Nanoplastic Generation from Secondary PE Microplastics: Microorganism-Induced Fragmentation

Abstract

Concern regarding the pollution of the marine environment with plastics has been rising in recent years. Plastic waste residing in and interacting with the environment fragments into secondary particles in the micro- and nanoscale, whose negative impacts on the environment are even greater than those of the parent items. In this work, secondary high density polyethylene (HDPE) and low density polyethylene (LDPE) microplastics were produced by irradiation of virgin films following mechanical fragmentation. The fragments with size ranging from 250 μm to 2 mm were selected for subsequent microcosm experiments. Incubation for 120 days in seawater inoculated with two marine communities, Agios, acclimatized to utilizing plastics as a carbon source, and Souda, as was collected at the Souda bay (Crete, Greece), resulted in biofilm formation by polyethylene (PE) degraders. Monthly FTIR (Fourier-transform infrared spectroscopy) examination of the samples revealed changes in the chemical structure of the surface of the polymers. Dynamic light scattering (DLS) was employed and nano- and microparticles with sizes in the range between 56 nm and 4.5 μm were detected in the seawater of inoculated microcosms. It was thus demonstrated that weathered plastics particles can biodeteriorate and biofragment as a result of biofilm attachment, resulting in the production of nanoplastics due to microbial activity.

Engineering a microbiosphere to clean up the ocean – inspiration from the plastisphere

“…antioxidants, fillers, flame retardants, UV-light stabilisers, impact modifiers, heat stabilisers, would also need to be remediated to reduce their cellular toxic effects (Hahladakis et al, 2018). This also applies to organic pollutants adsorbed to the plastic waste (Karkanorachaki et al, 2022). Several microbial species have been reported in the literature that are capable of degrading plastic additives, e.g.…”

Micro- and nanoplastics effects in a multiple stressed marine environment

“…The occurrence of MPs and the predicted co-occurrence of NPs in the environment indicates that organisms can be exposed to a continuum of complex mixtures of MNPs, with further interaction with multiple stressors. The environmental observation of NPs still remains challenging ( Paul-Pont et al, 2018 ), but in laboratory settings the fragmentation of MPs to NPs has been established via weathering phenomena ( Mattsson et al, 2021 ), and via interactions with biota such as digestive fragmentation from krill ( Dawson et al, 2018 ) or microorganisminduced fragmentation ( Karkanorachaki et al, 2022 ). This fragmentation is expected to occur in the environment ( Paul-Pont et al, 2018 ), and the number of NPs is predicted to be higher than that of MPs ( Lenz et al, 2016 ).…”

Microplastic emerging pollutants – impact on microbiological diversity, diarrhea, antibiotic resistance, and bioremediation

“…Mechanical abrasion and ultraviolet radiation exposure under simulated coastal conditions produced millions of secondary MPs. 5 MPs (MP) are found in marine and freshwater habitats, such as beaches, seawater, marine sediments, surface water, and silt from lakes and rivers. 6 Estuaries and rivers are the sources of most MP in the ocean and coastal waters.…”