Large sulfur isotope fractionation by bacterial sulfide oxidation.

A sulfide-oxidizing microorganism, (DA), generates a consistent enrichment of sulfur-34 ( ) in the produced sulfate of +12.5 per mil or greater. This observation challenges the general consensus that the microbial oxidation of sulfide does not result in large enrichments and suggests that sedimentary sulfides and sulfates may be influenced by metabolic activity associated with sulfide oxidation.

Motility of Electric Cable Bacteria.

Unlabelled: Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces with a highly variable speed of 0.5 ± 0.