Between Dec 19, 2024 and Jan 2, 2025, datasets can be submitted to DRUM but will not be processed until after the break. Staff will not be available to answer email during this period, and will not be able to provide DOIs until after Jan 2. If you are in need of a DOI during this period, consider Dryad or OpenICPSR. Submission responses to the UDC may also be delayed during this time.

Browsing by Author "University of Minnesota Bailey Geobiology Lab"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Giant sulfur bacteria host intracellular endobionts
    (2019-12-06) Flood, Beverly E; Leprich, Dalton J; Delherbe, Nathalie; Hunter, Ryan; Bailey, Jake V; beflood@umn.edu; Flood, Beverly E; University of Minnesota Bailey Geobiology Lab
    Eukaryotic organelles, such as mitochondria and chloroplasts, are thought to be 12 derived from symbiotic bacteria that were hosted by a proto-eukaryotic microbe in the 13 deep evolutionary past. Despite their potential relevance to eukaryote evolution, 14 endosymbiotic relationships involving free-living, viable bacterial or archaeal host cells, 15 have not been previously established in the modern biosphere. Here we show that some 16 populations of the largest known bacteria, Candidatus Thiomargarita spp., host bacterial 17 populations within their cells, providing a singular example of a free-living marine 18 bacterium that hosts endobiont bacteria. Multiple lines of evidence show that the host and 19 endobiont cells are metabolically active. The phylogeny of these endobiont bacteria places 20 them within a clade that includes known animal endosymbionts – specifically 21 gammaproteobacteria that live within siboglinid tubeworms. Metagenomic results indicate 22 that the metabolism of the endobionts is remarkably similar to that of the host Ca. 23 Thiomargarita cells, which are known for their remarkable ability to store metabolites 24 such as nitrate, suggesting a potentially parasitic, rather than mutualistic, relationship. In 25 addition to establishing the viability of a host bacterium with endobiont bacteria, these 26 findings extend the range of hosts for sulfide-oxidizing endosymbionts across two domains 27 of life, from animals to giant bacteria.
  • Thumbnail Image
    Item
    Sulfur bacteria promote dissolution of authigenic carbonates at marine methane seeps
    (2021-01-27) Leprich, Dalton J.; Flood, Beverly E.; Schroedl, Peter R.; Ricci, Elizabeth; Marlow, Jeffery J.; Girguis, Peter R.; Bailey, Jake V.; beflood@umn.edu; Flood, Beverly E.; University of Minnesota Bailey Geobiology Lab
    Carbonate rocks at marine methane seeps are commonly colonized by sulfur-oxidizing bacteria that co-occur with etch pits that suggest active dissolution. We show that sulfur-oxidizing bacteria are abundant on the surface of an exemplar seep carbonate collected from Del Mar East Methane Seep Field, USA. We then used bioreactors containing aragonite mineral coupons that simulate certain seep conditions to investigate plausible in situ rates of carbonate dissolution associated with sulfur-oxidizing bacteria. Bioreactors inoculated with a sulfur-oxidizing bacterial strain, Celeribacter baekdonensis LH4, growing on aragonite coupons induced dissolution rates in sulfidic, heterotrophic, and abiotic conditions of 1773.97 (±324.35), 152.81 (±123.27), and 272.99 (±249.96) Mol CaCO3  cm-2  yr-1, respectively. Steep gradients in pH were also measured within carbonate-attached biofilms using pH-sensitive fluorophores. Together, these results show that the production of acidic microenvironments in biofilms of sulfur-oxidizing bacteria are capable of dissolving carbonate rocks, even under well-buffered marine conditions. Our results support the hypothesis that authigenic carbonate rock dissolution driven by lithotrophic sulfur-oxidation constitutes a previously unknown carbon flux from the rock reservoir to the ocean and atmosphere.