Chang Jifei, Liang Danhui, Gao Yan, Sun Yitong, Wang Xin, Ren Nan-Qi, Li Nan
Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300350, China.
Water Res. 2025 Jan 1;268(Pt A):122583. doi: 10.1016/j.watres.2024.122583. Epub 2024 Oct 6.
Acting as both terminal and conductor of extracellular electron transfer (EET), little studies were focused on how nano-magnetite participated in the dissimilated iron reduction (DIR), especially the synthesis of vivianite, which was the typical DIR products from sewage. In this study, nano-magnetite was confirmed to enhance DIR of ferrihydrite and akaganeite for vivianite recovery from sewage. Nano-magnetite incorporation enriched Comamonas and Geobacter in sewage, and microbial protein content was increased by 123 % and 57 % in ferrihydrite and akaganeite batches, respectively. In Geobacter sulfurreducens PCA pure culture, vivianite yield was promoted by 21 % and 37 % in ferrihydrite and akaganeite batches in the presence of nano-magnetite, respectively. Due to its nanoscale size and superior electrical conductivity, nano-magnetite embedded in the gaps formed by the microorganisms and electron acceptor, and architected coherent conductive pathways to promote EET. Simultaneously, the addition of nano-magnetite stimulated the secretion of proteins, polysaccharides, and humic acids in the extracellular polymeric substances. Nano-magnetite addition structured an enormous and compact electron transfer network, thus enhanced DIR and vivianite formation. Our study proposed a new strategy to promote iron-reduction-coupled phosphorus recovery with natural DIR products, and provided theoretical support for clarifying the interaction between minerals and microorganisms.
作为细胞外电子转移（EET）的终端和导体，关于纳米磁铁矿如何参与异化铁还原（DIR），尤其是参与蓝铁矿（污水中典型的DIR产物）的合成的研究很少。在本研究中，已证实纳米磁铁矿可增强水铁矿和针铁矿的DIR，以从污水中回收蓝铁矿。纳米磁铁矿的加入使污水中的丛毛单胞菌属和地杆菌属富集，在水铁矿和针铁矿批次中，微生物蛋白质含量分别增加了123%和57%。在嗜硫地杆菌PCA纯培养物中，在存在纳米磁铁矿的情况下，水铁矿和针铁矿批次中蓝铁矿的产量分别提高了21%和37%。由于其纳米级尺寸和优异的导电性，纳米磁铁矿嵌入微生物和电子受体形成的间隙中，并构建连贯的导电途径以促进EET。同时，纳米磁铁矿的添加刺激了细胞外聚合物中蛋白质、多糖和腐殖酸的分泌。纳米磁铁矿的添加构建了一个巨大而紧凑的电子转移网络，从而增强了DIR和蓝铁矿的形成。我们的研究提出了一种利用天然DIR产物促进铁还原耦合磷回收的新策略，并为阐明矿物与微生物之间的相互作用提供了理论支持。
