| Autor: |
Li, Jiayao1 (AUTHOR), Tang, Chen1 (AUTHOR), Zhang, Min2 (AUTHOR), Fan, Chun1 (AUTHOR), Guo, Dongbei1 (AUTHOR), An, Qiuying1 (AUTHOR), Wang, Guangshun1 (AUTHOR), Xu, Hao1 (AUTHOR), Li, Yi1 (AUTHOR), Zhang, Wei1 (AUTHOR), Chen, Xiaoxuan1 (AUTHOR), Zhao, Ran1 (AUTHOR) zhaoran@xmu.edu.cn |
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| Zdroj: |
Ecotoxicology & Environmental Safety. Dec2021, Vol. 225, pN.PAG-N.PAG. 1p. |
| Abstrakt: |
Serious hexavalent chromium [Cr(VI)] pollution has continuously threatened ecological security and public health. Microorganism-assisted remediation technology has strong potential in the treatment of environmental Cr(VI) pollution due to its advantages of high efficiency, low cost, and low secondary pollution. Sporosarcina saromensis M52, a strain with strong Cr(VI) removal ability, isolated from coastal intertidal zone was used in this study. Scanning electron microscopy coupled with energy dispersive X-ray analysis indicated M52 was relatively stable under Cr(VI) stress and trace amount of Cr deposited on the cell surface. X-ray photoelectron spectroscopy and X-ray diffraction analyses exhibited M52 could reduce Cr(VI) into Cr(III). Fourier transform infrared spectroscopy showed the bacterial surface was mainly consisted of polysaccharides, phosphate groups, carboxyl groups, amide II (NH/CN) groups, alkyl groups, and hydroxyl groups, while functional groups involving in Cr(VI) bio-reduction were not detected. According to these characterization analyses, the removal of Cr(VI) was primarily depended on bio-reduction, instead of bio-adsorption by M52. Genome analyses further indicated the probable mechanisms of bio-reduction, including the active efflux of Cr(VI) by chromate transporter ChrA, enzymatic redox reactions mediated by reductases, DNA-repaired proteases ability to minimize the ROS damage, and the formation of specific cell components to minimize the biofilm injuries caused by Cr(VI). These studies provided a theoretical basis which was useful for Cr(VI) remediation, especially in terms of increasing its effectiveness. M52 realized the bioremediation of Cr(VI) majorly through bio-reduction, including Cr(VI) efflux, chromate reduction, DNA repair, and the formation of specific cell components, instead of bio-adsorption. [Display omitted] • Characterization analysis (SEM-EDX, FTIR, XRD and XPS) confirmed that M52 could reduce Cr(VI) to Cr(III) with poor biosorption capacity. • Genomic analysis showed that a large number of genes in M52 were involved in encoding Cr(VI) metabolic and transport related proteins. • M52 could reduce Cr(VI) mainly intracellularly. [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
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