中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 25 No. 9 September 2015 |
(1. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Biometallurgy of Ministry of Education,
Central South University, Changsha 410083, China;
3. Beijing Synchrotron Radiation Facility, Institute of High Energy Physics,
Chinese Academy of Sciences, Beijing 100049, China)
Abstract:The utilization and speciation transformation of α-S8 and μ-S by the typical mesophilic acidophilic strain Acidithiobacillus ferrooxidans ATCC 23270 were investigated. A. ferrooxidans cells first acclimated to the energy source α-S8 or μ-S, respectively. The results of cell growth and sulfur oxidation behavior showed that the strain grown on α-S8 entered slowly (about 1 d later) into the exponential phase, while grew faster in the exponential phase and attained higher maximal cell density and lower pH value than that on μ-S. After bio-corrosion, both of the two sulfur samples were evidently eroded and modified by A. ferrooxidans cells. After growth of A. ferrooxidans, the surface composition of amorphous μ-S became 63.1% μ-S and 36.9% α-S8, and that of orthorhombic α-S8 became 68.3% α-S8 and 31.7% μ-S, while the surface compositions of α-S8 and μ-S in sterile experiment were not changed, indicating that these two elemental sulfur species can be interconverted by A. ferrooxidans.
Key words: sulfur utilization; sulfur speciation transformation; α-S8; μ-S; Acidithiobacillus ferrooxidans