Open AccessEvaluation of electron‐shuttling compounds in microbial ferric iron reduction
Author(s) -
Straub Kristina L,
Schink Bernhard
Publication year - 2003
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(03)00130-7
Subject(s) - ferrihydrite , ferric , chemistry , geobacter sulfurreducens , ferrous , inorganic chemistry , electron transfer , iron bacteria , electron donor , nuclear chemistry , bacteria , photochemistry , biochemistry , organic chemistry , biofilm , biology , catalysis , adsorption , genetics
Iron‐reducing bacteria can transfer electrons to ferric iron oxides which are barely soluble at neutral pH, and electron‐shuttling compounds or chelators are discussed to be involved in this process. Experiments using semipermeable membranes for separation of ferric iron‐reducing bacteria from ferric iron oxides do not provide conclusive results in this respect. Here, we used ferrihydrite embedded in 1% agar to check for electron‐shuttling compounds in pure and in enrichment cultures. Geobacter sulfurreducens reduced spatially distant ferrihydrite only in the presence of anthraquinone‐2,6‐disulfonate, a small molecule known to shuttle electrons between the bacterial cell and ferrihydrite. However, indications for the production and excretion of electron‐shuttling compounds or chelators were found in ferrihydrite‐containing agar dilution cultures that were inoculated with ferric iron‐reducing enrichment cultures.