Comparative study of sulfur utilization and speciation transformation of two elemental sulfur species by thermoacidophilic Archaea Acidianus manzaensis YN-25

• Differential utilization of α-S8 and μ-S by A. manzaensis was evaluated.
• SEM, FT-IR, XRD and Raman spectroscopy and S K-edge XANES analyses were used for characterization.
• A. manzaensis grew faster in μ-S than in α-S8 during exponential growth phase.
• The surfaces of α-S and μ-S were modified differently by A. manzaensis.
• After grown on by A. manzaensis μ-S was mostly converted into α-S8.

The sulfur utilization and speciation transformation of two elemental sulfur species (orthorhombic α-S8 and amorphous μ-S) by thermoacidophilic Archaea strain Acidianus manzaensis YN-25 was comparatively studied. The results of cell growth and sulfur oxidation behavior showed that A. manzaensis cultured on μ-S grew faster (about 24 h earlier to reach stationary phase than that on α-S8) and produced more H+ and SO42−. Results of scanning electron microscopy indicated that the surfaces of μ-S and α-S8 were differently bio-corroded by A. manzaensis into loose porosities and pits, respectively. Fourier transform-infrared spectroscopy analysis indicated both μ-S and α-S8 were adsorbed by the cells. X-ray diffraction and Raman spectra analysis indicated that μ-S was mostly converted into α-S8 after A. manzaensis cell growth while α-S8 was not transformed into a different allotrope. The fitted result of sulfur K edge XANES spectra further showed that the μ-S after growth of A. manzaensis were composed of 92.1% α-S8 and 7.9% μ-S, while no change in composition for α-S8 was found.