Iron reduction and mineralization of deep-sea iron reducing bacterium Shewanella piezotolerans WP3 at elevated hydrostatic pressures

Authors

  • W. F. Wu,

    1. Biogeomagnetism Group, Paleomagnetism and Geochronology Lab, Key Laboratory of the Earth's Deep Interior, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
    2. France-China Bio-Mineralization and Nano-Structures Laboratory, Chinese Academy of Sciences, Beijing, China
    Search for more papers by this author
  • F. P. Wang,

    1. State Key Laboratory of Ocean Engineering, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
    Search for more papers by this author
  • J. H. Li,

    1. Biogeomagnetism Group, Paleomagnetism and Geochronology Lab, Key Laboratory of the Earth's Deep Interior, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
    2. France-China Bio-Mineralization and Nano-Structures Laboratory, Chinese Academy of Sciences, Beijing, China
    Search for more papers by this author
  • X. W. Yang,

    1. State Key Laboratory of Ocean Engineering, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
    Search for more papers by this author
  • X. Xiao,

    1. State Key Laboratory of Ocean Engineering, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
    Search for more papers by this author
  • Y. X. Pan

    Corresponding author
    1. France-China Bio-Mineralization and Nano-Structures Laboratory, Chinese Academy of Sciences, Beijing, China
    • Biogeomagnetism Group, Paleomagnetism and Geochronology Lab, Key Laboratory of the Earth's Deep Interior, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
    Search for more papers by this author

Corresponding author: Y. X. Pan. Tel.: +86 10 8299 8406; fax: +86 10 6201 0846; e-mail: yxpan@mail.iggcas.ac.cn

Abstract

In this study, iron reduction and concomitant biomineralization of a deep-sea iron reducing bacterium (IRB), Shewanella piezotolerans WP3, were systematically examined at different hydrostatic pressures (0.1, 5, 20, and 50 MPa). Our results indicate that bacterial iron reduction and induced biomineralization are influenced by hydrostatic pressure. Specifically, the iron reduction rate and extent consistently decreases with the increase in hydrostatic pressure. By extrapolation, the iron reduction rate should drop to zero by ~68 MPa, which suggests a possible shut-off of enzymatic iron reduction of WP3 at this pressure. Nano-sized superparamagnetic magnetite minerals are formed under all the experimental pressures; nevertheless, even as magnetite production decreases, the crystallinity and grain size of magnetite minerals increase at higher pressure. These results imply that IRB may play an important role in iron reduction, biomineralization, and biogeochemical cycling in deep-sea environments.

Ancillary