Mercury capture into biogenic amorphous selenium nanospheres produced by mercury resistant Shewanella putrefaciens 200

► Shewanella putrefaciens 200 can produce reactive amorphous Se nanospheres. ► S. putrefaciens 200 reduced Hg(II) rapidly. ► Selenium nanoparticles efficiently sequester elemental Hg. ► Mercury and selenium was co-removed as stable HgSe nanoparticles. ► No secondary mercury pollution such as methylation or volatilization was formed. Shewanella putrefaciens 200, resistant to high concentration of Hg(II), was selected for co-removal of mercury and selenium from aqueous medium. Biogenic Hg(0) reduced from Hg(II) by S. putrefaciens 200 was captured into extracellular amorphous selenium nanospheres, resulting in the formation of stable HgSe nanoparticles. This bacterial reduction could be a new strategy for mercury removal from aquatic environments without secondary pollution of mercury methylation or Hg(0) volatilization.