Department of Plankton and Microbial Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Stechlin 16775, Germany; Institute of Biochemistry and Biology, Potsdam University, Potsdam 14469, Germany.
Department of Plankton and Microbial Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Stechlin 16775, Germany.
Sci Total Environ. 2024 Jul 15;934:173188. doi: 10.1016/j.scitotenv.2024.173188. Epub 2024 May 11.
Plastic polymers are present in most aspects of routine daily life. Their increasing leakage into the environment poses a threat to environmental, animal, and human health. These polymers are often resistant to microbial degradation and are predicted to remain in the environment for tens to hundreds of years. Fungi have been shown to degrade complex polymers and are considered good candidates for bioremediation (biological pollutant reduction) of plastics. Therefore, we screened 18 selected fungal strains for their ability to degrade polyurethane (PU), polyethylene (PE), and tire rubber. As a proxy for plastic polymer mineralization, we quantified O consumption and CO production in an enclosed biodegradation system providing plastic as the sole carbon source. In contrast to most studies we demonstrated that the tested fungi attach to, and colonize the different plastic polymers without any pretreatment of the plastics and in the absence of sugars, which were suggested essential for priming the degradation process. Functional polymer groups identified by Fourier-transform infrared spectroscopy (FTIR), and changes in fungal morphology as seen in light and scanning electron microscopy (SEM) were used as indicators of fungal adaptation to growth on PU as a substrate. Thereby, SEM analysis revealed new morphological structures and deformation of the cell wall of several fungal strains when colonizing PU and utilizing this plastic polymer for cell growth. Strains of Fusarium, Penicillium, Botryotinia cinerea EN41, and Trichoderma demonstrated a high potential to degrade PU, rubber, and PE. Growing on PU, over 90 % of the O was consumed in <14 days with 300-500 ppm of CO generated in parallel. Our study highlights a high bioremediation potential of some fungal strains to efficiently degrade plastic polymers, largely dependent on plastic type.
塑料聚合物存在于日常生活的大多数方面。它们越来越多地泄漏到环境中，对环境、动物和人类健康构成威胁。这些聚合物通常抵抗微生物降解，并预计将在环境中存在数十到数百年。真菌已被证明可以降解复杂的聚合物，被认为是塑料生物修复（生物污染物减少）的良好候选物。因此，我们筛选了 18 株真菌，以评估它们降解聚氨酯（PU）、聚乙烯（PE）和轮胎橡胶的能力。作为塑料聚合物矿化的替代物，我们在一个封闭的生物降解系统中量化了 O 的消耗和 CO 的产生，该系统提供塑料作为唯一的碳源。与大多数研究相反，我们证明了测试的真菌附着在不同的塑料聚合物上，并在没有任何塑料预处理且没有糖的情况下殖民化，糖被认为是启动降解过程的必要条件。傅里叶变换红外光谱（FTIR）鉴定的功能聚合物基团，以及在光和扫描电子显微镜（SEM）中观察到的真菌形态变化，被用作真菌适应以 PU 作为基质生长的指标。因此，SEM 分析揭示了当几株真菌定植 PU 并利用这种塑料聚合物进行细胞生长时，细胞壁的新形态结构和变形。腐霉属、青霉属、Botryotinia cinerea EN41 和木霉属的菌株显示出降解 PU、橡胶和 PE 的高潜力。在 PU 上生长时，<14 天内消耗了超过 90%的 O，并同时产生了 300-500ppm 的 CO。我们的研究强调了一些真菌菌株具有高效降解塑料聚合物的高生物修复潜力，这在很大程度上取决于塑料类型。
