Initial Geochemical and Microbiological Characterization of Henderson Fluids. How does knowledge of the site-specific chemistry at Henderson enhance our ability to identify subsurface microbial organisms (phylogentically and functionally)
-- and their direct dependency upon fluid-rock interaction?
Tom Kieft (New Mexico Tech)
Alexis Templeton (University of Colorado – Boulder)
BIOSCIENCE SAMPLING TEAM
Templeton: Henderson DUSEL Capstone Workshop May 4-7th
in deeply-sourced, hot fluids:
Flowing boreholes variably mixed with oxygen
Fluid Chemistry: 7025 level
Warm, ~40C; pH 5.9 to 6.2
Dissolved O2: 0.3 to 3.8 mg/L
High DIC (~30 mM)
High Mn2+, Fe2+ (1 to 20 mM)
High SO42- (4 to 48 mM)
Trace metals: Zn > Ni > Mo
Low (but detectable) organics (50 mM)
Abundant nitrogen species:
includes NO3-, NO2- ,N2O, NH4+
O2 concentrations increase
as borehole flow-rate decreases
From D1 D3
O2 levels drop 1000x within 1 hour of packer-insertion
CO numbers 2 Movie:
High CO2 important for autotrophic growth
Natural Fracture Surface: Degassing CO2
Can also detect N2O (6-18 microM), only low CH4 (sub-microM), and H2 not measured yet.
Fe2+ rapidly oxidizes and oxide and sulfate minerals precipitate
New minerals hard to structurally identify – relatively amorphous
Adjacent to the Fracture: surface?
Abundant Mn(IV)-oxides form black mineral coatings on the tunnel walls.
Mn(II) in fluids
Surprising abundance of
Eukaryotic fungal sequences..
Data from John Spear, CSM
More dilute fluids surface?
Dominated by uncultured beta-Proteobacteria (e.g. Japanese Gold Mine): 80%
Fluids with high Fe, Mn, sulfate, NH4+, N2O (7025-D4) post-packer:
Abundant delta-Proteobacteria (SRB)
Remarkable diversity (~27 other groups)Second assessment: Microbial Diversity in fluids of varying chemistry(samples only separated by meters….)
DNA-labeled cells surface?
Thermophilic Metal-oxidizing bacteria?
Water and Mat samples:
*site-specific Henderson medium*
with and without organics
stabilized on mineral surfaces
culture at 40°C-55°C
Microbes more abundant in the Fe-oxide mats
Rapid growth on Mn-media at 50°C using D4 mineral mat! First 3 isolates being sequenced
Dissolved Oxygen now below detection surface?
Now target anaerobic enrichments:
Isolates for biochemical and proteomic studies
In-situ biofilms recently
extracted for analysis
NH4+, NO2-, NO3- and N2O all abundant (naturally or not?)