Table 1

Fe(III)-reducing and magnetic iron oxide-forming activities at 60°C in materials obtained from deep terrestrial subsurface environments (21).

Source of microorganismsActivities with electron donor added into cultures*
Taylorsville Basin, sedimentary rocks+++
Piceance Basin, drilling fluids+++++
  • * The plus sign indicates that Fe(III) reduction and magnetic mineral formation were observed within 5 days of incubation.