Dominance of sulfur-fueled iron oxide reduction in low-sulfate freshwater sediments.

ABSTRACT: A central tenant in microbial biogeochemistry is that microbial metabolisms follow a predictable sequence of terminal electron acceptors based on the energetic yield for the reaction. It is thereby oftentimes assumed that microbial respiration of ferric iron outcompetes sulfate in all but high-sulfate systems, and thus sulfide has little influence on freshwater or terrestrial iron cycling. Observations of sulfate reduction in low-sulfate environments have been attributed to the presumed presence of highly crystalline iron oxides allowing sulfate reduction to be more energetically favored. Here we identified the iron-reducing processes under low-sulfate conditions within columns containing freshwater sediments amended with structurally diverse iron oxides and fermentation products that fuel

SUBMITTER: Hansel CM 

PROVIDER: S-EPMC4611504 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature