Formation of Nanoscale Elemental Silver Particles via Enzymatic Reduction by Geobacter sulfurreducens

Geobacter sulfurreducens reduced Ag(I) (as insoluble AgCl or Ag⁺ ions), via a mechanism involving c-type cytochromes, precipitating extracellular nanoscale Ag(0). These results extend the range of metals known to be reduced by Geobacter species and offer a method for recovering silver from contaminated water as potentially useful silver nanoparticles.