中文摘要：

利用铝硅酸盐矿物为能源的硅酸盐细菌选择性分离培养基，对从鄱阳湖地区不同性质土壤中筛选出了18株拟溶硅菌种进行实验。通过对其产酸、产多糖、形成细菌-矿物复合体与溶硅能力的测定，定向筛选出P04与P17两株环状芽孢杆菌，并以中国普通微生物菌种保藏中心环状芽孢杆菌CGMCCl．0153（编号为P19）（Bacillus circulans）为参照菌株，对其表型形态、生理生化特性及脱硅效果进行了研究。结果表明：与其它菌种比较，这两株菌种具有较强的产酸、产多糖与溶硅能力，在培养基中能形成明显的细菌-矿物复合体；通过与模式菌株的表型形态与生理生化特征及16SrRNA基因鉴定结果比较，可认为P04与P17是环状芽孢杆菌；在实验条件下，P04，P17与P19对铝土矿均有一定的脱硅能力，浸矿12d后，浸出上清液中SiO：最大含量分别为54．26，42．78，47．98mg／L，铝土矿的A／S从浸出前的5．17分别提高到10．99，7．61和8．90。表明具有较强产酸、产多糖能力并能形成明显细菌-矿物复合体的环状芽孢杆菌的脱硅能力较强。

英文摘要：

Eighteen strains of similar silicate bacteria were isolated from different soil samples taken from Poyang lake area in Jiangxi Province in China by using selective medium based on aluminosilicate minerals as energy source. Two strains of P04 and P17, which have higher abilities of producing acids, polysaccharides, and desilicon than those of other strains, were picked out by measuring pHs, viscosities, and observing morphologies of bacteria-mineral complexes. Physiological and biochemical characters and silicon releasing capacity of the two strains were tested by setting Bacillus circullans CGMCC1.0153（strain code： P19） from China General Microbiological Culture Collection Center as the modal strain. The results show that the strains P04 and P17 can secrete more acids and polysaecharides, and release more silicon from minerals than other strains in the culture media, and can form obviously bacteria-mineral complexes. Strains P04 and P17 belonged to Bacillus circullans in comparison of their characteristics with those of the modal strain. Strains P04, P17 and P19 can decompose silicate minerals in bauxite and release silicon from them. The maximum concentrations of SiO2 of supernatants in the media are 49.69, 32.78, 37.98 rag/L, respectively after bioleaching for 12 days, and the ratios of A1203 to SiO2（A/S） of bauxite increased from 5.17 to 10.99, 7.61,8.90 respectively. It is concluded that the silicate bacterium with higher abilities of producing acids and polysaccharides and forming obviously bacteria-mineral complexes has higher desilicon abilitiy.