04 Jul 2019
 | 04 Jul 2019
Status: this discussion paper is a preprint. It has been under review for the journal Biogeosciences (BG). The manuscript was not accepted for further review after discussion.

Cryptic role of tetrathionate in the sulfur cycle: A study from Arabian Sea oxygen minimum zone sediments

Subhrangshu Mandal, Sabyasachi Bhattacharya, Chayan Roy, Moidu Jameela Rameez, Jagannath Sarkar, Svetlana Fernandes, Tarunendu Mapder, Aditya Peketi, Aninda Mazumdar, and Wriddhiman Ghosh

Abstract. To explore the potential role of tetrathionate in the sulfur cycle of marine sediments, the population ecology of tetrathionate-forming, oxidizing, and respiring microorganisms was revealed at 15–30 cm resolution along two, ~ 3-m-long, cores collected from 530- and 580-mbsl water-depths of Arabian Sea, off India’s west coast, within the oxygen minimum zone (OMZ). Metagenome analysis along the two sediment-cores revealed widespread occurrence of the structural genes that govern these metabolisms; high diversity and relative-abundance was also detected for the bacteria known to render these processes. Slurry-incubation of the sediment-samples, pure-culture isolation, and metatranscriptome analysis, corroborated the in situ functionality of all the three metabolic-types. Geochemical analyses revealed thiosulfate (0–11.1 µM), pyrite (0.05–1.09 wt %), iron (9232–17234 ppm) and manganese (71–172 ppm) along the two sediment-cores. Pyrites (via abiotic reaction with MnO2) and thiosulfate (via oxidation by chemolithotrophic bacteria prevalent in situ) are apparently the main sources of tetrathionate in this ecosystem. Tetrathionate, in turn, can be either converted to sulfate (via oxidation by the chemolithotrophs present) or reduced back to thiosulfate (via respiration by native bacteria); 0–2.01 mM sulfide present in the sediment-cores may also reduce tetrathionate abiotically to thiosulfate and elemental sulfur. Notably tetrathionate was not detected in situ – high microbiological and geochemical reactivity of this polythionate is apparently instrumental in the cryptic nature of its potential role as a central sulfur cycle intermediate. Biogeochemical roles of this polythionate, albeit revealed here in the context of OMZ sediments, may well extend to the sulfur cycles of other geomicrobiologically-distinct marine sediment horizons.

Subhrangshu Mandal et al.

Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement

Subhrangshu Mandal et al.

Subhrangshu Mandal et al.


Total article views: 802 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
532 247 23 802 53 34 29
  • HTML: 532
  • PDF: 247
  • XML: 23
  • Total: 802
  • Supplement: 53
  • BibTeX: 34
  • EndNote: 29
Views and downloads (calculated since 04 Jul 2019)
Cumulative views and downloads (calculated since 04 Jul 2019)

Viewed (geographical distribution)

Total article views: 814 (including HTML, PDF, and XML) Thereof 814 with geography defined and 0 with unknown origin.
Country # Views %
  • 1


Latest update: 22 Sep 2023
Short summary
Sulfur cycling is a crucial component of sediment biogeochemistry within the marine realm. Microbial processes of sulfur cycle work in conjunction with the carbon cycle to remineralize organic matters sequestered in the sea-bed, influenceing metal deposition. Whereas thiosulfate has long been appreciated as a key junction in the sulfur cycle of global marine sediment, the present geomicrobial study brings to the fore hitherto-unappreciated roles of tetrathionate.