To increase the platinum adsorption capacity of Escherichia coli (E. coli) biomass, we fused EC20 protein to the E. coli cell surface using an InaKN-based display system, which is the N-terminal region of ice nucleation protein that can be employed as a cell surface display motif. The media and culture conditions were optimized for EC20 (a phytochelatin analogue with 20 repeating units of glutamate and cysteine) expression and Pt (IV) biosorption. Furthermore, the adsorption process was elucidated from aspect of adsorption kinetics and equilibrium, and the characterization of blank and Pt-loaded cells were analyzed using SEM, AFM, TEM, FT-IR and XPS. Our study demonstrated that E. coli strain, which had InaKN-EC20 protein expressed on the cell surface, showed a great enhancement in Pt (IV) adsorption under optimized condition when comparing with that of original E. coli strain. The SEM-EDX analysis revealed that the cellular morphology has been changed in Pt-loaded cells, and the weight percent of platinum in the surface of E.coli increased substantially after displaying EC20 protein. Furthermore, intracellular platinum accumulation was detected in Pt-loaded EC20 cells since a clear peak of platinum exhibited, implying that cytoplasmic EC20 protein might also contribute to platinum accumulation. FTIR analysis revealed that the predominant functional groups in platinum adsorption were amine, carboxyl and phosphate groups.

为了增加大肠杆菌（E. coli）生物质的铂吸附能力，我们使用基于InaKN的展示系统将EC20蛋白融合到大肠杆菌细胞表面，该系统是可以使用的冰核蛋白的N端区域。作为细胞表面展示的主题。培养基和培养条件针对EC20（具有20个重复单元的谷氨酸和半胱氨酸的植物螯合素类似物）的表达和Pt（IV）的生物吸附进行了优化。此外，从吸附动力学和平衡方面阐明了吸附过程，并使用SEM，AFM，TEM，FT-IR和XPS分析了空白和负载Pt的电池的特性。我们的研究表明，大肠杆菌与原始大肠杆菌菌株相比，在优化的条件下，在细胞表面表达InaKN-EC20蛋白的大肠杆菌菌株显示出对Pt（IV）吸附的极大增强。SEM-EDX分析表明，载有Pt的细胞的细胞形态已发生变化，展示EC20蛋白后，大肠杆菌表面铂的重量百分比显着增加。此外，由于显示了清晰的铂峰，因此在装载Pt的EC20细胞中检测到细胞内铂积累，这表明细胞质EC20蛋白也可能有助于铂积累。FTIR分析表明，铂吸附中主要的官能团是胺，羧基和磷酸基。