Archaea

1. Possibly FeS2 BaSO3 crystals FeS2 framboid ZnS mineral coating Biofilm interior with various mineral morphologies Biofilm cross section showing dense exopolysaccharide matrix DNA from fissure water and rock biofilm samples collected from 3m, 6m and 9m into a borehole with fracture water ~ 3 Myr old, was amplified, fragmented and hybridized to our high density 16S microarrays containing 500,000 probes capable of detecting 9,381 prokaryotic OTUs. Clone libraries of 16S rDNA were also generated in order to validate array results. Scanning electron microscopy was used to visualize biofilm architecture, while XRD and EDX-S were used to confirm mineral identities. Planktonic community composition Biofilm community composition = detected in clone library and array = detected by array only = present in planktonic also = only present in biofilm Comparison of planktonic and biofilm microbial communities in fracture water from the deep subsurface of the Witwatersrand Basin, South Africa. Terry Hazen1, Eoin Brodie1, Fred Brockman2, Duane Moser2, Tom Gihring2, David Culley2, Li-Hung Lin3, Thomas Pray4, Gary Andersen1, Paul Richardson1,5, Lisa Pratt6 and Tullis Onstott4. 1Lawrence Berkeley National Lab, 2Pacific Northwest National Lab, 3National Taiwan University, 4Princeton University, 5Joint Genome Institute, 6Indiana University Results Background A deep-branching clade of nearly identical Desulfotomaculum-like, or DLO, 16S rDNA sequences (>99% homology) has been identified as the dominant microorganism in fracture water (14 Kyr to 20 Myr old) from multiple Au mines of the Witwatersrand Basin. The DLO is only the dominant form in the planktonic phase of the deepest (2 – 3 km depth), most saline fracture water and has not been reported as part of the community structure in biofilms that occupy deep, open boreholes with flowing fracture water. Here we compare fracture water planktonic communities from a recently drilled borehole in one mine with biofilm samples collected from an existing borehole at another mine in the Witwatersrand Basin. NH3+ oxidizer Methanotroph Metal-reducers S-oxidizer Acetogens Physical and chemical characteristics of planktonic and biofilm samples N-fixers S-oxidizer Archaea DLO-like Methods High intensity Low intensity High Density Microarray analysis of prokaryotes in planktonic and biofilm gold mine communities. Conclusions Biofilm microbial communities in open boreholes are considerably more diverse than planktonic communities present in fracture water and appear to contain many of the functional groups expected given the geochemistry of an ecosystem where highly reduced, metal, sulfide, H2 and CH4 rich water encounter oxygenated mine air. Acknowledgements Harmony Gold Mine, Inc. for providing access to the boreholes at Evander Mine. Evander geologists Colin Ralston and Pete Roberts. This research was supported by grant EAR-9978267 from the National Science Foundation LExEn program to T.C. Onstott. Contacts:tullis@princeton.edu – elbrodie@lbl.gov – tchazen@lbl.gov