Microbial Degradation of Plastics and Approaches to Make it More Efficient

Abstract

Abstract— The growing worldwide production of synthetic plastics leads to increased amounts of plastic pollution. Even though microbial degradation of plastics is known to be a very slow process, this capacity has been found in many bacteria, including invertebrate symbionts, and microscopic fungi. Research in this field has been mostly focused on microbial degradation of polyethylene, polystyrene, and polyethylene terephthalate (PET). Quite an arsenal of different methods is available today for detecting processes of plastic degradation and measuring their rates. Given the lack of generally accepted protocols, it is difficult to compare results presented by different authors. PET degradation by recombinant hydrolases from thermophilic actinobacteria happens to be the most efficient among the currently known plastic degradation processes. Various approaches to accelerating microbial plastic degradation are also discussed.

Microbial Enzyme Biotechnology to Reach Plastic Waste Circularity: Current Status, Problems and Perspectives

“…Moreover, some of these plastics (PE, PP) are completely crystalline, preventing enzymes from accessing the potential attack sites. Therefore, a multistep reaction catalyzed by a combination of abiotic pretreatments and different types of oxidative enzymes has been proposed [ 171 ].…”

“…The latter can produce intermediate acid oligomers that are intracellularly taken-up by microorganisms and further metabolized [ 176 , 177 ]. Several microbial strains capable of degrading PE with this proposed system have been reported, including the gut microbiota of invertebrates [ 106 , 171 ]; animal phenol oxidase (EC 1.14.15.3) enzymes contained in the saliva of wax worm ( Galleria mellonella ) larvae were also demonstrated to be involved in the oxidative degradation of PE [ 107 ]. No system studied to date can achieve complete biodegradation without abiotic intervention.…”

Merging Plastics, Microbes, and Enzymes: Highlights from an International Workshop

“…Moreover, there is an urgent need to determine how to accurately evaluate the biodegradation of plastics. These methods can be focused on the changes in the physicochemical and mechanical properties after modification/disassembly of polymers (e.g., gravimetric measurements, Fourier transform infrared spectroscopy, atomic force microscopy, and/or thermogravimetric analysis), on the quantification of oligomer/monomer generation, on the metabolic products of microbial respiration (e.g., CO 2 ), on the monitoring of oxygen consumption (e.g., using an OxiTop BOD system) ( 35 ), or a combination of the above ( 36 ). The detection of products after a biodegradation process can easily be performed (e.g., using high-performance liquid chromatography) for some hydrolyzable plastics, but in the case of polyolefins, specific and advanced techniques are required ( 37 ).…”

Biotechnological methods to remove microplastics: a review

“…Microplastic treatments enabled by the action of microorganisms such as algae, fungi, and bacteria are considered attracting tools for cost-effective and eco-friendly degradation approaches. While research papers and reviews have recently been published on the microorganism-mediated degradation and remediation strategies (Chen et al 2022 ; Bahtt et al 2021 ; Qin et al 2021 ; Kotova et al 2021 ; Cholewinski et al 2022 ), only few articles have addressed plastic degradation focusing on the use of modern biotechnological methods in the enhancement of microplastic degradation and there remains a lack of knowledge with respect to biotechnological interventions for microplastic removal (Danso et al 2019 ; Patrício Silva et al 2021 ). Therefore, it is crucial to summarize and analyze the current state of knowledge to determine microplastic degradation by microorganism, as well as to promote a better understanding of how modern biotechnological methods can be enabled to manage and degrade microplastics.…”