1 / 37

The Subsurface Biosphere

laverne
Download Presentation

The Subsurface Biosphere

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

    1. The Subsurface Biosphere Tom Kieft New Mexico Inst. of Mining and Technology T. C. Onstott Princeton University

    3. Major accomplishments & findings: Tracer technologies Extended known limits of biosphere to > 3 km depth Established biomass & biodiversity Isolates in Culture Collections Correlated microbial activity with geological interfaces Rates of subsurface microbial activity Long-term survival of subsurface microbes

    12. Sampling Rocks from freshly mined face Cores Fissure water from flowing boreholes biofilms

    25. Pyrococcus in mine fissure water? - a biological tracer of upwelling geothermal water? Fissure water characteristics: Anoxic 60 C Pyrococcus abysii Found at deep sea hydrothermal vents Anaerobic Growth at 67-102 C Optimum: 95 C

    26. Enrichments: Fe(III), Mn(IV), NO3-, So, SO42- reducers, So & Mn(II) oxidizers, methanogens, acetogens, methanotrophs, and fermenters. Samples inoculated aerobically/ anaerobically, +/-NaCl, +/- H2 & MPN’s. Incubate up to 6 months at RT or 60oC. Transfer, isolate & characterize growth vs. T, pH, salinity, radiation. 16Sr DNA & archive.

    28. Thermus multireducens – isolated from a West Rand Au mine Reduces a variety of electron acceptors: O2, nitrate, Fe(III), Mn(IV), S0, Co(III), Cr(VI), U(VI), Tc(VII) Thermophilic: optimum temp. = 650C Relatively radiation resistant D37 = 2000 Gy

    37. Results to date: Four new bacterial species and many new 16S rDNA sequences. Hyperthermophilic(?) Archaea may reflect deep circulating groundwater (>1 Ma). Radiolysis is source of H2 at West Rand

    38. Further questions: Are the hyperthermophiles really hyperthermophiles? Does autotrophy support subsurface biosphere? What is the source of NH3? What are the in situ microbial growth rates?

More Related