, and humans, on plastic waste leads to the formation of more MPs (Hebner & Maurer-Jones, 2020; Lin et al, 2020; X. . Numerous soil microorganisms also facilitate the biodegradation of plastic waste, which accelerates the decomposition and build-up of MPs in the environment (Cai et al, 2023). Secondary sources of MPs derived from the breakdown of plastic waste can be supplemented by primary sources of speci cally manufactured MPs.…”