生物浸出过程中黄铁矿表面胞外多聚物和铁离子的分布及含量变化
Distribution and content changes of extracellular polymeric substance and iron ions on the pyrite surface during bioleaching
曾伟民 1刘志茹 2廖婉晴 2成金菊 2吴学玲 1邱冠周 1申丽1
作者信息
- 1. School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China;Key Laboratory of Biometallurgy of Ministry of Education(Central South University),Changsha 410083,China
- 2. School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China
- 折叠
摘要
微生物-矿物界面是生物浸出的主要生化反应场所,界面作用机制是阐明微生物浸矿行为的关键.本文通过Acidithiobacillus caldus、Leptospirillum ferriphilum和Sulfobacillus thermosulfidooxidans三种中度嗜热混合菌对黄铁矿颗粒和黄铁矿切片分别进行了生物浸出实验和生物膜的定殖实验,采用高选择性和高灵敏性的金属荧光探针结合激光共聚焦显微镜、扫描电子显微镜和物理提取法对生物浸出过程中界面胞外聚合物(EPS)和铁离子的分布及其含量变化进行了研究.结果表明,EPS平铺在黄铁矿切片表面形成的片状生物膜主要在生物浸出的前期和中期形成,在第15天浓度达17.21 mg/g,主要成分为胞外蛋白.在生物浸出前期,黄铁矿表面主要以Fe2+(0.75 mg/g)为主,Fe3+仅有0.08 mg/g,随着浸出时间的增加,大量的Fe3+(11.97 mg/g)富集在微生物-矿物界面.
Abstract
Microbial-mineral interface is the main biochemical reaction place of bioleaching, and the mechanism of interface interaction is the key to elucidating the behavior of microbial leaching. In this paper, bioleaching experiments and biofilm colonization experiments of pyrite grains and pyrite slices were conducted by three moderately thermophilic mixed bacteria, Acidithiobacillus caldus, Leptospirillum ferriphilum and Sulfobacillus thermosulfidooxidans, respectively. The distribution and content changes of interfacial extracellular polymeric substance (EPS) and iron ions during bioleaching were evaluated based on a highly selective and sensitive metal fluorescence probe combined with confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and physical extraction methods. The results show that EPS was laid flat on the surface of pyrite slices to form sheet biofilms, mainly in the early and middle stages of bioleaching, reaching 17.21 mg/g on the 15th day, and the main component was extracellular protein. At the early stage of bioleaching, the surface of pyrite was mainly dominated by Fe2+ of 0.75 mg/g, while Fe3+ was only 0.08 mg/g. With the increase of leaching time, a large amount of Fe3+ (11.97 mg/g) was enriched at the microbe-mineral interface.
关键词
生物浸出/黄铁矿/中度嗜热菌/界面/生物膜/金属离子/胞外多聚物/激光共聚焦Key words
bioleaching/pyrite/mixed culture/interface/biofilm/metal ion/extracellular polymeric substance/confocal laser scanning microscopy引用本文复制引用
基金项目
National Natural Science Foundation of China(51934009)
National Natural Science Foundation of China(52074353)
Zijin Mining State Key Laboratory of Biometallurgy Open Fund,China(20225199K001)
出版年
2023
NETL
NSTL
维普
万方数据