|Title||Low temperature S0 biomineralization at a supraglacial spring system in the Canadian High Arctic|
|Author||Gleeson, D F; Williamson, C; Grasby, S E; Pappalardo, R T; Spear, J R; Templeton, A S|
|Source||Geobiology vol. 9, no. 4, 2011 p. 360-375, https://doi.org/10.1111/j.1472-4669.2011.00283.x|
|Alt Series||Earth Sciences Sector, Contribution Series 20110179|
|Media||paper; on-line; digital|
|Area||Borup Fiord; Ellesmere Island|
|Lat/Long WENS||-81.6667 -81.5000 81.0333 81.0000|
|Subjects||hydrogeology; geochemistry; environmental geology; sulphur; sulphur water; sulphur content; springs; spring water geochemistry|
|Illustrations||location maps; photographs; tables; pie charts; photomicrographs|
|Program||GEM: Geo-mapping for Energy and
Minerals, Sverdrup Sedimentary Basin|
|Released||2011 05 19|
|Abstract||Elemental sulfur (S0) is deposited each summer onto surface ice at Borup Fiord pass on Ellesmere Island, Canada, when high concentrations of aqueous H2S are discharged from a supraglacial spring system.
16S rRNA gene clone libraries generated fromsulfur deposits were dominated by b-Proteobacteria, particularly Ralstonia sp. Sulfur-cycling micro-organisms such as Thiomicrospira sp., and e-Proteobacteria such as Sulfuricurvales and Sulfurovumales spp.
were also abundant. Concurrent cultivation experiments isolated psychrophilic, sulfide-oxidizing consortia, which produce S0 in opposing gradients of Na2S and oxygen. 16S rRNA gene analyses of sulfur precipitated in gradient tubes show stable
sulfur-biomineralizing consortia dominated by Marinobacter sp. in association with Shewanella, Loktanella, Rubrobacter, Flavobacterium, and Sphingomonas spp. Organisms closely related to cultivars appear in environmental 16S rRNA clone libraries;
none currently known to oxidize sulfide. Once consortia were simplified to Marinobacter and Flavobacteria spp. through dilution-to-extinction and agar removal, sulfur biomineralization continued. Shewanella, Loktanella, Sphingomonas, and Devosia spp.
were also isolated on heterotrophic media, but none produced S0 alone when reintroduced to Na2S gradient tubes. Tubes inoculated with a Marinobacter and Shewanella spp. co-culture did show sulfur biomineralization, suggesting that Marinobacter may be
the key sulfide oxidizer in laboratory experiments. Light, florescence and scanning electron microscopy of mineral aggregates produced in Marinobacter experiments revealed abundant cells,with filaments and sheaths variably mineralized with
extracellular submicron sulfur grains; similar biomineralization was not observed in abiotic controls. Detailed characterization of mineral products associated with low temperature microbial sulfur-cycling may provide biosignatures relevant to future
exploration of Europa and Mars.|