分离自铜矿山尾矿区的铁还原菌nju-T1菌株:菌种鉴定及其还原Fe^(3+)的最适条件

A Study on the Ferric Reduction Microorganism nju-T1 Isolated from Shizishan Tailings, Tongling, Anhui Province

对安徽铜陵狮子山杨山冲尾矿库采集的酸矿水(AMD)及表层尾砂样品,采用FeTo选择性培养基,利用Overlay分离技术,获得了一株具有铁还原功能的细菌nju-T1。形态观察、生理生化鉴定以及16SrRNA基因序列同源性分析结果表明,该菌株属于Acidithiobacillus属。平板培养和液体培养实验证明,nju-T1具有在有氧条件下还原Fe3+的功能。nju-T1在pH为4.5,温度为30℃条件下生长较好,最适还原Fe3+浓度为5mmol/L,还原铁的作用位点可能是位于细胞外膜上。nju-T1能还原Fe3+,为铁氧化菌提供了初始能源Fe2+,同时维持了整个酸矿水系统的铁平衡。研究nju-T1的还原机理,不仅拓宽了对铁还原菌通常只能在兼性厌氧或厌氧条件下才能生长的认识,更对研究整个酸性矿山环境的形成、发展机理以及治理有着重要意义。

A new iron reduction strain, named nju-T1, was isolated from acid mine drainage （AMD） and surface tailings samples from Yangchongshan tailings zone, Shizishan, Tongling, Anhui province, with FeTo selective medium and overlay culture technology. The morphological, physiological and biochemical research and phylogenetic analysis based on the 16S rRNA gene sequence showed that the strain belongs to Acidithiobacillus . It was found that nju-T1 could reduce Fe 3＋ under aerobic conditions with plate and liquid cultural tests. The pH range for growth was pH 2.0-6.0, with optimum growth at pH 4.5, optimum growth temperature at 30 ℃ and optimum ferric iron concentration at 5 mmol/L. It was inferred that the reduction sites may be located on the cell outer membrane. AMD and tailings were controlled by the dynamic balance between the microbial functional groups and surroundings. The nju-T1 reduced ferric to ferrous, which provided initial energy to ferrous-oxidizing bacteria and maintained the Fe recycle and stability of acid mine environment. The research on mechanism of ferric reduction with nju-T1 not only broadens the knowledge about ferric reduction bacteria mainly growing under the anaerobic condition, but also has great significance inunderstanding the formation of acid mine environment, its development mechanism and its further environmental treatment.