Cable bacteria generate a firewall against euxinia in seasonally hypoxic basins

• DOI: 10.1073/pnas.1510152112
• Publication Date: 2015-10-08T02:44:21Z
• Authors: Dorina Seitaj; Regina Schauer; Fatimah Sulu-Gambari; Silvia Hidalgo-Ma...; Sairah Y. Malkin; Laurine D. W. Bur...; Caroline P. Slomp; Filip J. R. Meysman
• Keywords: Firewall (physics)

Seasonal oxygen depletion (hypoxia) in coastal bottom waters can lead to the release and persistence of free sulfide (euxinia), which is highly detrimental marine life. Although hypoxia relatively common, reports euxinia are less frequent, suggests that certain environmental controls delay onset euxinia. However, these their prevalence poorly understood. Here we present field observations from a seasonally hypoxic basin (Grevelingen, The Netherlands), suggest activity cable bacteria, recently discovered group sulfur-oxidizing microorganisms inducing long-distance electron transport, waters. Our results reveal remarkable seasonal succession sulfur cycling pathways, was observed over multiple years. Cable bacteria dominate sediment geochemistry winter, whereas, after summer hypoxia, Beggiatoaceae mats colonize sediment. specific electrogenic metabolism generates large buffer sedimentary iron oxides before captures surface sediment, thus likely preventing development water As many systems, this euxinia-preventing firewall mechanism could be widely active, may explain why infrequently ocean.