Bioimmobilization of lead in phosphate mining wasteland by isolated strain Citrobacter farmeri CFI-01. (15th August 2022)

• Record Type: Journal Article
• Authors: Li, Yizhong; Guo, Shuyu; Zheng, Yunting; Yu, Junxia; Chi, Ruan; Xiao, Chunqiao
• Is Part Of: Environmental pollution. Volume 307(2022)
• Publication Date: 2022-08-15
• Subjects: Phosphate rock -- Pb contamination -- Metagenomic analysis -- Microbial remediation -- Phosphate solubilizing bacteria; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2022.119485
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Industrial phosphate rock (PR) treatment has introduced lead (Pb) contamination into phosphate mining wasteland, causing serious contamination. Although bioremediation is considered an effective method and studies have investigated the bioimmobilization of Pb contamination in phosphate mining wasteland by phosphate-solubilizing bacteria (PSB), the bioimmobilization mechanism remains unclear. In this study, a strain Citrobacter farmeri CFI-01 with phosphate-solubilizing and Pb-tolerant abilities was isolated from a phosphate mining wasteland. Liquid culture experiments showed that the maximum content of soluble phosphate and the percentage amount of Pb immobilized after 14 days were 351.5 mg/L and 98.18%, respectively, with a decrease in pH. Soil experiments showed that CFI-01 had reasonable bioimmobilization ability, and the percentage amount of Pb immobilized was increased by 7.790% and 22.18% in the groups inoculated with CFI-01, respectively, compared with that of the groups not inoculated with CFI-01. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses showed that the immobilization of Pb was also ascribed to changes in the functional groups (e.g., hydroxyl and carboxyl groups) and the formation of lead phosphate sediments. Finally, the results of the metagenomic analysis indicated that changes in the microbial community structure, enrichment of related functional abundances (e.g., metal metabolism, carbohydrate metabolism, and amino acid metabolism functions), and activation of functional genes (e.g., zntA, smtB, cadC, ATOX1, smtA, and ATX1) could help immobilize soil Pb contamination and explore the mechanism of bacterial bioimmobilization in Pb-contaminated soil. This study provides insights for exploring the immobilization mechanism of Pb contamination in phosphate mining wasteland using PSB, which has significance for further research. Graphical abstract: Image 1 Highlights: Native strain had effective abilities of PR solubilization and Pb tolerance. Citrobacter farmeri CFI-01 can immobilize Pb in phosphate mining wasteland. The mechanism of remediation of Pb contamination by PSB is bioimmobilization. Microbial species and functional abundances changed through metagenomic analysis. Abstract : Capsule: The native strain Citrobacter farmeri CFI-01 effectively reduced Pb contamination in a phosphate mining wasteland.