矿物环境对硅酸盐细菌的铝土矿浸矿脱硅作用的影响

Effects of mineral environments on desilicon from bauxite by silicate bacteria

选用一株从铝土矿样表面分离的胶质芽孢杆菌,研究了在不同矿物环境中该菌种的生理生化特性及对铝土矿的浸矿脱硅效果。研究结果表明:不同矿物环境培养菌的生理生化特性有一定的差别,且对相应矿物中的主要元素具有一定的溶解作用;钾长石、高岭石与橄榄石培养菌的铝土矿浸出上清液中SiO2的含量要比其它矿物培养菌的高0.5～1.0倍,同时,它们在发酵过程中产酸与产多糖量要比其它矿物培养菌高,形成了明显的矿物-菌体复合体;不同矿物培养菌对铝土矿中各元素的生物催化活性具有一定的选择性,橄榄石、方解石、赤铁矿培养菌分别对铝土矿中的镁、钙、铁元素的溶解作用明显要比其它矿物培养菌强。分析认为,菌种在不同矿物培养环境中可以产生特定元素的诱导酶系,根据铝土矿中杂质元素种类,可以选择相应的矿物培养菌或者混合菌种对铝土矿进行生物浸出,以提高铝土矿的品质。

A strain of silicate bacteria screened from the surface of bauxite was chosen to carry on its physio-biochemical characteristics in different mineral culture media and desilicon from bauxite.The results showed that the strains of enrichment cultivated in different mineral media have different physio-biochemical characters,and can release major elements containing in corresponding minerals.The strains cultivated in orthoclase,kaolinite and olivine media have stronger abilities of desilicon from bauxite,the SiO2 content intheir supernatants are 0.5—1.0 times higher than the strains cultivated in other minerals.In addition,and the above strains produced more acids and polysaccharides,forming obvious bacterial-mineral complexes in the process of bauxite bioleaching.Strains cultivated in different minerals have selectivity over bio-catalytic.The strains cultivated in olivine,calcite and hematite media have better ability in dissolving,Mg and Fe.The results showed that the strains cultivated in different minerals are able to produce certain inducible enzymes for specific elements.Therefore,certain mineral training strains or mixed mineral training strains can be chosen to decompose bauxite depending on the composition of bauxite.