中文摘要：

从土壤中筛选到一株产絮凝剂的硅酸盐菌株B12。对其絮凝剂产生条件进行优化，并考查其絮凝特性。以质量浓度为8g／L的葡萄糖和0．15g／L的（NH4）2SO4作为碳源和氮源，调节初始pH值至6．9，在温度为31℃、转速为150r／min的摇床中培养72h后，菌株的絮凝活性最高，絮凝率可达93．6％。絮凝剂特性研究表明：供氧可提高细菌的生长量，但不利于絮凝剂的生成。分段培养有利于提高絮凝率。该菌起絮凝作用的主要是其胞外代谢物，其适用pH值范围广，为0．5～12，絮凝率大于90％；B12菌生物絮凝剂稳定性好，与其他无机絮凝剂相比，其絮凝活效果好、无毒、无二次污染，在矿浆固液分离及矿物废水处理方面有着广阔的应用前景。

英文摘要：

A flocculant-producing silicate strain, B12, was isolated from soil. Its flocculant producing conditions and flocculation characteristics were studied. The results show that, adding 8 g/L glucose and 0.15 g/L （NH4）2504 as the source of carbon and nitrogen, adjusting the initial pH value at 6.9, culturing 72 h at 31 ~C and the shaking speed of 150 r/min, the highest flocculating rate reaches 93.6%. Providing oxygen can enhance the bacterium growth rate, but will be disadvantageous to product flocculant. B12 is cultured in sections, which is benefit for promoting the flocculating rate. The extracellular metabolites of B12 strain mainly takes the flocculant, and could apply in pH range of 0.5-12 with highly stability, and the flocculant rate is above 90%. Compared with other inorganic flocculants, the bioflocculant is high effective, non-toxic and with no secondary pollution, and it will have a good prospect of application in the solid-liquid separation and mineral pulp wastewater treatment.