Sulfide Oxidation Dynamics in Microbial Ecosystems

Sulphide oxidation underpins the global sulphur cycle by transforming reduced inorganic sulphur compounds into sulphate, a process central to marine and freshwater redox interfaces. Sulphur-oxidising microbes—including large filamentous bacteria and microscopic chemolithoautotrophs—colonise zones where oxygen and sulphide gradients intersect, such as sediment–water interfaces, hydrothermal vents and stratified water columns. These organisms employ specialised enzyme systems to harness chemical energy from sulphide, coupling it to carbon dioxide fixation and driving primary production in aphotic environments. Recent advances in single-cell genomics and community sequencing have revealed metabolic plasticity, genomic diversity and intricate microbial consortia that mediate sulphide fluxes. By linking molecular pathways to biogeochemical gradients, current research illuminates how shifts in redox conditions influence ecosystem function, nutrient cycling and the resilience of sulfidic habitats to environmental change.

Research from Nature Portfolio

High-resolution single-cell analyses of a model freshwater sulphur bacterium have uncovered unprecedented intracellular genetic heterogeneity, with multiple genome copies exhibiting divergent arrangements of transposable elements and 16S ribosomal RNA gene variants. This polyploid architecture appears to facilitate spatially resolved gene expression across intracellular compartments, suggesting a mechanism by which individual cells can adapt their sulphide oxidation pathways to fluctuating redox conditions. The discovery of widespread gene conversion hotspots and mobile element-mediated rearrangements points to an underappreciated source of metabolic innovation within key sulphur-oxidising taxa.

Research from all publishers

Investigations of giant sulphur-oxidising bacterial mats off the Namibian shelf have demonstrated that vacuolated filamentous cells host distinct epibiotic microbiomes. Metagenomic and amplicon data reveal host-specific enrichments of sulphide-oxidising Campylobacterota and syntrophic partners that recycle hydrogen and acetate, underpinning community resilience in high sulphide flux zones. In parallel, surveys of sediments beneath the Eastern Boundary Current System off Peru and Chile document spatial gradients in Desulfobacterota populations, with microdiverse assemblages of sulfate reducers and hydrogen-scavengers strongly correlated with local oxygen minima. These findings emphasise the interplay between sulphide oxidation, sulphate reduction and community structure across large-scale biogeographical gradients.

Sulfide Oxidation Dynamics in Microbial Ecosystems publication trend

The graph below shows the total number of articles in sulfide oxidation dynamics in microbial ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Sulphide oxidation: The enzymatic conversion of hydrogen sulphide or other reduced sulphur species into sulphate or intermediate sulphur compounds.

Chemolithoautotroph: An organism that obtains energy by oxidising inorganic molecules and fixes carbon dioxide as its carbon source.

Redox interface: A physical boundary in sediments or water columns where oxidising and reducing conditions overlap, generating steep chemical gradients.

rDsr pathway: The reverse dissimilatory sulfite reductase system used by sulphur-oxidising microbes to oxidise stored or environmental sulphide.

References

1. Community-like genome in single cells of the sulfur bacterium Achromatium oxaliferum. Nature Communications (2017).
2. Giant sulfur bacteria (Beggiatoaceae) from sediments underlying the Benguela upwelling system host diverse microbiomes. PLOS ONE (2021).
3. Bacterial community of sediments under the Eastern Boundary Current System shows high microdiversity and a latitudinal spatial pattern. Frontiers in Microbiology (2022).