Microplastics (MPs), defined as plastic particles smaller than 5 mm, are persistent and widespread in both aquatic and terrestrial ecosystems owing to the mismanagement of plastic waste [1, 2]. These particles undergo aging through environmental weathering, increasing their toxicity and capacity to adsorb pollutants [3, 4]. These particles can cause physical stress, inflammation, oxidative damage, and immune responses, potentially contributing to diseases such as cancer, metabolic disorders, and neurodevelopmental conditions [5]. In response to growing concerns, the revised EU Urban Wastewater Treatment Directive highlights the need to reduce the release of target micropollutants, including MPs, into the environment [6]. In this study, the potential of biodegradation using the enzyme laccase was investigated as an eco-friendly and sustainable approach for their removal from wastewater. According to previous studies, laccase can break polymer bonds, potentially reducing environmental persistence and toxicity [7]. Three of the most common types of MPs were tested: low-density polyethylene (LDPE, 300 and 600 µm), polyethylene terephthalate (PET, 300 µm), and polyamide nylon 6 (PA6, 20 µm). Laccase concentrations ranging from 50 to 200 U/L were applied over a 7-day incubation period, and enzyme activity was determined using the ABTS oxidation method. MP samples were analyzed using FTIR and Raman spectroscopy to assess their structural modifications. The results indicated potential surface alterations evidenced by increased fluorescence in the Raman spectra; however, further optimization is required to enhance the degradation of specific functional groups and improve biodegradation efficiency.
References
- Gao, Y., et al. Sci Total Environ 2024, 957: 177427
- Wang, L., et al. Chemosphere 2023, 315: 137744
- Martinho, S.D., et al. Toxic Effects of Micro‐ and Nanoplastics: Environment, Food and Human Health, Wiley, 2024
- Binda, G., et al. TrAC Trends in Analytical Chemistry 2024, 172
- Molina, E. and S. Benede. Front Nutr 2022, 9: 910094
- Directive (EU) 2024/3019 of the European Parliament and of the Council of 27 November 2024 concerning urban wastewater treatment (recast)
- Ramamurthy, K., et al. Int J Biol Macromol 2024, 276,133971
