Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610213, China.
Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610213, China; Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xi'an, Shanxi Province 710064, China.
J Hazard Mater. 2024 Jul 15;473:134600. doi: 10.1016/j.jhazmat.2024.134600. Epub 2024 May 12.
Microbiologically induced calcite precipitation (MICP), as a newly developing bioremediation technology, could redeem heavy metal contamination in diverse scenarios. In this study, MICP bacterium Sporosarcina ureilytica ML-2 was employed to suppress the pollution of Pb, Cd and Zn in municipal sludge nutrient soil. After MICP remediation, the exchangeable Cd and Zn in sludge nutrient soil were correspondingly reduced by 31.02 % and 6.09 %, while the carbonate-bound Pb, Cd and Zn as well as the residual fractions were increased by 16.12 %, 6.63 %, 13.09 % and 6.10 %, 45.70 %, 3.86 %, respectively. In addition, the extractable Pb, Cd and Zn either by diethylenetriaminepentaacetic acid (DTPA) or toxicity characteristic leaching procedure (TCLP) in sludge nutrient soil were significantly reduced. These results demonstrated that the bio-calcite generated via MICP helped to immobilize heavy metals. Furthermore, MICP treatment improved the abundance of functional microorganisms related to urea cycle, while reduced the overall abundance of metal resistance genes (MRGs) and antibiotic resistance genes (ARGs). This work confirmed the feasibility of MICP in remediation of heavy metal in sludge nutrient soil, which expanded the application field of MICP and provided a promising way for heavy metal pollution management.
微生物诱导碳酸钙沉淀（MICP）作为一种新兴的生物修复技术，可以在多种情况下修复重金属污染。本研究采用微生物诱导碳酸钙沉淀细菌 Sporosarcina ureilytica ML-2 抑制城市污泥营养土中 Pb、Cd 和 Zn 的污染。MICP 修复后，污泥营养土中可交换态 Cd 和 Zn 分别减少了 31.02%和 6.09%，而碳酸盐结合态 Pb、Cd 和 Zn 以及残渣态分别增加了 16.12%、6.63%、13.09%和 6.10%、45.70%、3.86%。此外，通过二乙三胺五乙酸（DTPA）或毒性特征浸出程序（TCLP）提取的污泥营养土中可提取的 Pb、Cd 和 Zn 也显著减少。这些结果表明，MICP 产生的生物碳酸钙有助于固定重金属。此外，MICP 处理提高了与尿素循环相关的功能微生物的丰度，而降低了金属抗性基因（MRGs）和抗生素抗性基因（ARGs）的总体丰度。这项工作证实了 MICP 在修复污泥营养土中重金属的可行性，扩展了 MICP 的应用领域，为重金属污染治理提供了一种有前途的方法。
