Send to

Choose Destination
FEMS Microbiol Ecol. 2004 Jul 1;49(1):137-43. doi: 10.1016/j.femsec.2003.08.018.

Iron respiration by Acidiphilium cryptum at pH 5.

Author information

Department of Civil, Environmental and Architectural Engineering, University of Colorado, Engineering Center ECOT 441, 1111 Engineering Drive, CB 428, Boulder, CO 80309, USA.


The growth of acidophilic iron respiring bacteria at pH > 4.5 may be a key to the transition from acidic to circumneutral conditions that would occur during restoration of acid mine drainage sites. Flasks containing Acidiphilium cryptum ATCC 33463 were incubated initially under aerobic conditions in liquid medium containing Fe(2)(SO(4))(3) and glucose at an initial pH of 5. Significant iron respiration was observed after flasks were sealed to prevent oxygenation; at the same time, medium pH increased from 4.5 to 6. No soluble Fe(III) was detected throughout the experiments, consistent with pH conditions, indicating that bacteria were able to respire using precipitated ferric iron species. In addition, the concentration of soluble Fe(2+) reached a plateau, even though iron respiration appeared to continue, possibly due to precipitation of mixed Fe (II)/Fe(III)-oxide as magnetite. Results suggest that A. cryptum has a wide range of pH tolerance, which may enable it to play a role in controlling acid generation by means of establishing growth conditions favorable to neutrophilic bacteria such as sulfate reduction.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for Wiley
Loading ...
Support Center