Heavy metal contamination is a global threat with far-reaching effects for both human health and the environment. Biological agents, such as plants and microorganisms, provide uncomplicated and eco-friendly ways of removing toxic metals; thus, they are regarded as successful and alternative tools. In this study, we evaluated the ability of Streptomyces NJ10 (SN10), an oxalotrophic bacterium with outstanding oxalate metabolizing potential, to convert toxic lead oxalate (PbOx) into lead carbonate (PbCO3). SN10 was therefore used to determine the reduction of toxicity of Chinese leafy vegetables grown in the presence of PbOx in the soil. When compared to control, SN10 treated pots showed improved plant growth characters, i.e. shoot length (5.85 ± 0.56 cm), average leaf area (5.5 ± 0.44 cm2) and root length (7.2 ± 0.45 cm), as established by the plant growth attributes and the results obtained are statistically significant (at P ≤ 0.05) (for a period of 30 days). Furthermore, X-ray diffraction (XRD) and Scanning Electronic Microscopy-Energy-Dispersive X-ray Spectroscopy (SEM-EDS) studies revealed that PbOx was successfully transformed into a less toxic, water-insoluble precipitate of Pb-bearing carbonate, Phosgenite. The results provided a new idea for the biotransformation and toxicity mitigation of Pb contamination in soil.
Supplementary information: The online version contains supplementary material available at 10.1007/s13205-022-03353-6.
Keywords: Chinese leafy vegetables; Heavy metal toxicity; Lead carbonate; Oxalotrophic Streptomyces.
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