Differential utilization and speciation transformation oforthorhombic α-S8 and amorphous μ-S bysubstrate-acclimated mesophilic Acidithiobacillus ferrooxidans
(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)
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