Exploration on the bioreduction mechanisms of Cr(VI) and Hg(II) by a newly isolated bacterial strain Pseudomonas umsongensis CY-1.
Exploration on the bioreduction mechanisms of Cr(VI) and Hg(II) by a newly isolated bacterial strain Pseudomonas umsongensis CY-1.
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DOI：
10.1016/j.ecoenv.2020.110850
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发表时间：
2020-06
影响因子：
6.8
通讯作者：
Yang Yao;L. Hu;Shuzhen Li;Q. Zeng;H. Zhong;Zhiguo He
中科院分区：
文献类型：
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作者：
Yang Yao;L. Hu;Shuzhen Li;Q. Zeng;H. Zhong;Zhiguo He
尽管利用微生物修复Cr（VI）和Hg（II）污染已取得了显著进展，但利用同一种微生物菌株同时还原Cr（VI）和Hg（II）的研究尚未见报道。在这项研究中，新分离的假单胞菌umsongensisCY-1铬污染的土壤中，并表现出修复潜力的Cr（VI）和Hg（II）污染。当Cr（VI）和Hg（II）的初始浓度为5 mg/L时，Cr（VI）和Hg（II）的去除率最高，分别为93.9%和82.8%。通过静息细胞和热处理静息细胞去除的比较表明，P. umsongensisCY-1在Tris-HCl缓冲液（pH7.0）中对Cr（VI）和Hg（II）的去除主要是通过还原作用而不是吸附作用。通过比较不同细胞组分对Cr（VI）和Hg（II）的还原率，发现Cr（VI）和Hg（II）的还原主要发生在P.透射电镜（TEM）分析进一步证实了它们的存在。X射线光电子能谱分析表明，Cr（VI）和Hg（II）的还原产物主要分别以Cr（III）和Hg（0）的形式存在。本研究的结果将为多种重金属污染场地的生物修复提供进一步的指导。
Despite of significant progress in remediation of Cr(VI) or Hg(II) pollution by microorganisms, study on the reduction of both Cr(VI) and Hg(II) by the same microbial strain was not reported so far, which is actually important for bioremediation of contaminated sites with multiple heavy metals. In this study,Pseudomonas umsongensisCY-1 was newly isolated from chromium-contaminated soil and showed remediation potentials for both Cr(VI) and Hg(II) pollution. The highest Cr(VI) (93.9%) and Hg(II) (82.8%) reduction rates were obtained at the initial concentration of 5 mg/L. Comparison between removal by resting cells and heat-treated resting cells demonstrated thatP. umsongensisCY-1 removed Cr(VI) and Hg(II) from Tris-HCl buffer (pH 7.0) mainly through reduction instead of adsorption. By comparing the Cr(VI) and Hg(II) reduction rates of different cellular fractions, it was found that Cr(VI) and Hg(II) reductions mainly happened in the cytoplasm ofP. umsongensisCY-1, which were further demonstrated by Transmission electron microscopy (TEM) analysis. Furthermore, analysis of X-ray photoelectron spectroscopy demonstrated that the reduction products of Cr(VI) and Hg(II) were mainly in the form of Cr(III) and Hg (0), respectively. The findings in this study will provide a guide for further insights in the bioremediation of contaminated sites with multiple heavy metals.