Microbe-assisted Enzymatic Degradation of Microplastic

Anthropogenic activities have critically contributed to the pollution of air, water, and soil using various organic and inorganic contaminants. Plastic is one such primary recalcitrant pollutant that is prepared using coal, crude oil, and other non-renewable sources of energy. Additionally, the production of plastics around the globe has increased significantly within the last decade. Plastics take several years to degrade during which smaller-sized plastic particles termed microplastics are formed. The microplastics thus formed can further cause hazardous impacts on the flora and fauna as well as act as carriers for other contaminants. Hence, various methods are explored for the effective degradation of microplastics. Microbial enzyme-mediated microplastic degradation is one such potentially useful method that is discussed in detail in this chapter. Various microbial enzymes are reported to exhibit polyethylene, polyethylene terephthalate, polystyrene, and polypropylene degrading activities. Bacterial strains such as Bacillus sp., Clostridium thermocellum, Enterobacter asburiae, Exiguobacterium sp., Lysinibacillus sp., and Rhodococcus ruber produce various enzymes that can effectively degrade microplastics. Furthermore, certain fungal species such as Fusarium solani, Penicillium chrysogenum, Purpureocillium lilacinum, Rhizopus oryzae, Scedosporium aurantiacum, and Trichoderma brevicompactum can also produce manganese peroxidases which have microplastic degrading activity. Therefore, further investigation into the mechanism of microbial enzyme-mediated microplastic degradation can provide important insights into the feasibility of its large-scale application for in-situ microplastic remediation.