Effects of Chloride Acclimation on Iron Oxyhydroxides and Cell Morphology during Cultivation of Acidithiobacillus ferrooxidans
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- 作者：Huixin Xiong ; Rong Guo
- 刊名：Environmental Science & Technology
- 出版年：2011
- 出版时间：January 1, 2011
- 年：2011
- 卷：45
- 期：1
- 页码：235-240
- 全文大小：351K
- 年卷期：v.45,no.1(January 1, 2011)
- ISSN：1520-5851
文摘
Iron oxyhydroxides as the efficient scavengers for heavy metals have been extensively investigated in iron-rich acid sulfate waters in the presence of Acidithiobacillus ferrooxidans (A. ferrooxidans, an especially important chemolithoautotroph for bioleaching and desulfurization of coal). In this study, we observed the morphology and elemental composition of cells in stationary phase and examined the dynamic variation of iron oxyhydroxides produced in cultures of A. ferrooxidans incubated in modified 9K medium initially including 0.15 M of ferrous iron, in the absence/presence of 0.2 M of chloride (NaCl/FeCl2). Results showed that chloride acclimation had little effect on cellular morphology and elemental uptake that was mainly related to culture medium. Furthermore, schwertmannite with the typical morphology of aggregated spheres covered by some 鈥減incushions鈥?was precipitated first in bacterial cultures in the favorable pH range of 2.9 卤 0.1 to 2.6 卤 0.1. Some of schwertmannite could be transformed to lozenge-shaped jarosite, due to a successively decreasing of pH values. However, the jarosite transformation represented a lag period of 5 and 4 days in the chloride-rich cultures with sulfate at a low level, compared to the cultures with sulfate at a high level, which could be attributed to the influence of sulfate requirement and chloride acclimation.