Szczyrba Elżbieta, Pokynbroda Tetiana, Gąszczak Agnieszka, Koretska Nataliia, Tistechok Stepan, Roman Ivan, Gromyko Oleksandr
Institute of Chemical Engineering, Polish Academy of Sciences, Bałtycka 5, 44-100 Gliwice, Poland.
Department of Physical Chemistry of Fossil Fuels of the Institute of Physical-Organic Chemistry and Coal Chemistry named after L. M. Lytvynenko of the National Academy of Sciences of Ukraine, Naukova Str., 79060 Lviv, Ukraine.
Polymers (Basel). 2025 Aug 27;17(17):2318. doi: 10.3390/polym17172318.
The growing concern over the long-term persistence of plastic waste has driven research into biological methods of breaking down polymers. This study investigated a process that combines physicochemical pretreatment and biodegradation of low-density polyethylene (LDPE) using bacterial strains isolated from commercial compost. Four bacterial strains were genetically identified and classified as . Exposure of LDPE to these selected strains resulted in a measurable reduction in polymer sample weight, accompanied by alterations in surface hydrophobicity. Furthermore, the chemical modifications at the films' surfaces were confirmed by the spectra obtained by Fourier transform infrared spectroscopy (FTIR). The microbial colonisation of plastic surfaces plays a key role in the overall biodegradation process. The formation of a biofilm and the subsequent morphological changes on the LDPE surface were revealed by scanning electron microscopy (SEM). The modification of the polyethylene surface by nitric acid treatment was found to be a promising strategy for enhancing the LDPE degradation. The acid-treated films exhibited the greatest weight loss, the greatest increase in carbonyl index values, and the greatest change in hydrophobicity following microbial exposure. Moreover, it was found that biodegradation under these conditions resulted in the lowest levels of phytotoxic byproducts. The transformation of polyethylene surface properties-from hydrophobic to hydrophilic-combined with the presence of oxidized functional groups made it easier for microorganisms to degrade LDPE.
对塑料垃圾长期存在的日益关注推动了对聚合物生物降解方法的研究。本研究调查了一种结合物理化学预处理和使用从商业堆肥中分离出的细菌菌株对低密度聚乙烯（LDPE）进行生物降解的过程。对四种细菌菌株进行了基因鉴定并分类为 。将LDPE暴露于这些选定的菌株导致聚合物样品重量有可测量的减少，并伴随着表面疏水性的改变。此外，通过傅里叶变换红外光谱（FTIR）获得的光谱证实了薄膜表面的化学修饰。塑料表面的微生物定殖在整个生物降解过程中起着关键作用。通过扫描电子显微镜（SEM）揭示了LDPE表面生物膜的形成以及随后的形态变化。发现用硝酸处理对聚乙烯表面进行改性是增强LDPE降解的一种有前景的策略。经酸处理的薄膜在微生物暴露后表现出最大的重量损失、最大的羰基指数值增加以及最大的疏水性变化。此外，发现在这些条件下的生物降解产生的植物毒性副产物水平最低。聚乙烯表面性质从疏水性到亲水性的转变，结合氧化官能团的存在，使得微生物更容易降解LDPE。
