Discovery of a novel native bacterium of Providencia sp. with high biosorption and oxidation ability of manganese for bioleaching of heavy metal contaminated soils
Discovery of a novel native bacterium of Providencia sp. with high biosorption and oxidation ability of manganese for bioleaching of heavy metal contaminated soils
复制标题
发现一种新的原生细菌普罗维登斯菌。
DOI：
10.1016/j.chemosphere.2019.125039
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发表时间：
2020-02-01
期刊：
影响因子：
8.8
通讯作者：
Tang, Jianxin
中科院分区：
文献类型：
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作者：
Li, Ding;Li, Ruyi;Tang, Jianxin
重金属污染土壤的去除是一个长期的挑战性问题，对全球经济、环境和人类健康具有重要意义。海洋和淡水来源的锰氧化细菌被认为是有前途的生物修复剂的环境应用。然而，土壤来源的Mn（II）氧化细菌的实际应用仍有待开发污染土壤修复。本研究对一株新的土壤源细菌的Mn（II）吸附/氧化机理及其对土壤中重金属的生物淋滤效率进行了详细的研究。首先，我们从重金属污染土壤中发现、分离并鉴定了一株新的高Mn（II）耐受细菌Providencia sp. LLDRA 6。其次，菌株LLDRA 6在水溶液中表现出其高Mn（II）生物吸附能力。因此，LLDRA 6对Mn（II）的吸附被大量证明是（i）Mn（II）在细胞表面上沉淀、（ii）Mn（II）在细胞表面上氧化成BioMnO（x）和（iii）不溶性MnCO 3在细胞内积累的协同效应。最后，提出了利用普罗维登菌LLDRA 6及其所形成的生物MnO（x）进行联合生物淋滤，以开发一种潜在的环境友好且经济有效的修复严重重金属污染土壤的技术。生物淋滤试验表明，普罗威登斯菌LLDRA 6与生物MnO（x）的组合对重金属Pb具有良好的去除效果（81.72%），铬（88.29%），镉（90.34%），铜（91.25%），Mn（56.13%），Zn（59.83%），与单独使用普罗威登斯菌LLDRA 6相比，去除率提高了1.68-26.4%。此外，细菌浸出液还促进了土壤中残留态金属向易迁移态金属的转化。研究结果表明，菌株LLDRA 6对重金属污染土壤具有较强的吸附能力，为环境生物修复提供了良好的生物吸附剂。(C)2019爱思唯尔有限公司版权所有。
Heavy metal removal from contaminated soils is a long-term challenging problem important for global economics, environment, and human health. Marine and freshwater-originated Mn(II)-oxidizing bacteria are considered as the promising bioremediation agents for environmental applications. However, practical application of soil-originated Mn(II)-oxidizing bacteria remains to be developed for contaminated soil remediation. In this work, the Mn(II) biosorption/oxidation mechanism of a new soil-originated bacterium and its bioleaching efficiency of heavy metals from soils was studied in detail. First, we found, isolated and identified a new highly Mn(II)-tolerant bacterial strain Providencia sp. LLDRA6 from heavy metal-contaminated soils. Next, strain LLDRA6 demonstrated its high Mn(II) biosorption capacity in aqueous solution. Then, Mn(II) adsorption by LLDRA6 was largely proven to be a synergistic effect of (i) Mn(II) precipitation on the cell surface, (ii) oxidation of Mn(II) into BioMnO(x) on the cell surface, and (iii) intracellular accumulation of insoluble MnCO3. Finally, combination bioleaching by the bacterium of Providencia sp. LLDRA6 and its formed BioMnO(x) was proposed to develop a potential environment-friendly and cost-effective technique to remediate severely heavy metal-contaminated soils. The bioleaching tests demonstrated that the combination of Providencia sp. LLDRA6 and BioMnO(x) exhibited an excellent removal efficiency for heavy metals of Pb (81.72%), Cr (88.29%), Cd (90.34%), Cu (91.25%), Mn (56.13%), and Zn (59.83%) from contaminated soils, resulting in an increase of removal efficiency in the range of 1.68-26.4% compared to Providencia sp. LLDRA6 alone. Moreover, the bacterial leachate facilitated the residual fraction of metals to transform into the easily migratory fractions in soils. These findings have demonstrated that strain LLDRA6 has high adsorption ability to remove heavy metals from contaminated soils, thus providing a promising bio-adsorbent for environmental bioremediation. (C) 2019 Elsevier Ltd. All rights reserved.