Microbially induced carbonate precipitation (MICP) is a technique used extensively to address heavy metal pollution but its micro-dynamic process remains rarely explored. In this study, A novel Cd-tolerant ureolytic bacterium DL-1 (Pseudochrobactrum sp.) was used to study the micro-dynamic process. With conditions optimized by response surface methodology, the removal efficiency of Cd²⁺ could achieve 99.89%. Three components were separated and characterized in the reaction mixture of Cd²⁺ removal by MICP. The quantitative-dynamic distribution of Cd²⁺ in different components was revealed. Five synergistic effects for Cd²⁺ removal were found, including co-precipitation, adsorption by precipitation, crystal precipitation on the cell surface, intracellular accumulation and extracellular chemisorption. Importantly, during Cd²⁺ removal by MICP, the phenomenon that crystalline nanoparticles adhere to the cell surface, but without any micrometer-sized precipitation encapsulated bacterial cells was observed. This indicated that the previously studied model of bacterial cells as nucleation sites for metal cation precipitation and crystal growth is oversimplified. Our findings provided valuable insights into the mechanism of heavy metals removal by MICP, and a more straightforward method for studying biomineralization-related dynamic process.

微生物诱导碳酸盐沉淀 (MICP) 是一种广泛用于解决重金属污染的技术，但其微动态过程仍然很少被探索。在这项研究中，一种新的耐镉尿素分解细菌DL-1（Pseudochrobactrum sp.）被用来研究微观动力学过程。^{通过响应面法优化条件，Cd 2+}去除率可达99.89%。在MICP去除Cd ²⁺的反应混合物中分离和表征了三种组分。揭示了不同组分中Cd ²⁺的定量动态分布。^{Cd 2+}的五种协同效应发现包括共沉淀、沉淀吸附、细胞表面晶体沉淀、细胞内积累和细胞外化学吸附。重要的是，在MICP去除Cd ²⁺的过程中，观察到结晶纳米颗粒粘附在细胞表面，但没有任何微米级沉淀包裹细菌细胞的现象。这表明先前研究的细菌细胞作为金属阳离子沉淀和晶体生长的成核位点的模型过于简单。我们的研究结果为 MICP 去除重金属的机制提供了有价值的见解，并为研究生物矿化相关的动态过程提供了一种更直接的方法。