Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.
Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.
Sci Total Environ. 2023 Dec 15;904:167001. doi: 10.1016/j.scitotenv.2023.167001. Epub 2023 Sep 11.
As a toxic element of global concern, the elevated concentration of antimony (Sb) in the environment has attracted increasing attention. Microorganisms have been reported as important driving forces for Sb transformation. Iron (Fe) is the most important metal associated element of Sb, however, how Fe-bearing minerals affect the biological transformation of Sb is still unclear. In this study, the effects of Fe-bearing minerals on biological Sb(V) reduction were investigated by employing a marine Shewanella sp. CNZ-1 (CNZ-1). Our results showed that the presence of hematite, magnetite and ferrihydrite (1 g/L) resulted in a decrease in Sb(III) concentration of ~19-31 % compared to the Fe(III)-minerals free system. The calculated Sb(V) reduction rates are 0.0256 (R 0.71), 0.0389 (R 0.87), 0.0299 (R 0.96) and 0.0428 (R 0.95) h in the hematite-, magnetite-, ferrihydrite-supplemented and Fe(III)-minerals free systems, respectively. The cube-shaped SbO was characterized as a reductive product by using XRD, XPS, FTIR, TG and SEM approaches. Differential proteomic analysis showed that flagellar protein, cytochrome c, electron transfer flavoprotein, nitrate reductase and polysulfide reductase (up-regulation >1.5-fold, p value <0.05) were supposed to be included in the electron transport pathway of Sb(V) reduction by strain CNZ-1, and the key role of nitrate reductases was further highlighted during this reaction process based on the RT-qPCR and confirmatory experiments. Overall, these findings are beneficial to understand the environmental fate of Sb in the presence of Fe-bearing minerals and provide guidance in developing the bacteria/enzyme-mediated control strategy for Sb pollution.
作为一种全球性关注的有毒元素，环境中锑（Sb）的浓度升高引起了越来越多的关注。微生物已被报道为 Sb 转化的重要驱动力。铁（Fe）是与 Sb 关系最密切的金属相关元素，然而，含铁矿物如何影响 Sb 的生物转化仍不清楚。在这项研究中，采用海洋希瓦氏菌 CNZ-1（CNZ-1）研究了含铁矿物对生物 Sb(V)还原的影响。我们的结果表明，与无 Fe(III)-矿物系统相比，赤铁矿、磁铁矿和水铁矿（1 g/L）的存在导致 Sb(III)浓度降低约 19-31%。在赤铁矿、磁铁矿、水铁矿补充和无 Fe(III)-矿物系统中，Sb(V)还原速率分别为 0.0256 (R 0.71)、0.0389 (R 0.87)、0.0299 (R 0.96)和 0.0428 (R 0.95) h。通过 XRD、XPS、FTIR、TG 和 SEM 方法，将特征为立方 SbO 的 Sb 确定为还原产物。差异蛋白质组学分析表明，鞭毛蛋白、细胞色素 c、电子传递黄素蛋白、硝酸盐还原酶和多硫化物还原酶（上调>1.5 倍，p 值<0.05）被认为包含在菌株 CNZ-1 还原 Sb(V)的电子传递途径中，并且硝酸盐还原酶在该反应过程中的关键作用基于 RT-qPCR 和验证实验得到进一步强调。总的来说，这些发现有助于了解 Sb 在含铁矿物存在下的环境归宿，并为开发细菌/酶介导的 Sb 污染控制策略提供指导。
