Shi, Y.; Ma, R.; Qi, L.; Tan, X.; Chen, L.; Wang, Y.; Huang, K.; Suo, Z.; Li, Y.; Chen, H.; Chen, Z.; Chen, X.; Li, W.; Zhen, K.

Nickel contamination poses increasing environmental and industrial challenges, demanding effective and sustainable remediation strategies. Here, we present a modular synthetic biology approach to engineer Escherichia coli for efficient nickel enrichment, resilience in toxic environments, intracellular biomineralization, and hydrogen-based co-culture stability. Our system comprises four functional modules: (1) a nickel enrichment module, in which the fusion protein NixA-F1v outperformed existing uptake systems, and a mutant repressor RcnRC35L enhanced retention by suppressing nickel efflux; (2) a survival module where heterologous expression of Helicobacter pylori Hpn conferred tolerance to high nickel concentrations, and YejM increased phage resistance; (3) a nickel microparticle module enabling intracellular bioconversion of nickel into detectable microparticles even without engineered uptake proteins; and (4) a hydrogen supply module supporting co-culture stability through E. coli-cyanobacteria adhesion for sustained hydrogen production. These modules were experimentally validated through comparative uptake assays, survival profiling, and microscopy-based particle detection. Our findings demonstrate a customizable and integrative microbial platform for metal bioremediation and biosensing, with potential applications in environmental engineering and industrial waste treatment.