Recovery of Manganese from Mine Drainage using Biomineralization

利用从北海道南部春季分离到的氧化锰菌和氧化锰细菌圆盘细毛藻(ATCC 43162和51168)，在中性pH值条件下对溶液中的Mn(II)离子进行了去除。用X射线衍射仪、X射线荧光光电子能谱、X射线光电子能谱和扫描电子显微镜对沉积的锰进行了表征。结果表明，氧化锰细菌(ATCC 51168)能氧化24ppm的Mn(II)离子，并且由于保持了细菌的鞘结构，在静态培养条件下保持了比摇床培养更高的氧化锰活性。已建立的ATCC细菌的培养基组分不能直接用于分离的真菌对Mn(II)的氧化，因此对其进行了修改。通过将介质中有机碳源浓度降低1/10，该真菌在一周内从溶液中去除了50ppm以上的Mn(II)离子。经鉴定该真菌为Phoma sp.该真菌有利于氧化锰沉淀物中微粒的积累，经X射线衍射仪、X射线荧光光电子能谱和X射线光电子能谱分析表明，生物矿化沉淀物为非晶态锰氧化物。

Manganese-oxidizing fungus, isolated from spring in south of Hokkaido, and manganese-oxidizing bacteria Leptothrix discophora (ATCC 43162 and 51168) were applied to removal of Mn(II) ions from solutions at neutral pHs. The manganese deposits were characterized by XRD, XRF, XPS and FE-SEM.It was found that manganese-oxidizing bacteria, L. discophora (ATCC 51168), oxidized 24 ppm of Mn(II) ions, and that the bacteria kept higher manganese-oxidizing activity in static culture than in shaking culture, because of keeping the sheath structure in the bacteria. The established medium compositions for the ATCC bacteria could not be directly applied to the oxidation of Mn(II) ions for the isolated fungus, therefore, modified. By reduction of 1/10 in concentrations of organic carbon sources in the medium, the fungus oxidized to remove over 50 ppm of Mn(II) ions from the solutions within one week. The fungus was identified to be Phoma sp. The fungus was useful to accumulate fine particles of the oxidized Mn sediments within itself.The bio-mineralized sediments were characterized to be non-crystalline Mn oxides by XRD, XRF, and XPS.