Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.
Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.
J Basic Microbiol. 2020 Jan;60(1):37-46. doi: 10.1002/jobm.201900415. Epub 2019 Nov 7.
Geobacter metallireducens GS15, a model of dissimilatory iron-reducing bacteria, is the key regulator in biogeochemical iron cycling. How the emerging contaminant microplastics involved in the iron cycling are driven by microbes on the microscale remains unknown. Hence, the influences of two typical microplastics, polybutylene terephthalate-hexane acid (PBAT) and polyvinyl chloride (PVC), were explored on the activity of G. metallireducens GS15 with ferrihydrite or ferric citrate as the respective electron acceptors. The results showed that the iron (II) contents in PBAT- and PVC-treatment groups were 16.79 and 6.81 mM, respectively, at the end of the experiment. Compared with the PBAT-treatment group, scanning electron microscopy and energy dispersive spectrometery revealed that merely a small amount of iron-containing products covered the surface of PVC. Moreover, PBAT and PVC could both retard the electroactivity of G. metallireducens GS15 at the beginning of microbial fuel cell operation. On the basis of the results above, microplastic PVC might exhibit potential inhibition of the iron cycling process driven by G. metallireducens GS15 with ferrihydrite as the terminal electron acceptor. This study extended our understanding of the influence of the microplastics PBAT and PVC on microbially mediated biogeochemical iron cycling. The findings might have an important implication on the biogeochemical elements cycling in the ecosystem with the involvement of emerging contaminant microplastics.
产亚铁还原菌 GS15 是异化还原铁细菌的模式种，是生物地球化学铁循环的关键调节因子。在微尺度上，参与铁循环的新兴污染物微塑料是如何被微生物驱动的，目前尚不清楚。因此，本研究探索了两种典型的微塑料（聚对苯二甲酸丁二醇酯-己二酸酯（PBAT）和聚氯乙烯（PVC））对以水铁矿或柠檬酸铁作为各自电子受体的 GS15 产亚铁还原菌活性的影响。结果表明，实验结束时，PBAT 和 PVC 处理组中的铁（II）含量分别为 16.79 和 6.81mM。与 PBAT 处理组相比，扫描电子显微镜和能谱分析表明，只有少量含铁产物覆盖在 PVC 表面。此外，PBAT 和 PVC 均可在微生物燃料电池运行初期抑制 GS15 产亚铁还原菌的电化学活性。基于上述结果，微塑料 PVC 可能对以水铁矿为末端电子受体的 GS15 驱动的铁循环过程表现出潜在的抑制作用。本研究扩展了我们对微塑料 PBAT 和 PVC 对微生物介导的生物地球化学铁循环影响的认识。这些发现可能对涉及新兴污染物微塑料的生态系统中生物地球化学元素循环具有重要意义。
