(中南大學(xué) 資源加工與生物工程學(xué)院， 長沙 410083)
摘 要: 為了找、到能從高硅含量鋁土礦中脫硅的細(xì)菌，利用無氮鋁硅酸鹽礦物培養(yǎng)基對菜園土、 生物鉀肥、 鋁土礦等材料進行了硅酸鹽細(xì)菌的分離， 篩選到一株編號為GSY—5↑#的產(chǎn)莢膜芽孢桿菌。 通過對該細(xì)菌的形態(tài)、 生理生化等表型特征以及固體、液體培養(yǎng)條件研究， 發(fā)現(xiàn)該細(xì)菌菌體大小為（1~1.2）μm×（4~7）μm， 莢膜呈橢圓形， 大小為（5~15）μm×（10~30）μm；培養(yǎng)后期產(chǎn)生芽孢， 芽孢呈橢圓形， 大小為（1.5~1.7）μm×（3~4）μm。 顯微鏡下觀察細(xì)菌不運動， 沒有觀察到鞭毛。 該菌生長最適pH為7.3~8.4， 最適生長溫度為30℃。 在礦物鹽固體培養(yǎng)基上生長良好， 具有較強的固氮能力。 通過比較該菌與膠質(zhì)芽孢桿菌模式菌株的生理生化特征，可認(rèn)為GSY—5#菌株是硅酸鹽細(xì)菌膠質(zhì)芽孢桿菌。 使用GSY—5#菌株對5種含有不同鋁硅酸鹽礦物的鋁土礦進行了生物脫硅研究， 浸出條件為pH 7.2， 30℃， 200r/min， 礦漿含量5%， 浸出7d。 5種礦樣的A/S分別從4.58， 6.74， 6.03， 5.09， 2.93提高到5.88， 8.45， 8.55， 6.79， 13.54， 表明該株硅酸鹽細(xì)菌具有一定的脫硅能力。
關(guān)鍵字: 硅酸鹽細(xì)菌； 膠質(zhì)芽孢桿菌； 篩選； 模式菌株； 表型特征； 鋁土礦； 脫硅
（ School of Resources Processing and Bioengineering,
Central South University, Changsha 410083, China）
Abstract: In order to obtain some strains of bacterium which may liberate silicate from bauxite with a high Si content, some strains of bacterium were isolated from materials such as garden soil, biological fertilizer and bauxite mineral using nitrogen media. The phenotype characteristics such as morphology, physiology and biochemical tests show that GSY—5# bacteria belong to Bacillus sp because they are rod shaped and can produce oval endospore. The sizes of bacteria and endospore are (1-1.2)μm×(4-7)μm and (1.5-1.7)μm×(3-4)μm, respectively. The cultivating conditions of GSY—5# on solid media and in liquid media were identified. The results show that GSY—5# grows best within pH range of 7.3-8.4, and the optimum temperature for the growth is 30℃.The microorganism can fix nitrogen because it grows very well on solid nitrogen-free mineral media and show apparent capsule. It can produce a rich variety of exo-polysacchoride in liquid nitrogen-free media. In comparison of characteristics of GSY—5# bacteria with those of mold strain of Bacillus mucilaginosus, GSY—5# bacteria are a strain of Bacillus mucilaginosus. In this experiment five bauxite samples containing aluminosilicates as impurities were leached with silicate bacteria GSY—5# at pH 7.2, 30℃, 200r/min, for 7 days, and the ratio of Al2O3 to SiO2(A/S) in samples is increased from 4.58 to 5.88, from 6.74 to 8.45, from 6.03 to 8.55, from 5.09 to 6.79 and from 2.93 to 13.54, respectively. The leaching results indicate that leaching with silicate bacteria is useful in the improvement of low-grade high-SiO2 bauxite.
Key words: silicate bacteria; bacillus mucilaginosus; screening; mold strain; phenotype characteristics; bauxite
