硅酸盐细菌代谢产物对硅酸盐矿物的浸溶作用研究

Leaching Effects of Metabolites of Silicate Bacterium on Silicate Minerals

研究发现,硅酸盐细菌JXF菌株在含有石英粉的培养基中能合成有机酸、氨基酸、多糖等各种代谢产物并分泌释放到发酵液中。随着发酵时间的延长,发酵液中4种有机酸(草酸、柠檬酸、酒石酸、苹果酸)含量逐渐降低,说明细菌又以它们为营养物质进行生长繁殖;在菌种的不同发酵期,合成氨基酸的种类不同,在无氮或含石英粉的培养基中,有利于细菌大量合成多糖类物质。摇瓶试验表明,有机酸、氨基酸、多糖均具有破坏高岭石晶格结构的能力而释放出其中的铝、硅,原因是这些有机物具有络合矿物中各种金属离子的有机基团并有一定的酸溶作用。试验还表明,各种代谢产物在浸出硅酸盐矿物中具有协同作用,三者的混合物的浸矿效果明显好于它们各自对矿物的作用效果。

The results of researches showed that the strain JXF was able to produce a variety of metabolites such as organic acids, amino acids and polysaccharides in the culture solution with quartz powders and release them to the ferment solution. With the increase of ferment time the contents of four organic acids （oxalic ,tartaric ,citric and malic acids） decreased. It indicated that the bacteria increased with the organic acids as nurture. Ferment experiments showed that strain JXF produced different metabolites with different contents in different phases of bacteria ferment. The bacteria can produce lots of polysaccharides in the culture solution with quartz powders or without nitrogen. The flask tests showed that all these metabolites can destroy the crystal structure of kaolinite, resulting in the release of SiO2 and Al2O3 from kaolinite. It is because that these organics have groups which can react with metallic ions in minerals. These metabolites can cooperate in the leaching of silicate ores such as kaolinite. The leaching results of the mixture of the three kinds of metabolites are obviously better than those of single metabolite.