硅酸盐细菌代谢产物对不同结构硅酸盐矿物风化作用的影响

The Influence of Silicate Bacterial Metabolites on Weathering of Silicate Minerals with Different Crystal Structures

选用一株硅酸盐细菌,采用摇瓶发酵培养,对比分析不同结构硅酸盐矿物刺激与促进细菌产代谢产物的差异;采用摇瓶浸矿试验,研究细菌代谢产物及细菌对石英、斜长石与高岭石的风化分解作用。结果表明,硅酸盐矿物可促进细菌产草酸、酒石酸、苹果酸等有机酸、氨基酸与多糖,同时可刺激细菌代谢产生特定的柠檬酸与氨基酸,高岭石对细菌代谢产有机酸与多糖促进作用最强,斜长石对细菌代谢产生氨基酸促进作用最明显;各代谢产物均对硅酸盐矿物具有一定的风化分解作用,其中多糖对矿物分解作用最强,混合代谢产物对矿物具有更强的风化作用;具层状结构的高岭石较架状结构的斜长石更易被细菌及代谢产物所风化分解;3种代谢产物的混合物在风化矿物过程中具有明显协同作用;细菌对矿物分解作用明显较混合代谢产物强,表明细菌对矿物风化分解作用是生物物理及化学等多种因素共同作用的结果。

The difference of bacterial metabolites secreted by the selected silicate bacterium in differrent media containing silicate minerals with different structures was investigated in shake flasks. The weathering of quartz, orthoclase and kaolinite by microbial metabolites and bacteria was researched by shake flask bioleaching experiments. The results show the tested silicate minerals can promote the strain to secrete organic acids （oxalate, tartaric acid and malic acid）, amino acids and polysaccharide, and stimulate the strain to produce citric acid and some specific amino acids. Kaolinite promotes the strain to secrete organic acids and polysaccharide more obviously, and orthoclase stimulates the strain to produce amino acids higher effectively than other tested silicate minerals. Amino acid mixture, organic acid mixture and polysaccharide can weather tested silicate minerals, and polysaccharide has the strongest mineral weathering ability. The complex of all metabolites can decompose minerals more effectively than amino acid mixture, organic acid mixture and polysaccharide alone. Different metabolites have a certain synergistic effect on weathering anorthose. Kaolinite with layer structure are more easily decomposed than orthoclase with framework structure by bacteria. Bacteria can more effectively weather minerals in comparison with the metabolite complex, the result shows that silicate bacteria can weather silicate minerals at the integrated operation of many microbial, physical and chemical factors.