Microbial Synthesis and Characterization of Superparamagnetic Zn-Substituted Magnetite Nanoparticles.

The objective of this study is to examine microbial synthesis of magnetite and Zn-substituted magnetite nanoparticles by iron-reducing bacteria (Clostridium sp.) enriched from intertidal flat sediments. The magnetite nanoparticles were synthesized by the bacteria under anaerobic conditions at room temperature using akaganeite (β-FeOOH) or Zn-substituted akaganeite (β-ZnxFe1-xOOH) as a magnetite precursor during glucose fermentation. This research indicates that fermentation processes can establish the microbial synthesis of magnetite and Zn-substituted magnetite when conditions are at room temperature, ambient pressure, and pH values near neutral to slightly basic (pH < 8).