Isolation of a strain of Acidithiobacillus caldus and its role in bioleaching of chalcopyrite
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- 作者：Qiu Guan Zhou ; Fu Bo ; Zhou Hong Bo ; Liu Xi ; Gao Jian ; Liu Fei Fei and Chen Xin Hua
- 关键词：Acidithiobacillus caldus ; Bioleaching ; Chalcopyrite ; Isolation ; 16S rRNA
- 刊名：World Journal of Microbiology and Biotechnology
- 出版时间：September, 2007
- 出版年：2007
- 期刊代码：121_09593993
- 类别：bio
- 卷：23
- 期：9
- 页码：1217-1225
- 数据来源：sp
摘要
A moderately thermophilic and acidophilic sulfur-oxidizing bacterium named S2, was isolated from coal heap drainage. The bacterium was motile, Gram-negative, rod-shaped, measured 0.4 to 0.6 by 1 to 2 μm, and grew optimally at 42–45掳C and an initial pH of 2.5. The strain S2 grew autotrophically by using elemental sulfur, sodium thiosulfate and potassium tetrathionate as energy sources. The strain did not use organic matter and inorganic minerals including ferrous sulfate, pyrite and chalcopyrite as energy sources. The morphological, biochemical, physiological characterization and analysis based on 16S rRNA gene sequence indicated that the strain S2 is most closely related to Acidithiobacillus caldus (>99%similarity in gene sequence). The combination of the strain S2 with Leptospirillum ferriphilum or Acidithiobacillus ferrooxidans in chalcopyrite bioleaching improved the copper-leaching efficiency. Scanning electron microscope (SEM) analysis revealed that the chalcopyrite surface in a mixed culture of Leptospirillum ferriphilum and Acidithiobacillus caldus was heavily etched. The energy dispersive X-ray (EDX) analysis indicated that Acidithiobacillus caldus has the potential role to enhance the recovery of copper from chalcopyrite by oxidizing the sulfur formed during the bioleaching progress.