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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) - PowerPoint PPT Presentation
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Initial Initial Geochemical Geochemical and and Microbiological Microbiological CharacterizationCharacterizationof Henderson Fluidsof 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?
BIOSCIENCE SAMPLING TEAMBIOSCIENCE SAMPLING TEAM
Templeton: Henderson DUSEL Capstone Workshop May 4-7th
Tom Kieft (New Mexico Tech)for
Alexis Templeton (University of Colorado – Boulder)
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 M)
Abundant nitrogen species:includes NO3
-, NO2- , N2O, NH4
+
Flowing boreholes variably mixed with oxygen
O 2 concentrations increase
as borehole flow-rate decreases
From D1 D3
O2 levels drop 1000x within 1 hour of packer-insertion
D1
D2
D3
Establishing the basic chemistry, nutrient levels and cell numbers Establishing the basic chemistry, nutrient levels and cell numbers in deeply-sourced, hot fluids:in deeply-sourced, hot fluids:
Natural Fracture Surface: Degassing CONatural Fracture Surface: Degassing CO22
Can also detect NCan also detect N22O (6-18 microM), only low CHO (6-18 microM), only low CH44 (sub-microM), and H (sub-microM), and H22 not measured yet. not measured yet.
CO2 Movie:
High CO2 important for autotrophic growth
Fe-oxidesFe-oxides
SulfatesSulfates
FeFe2+2+ rapidly oxidizes and oxide and sulfate minerals precipitate rapidly oxidizes and oxide and sulfate minerals precipitate
New minerals hard to structurally identify – relatively amorphous
What’s the disequilibrium between the fluids and the surface? Oxic-Anoxic Interface
Adjacent to the Fracture: Adjacent to the Fracture: Abundant Mn(IV)-oxides form black mineral coatings on the tunnel walls.Abundant Mn(IV)-oxides form black mineral coatings on the tunnel walls.
LBB-testShows Mn(IV)In minerals;
Mn(II) in fluids
First assessement: First assessement: Microbial Diversity in the Ancient FluidsMicrobial Diversity in the Ancient Fluids
10%
14%
29%
14%
3%
3%
17%
10%
Fungus; AscomycotaGreen Non-Sulfur or ChlorofexiDelta-ProteobacteriumBeta-ProteobacteriumAlpha-ProteobacteriumSpirocheteActinobacteriumFirmicutes; Clostridium
Data from John Spear, CSM
Surprising abundance ofEukaryotic fungal sequences..
Second assessment: Second assessment: Microbial Diversity in fluids of varying chemistryMicrobial Diversity in fluids of varying chemistry
(samples only separated by meters….)(samples only separated by meters….)
More dilute fluids
(7025-D1), pre-packer:
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)
Abundant Nitrospira
Remarkable diversity (~27 other groups)
•See John Spear talk on Friday…
Thermophilic Metal-oxidizing bacteria?Thermophilic Metal-oxidizing bacteria?
Microbes more abundant in the Fe-oxide matsMicrobes more abundant in the Fe-oxide mats
Rapid growth on Mn-media at 50°C using D4 mineral mat! Rapid growth on Mn-media at 50°C using D4 mineral mat! First 3 isolates being sequencedFirst 3 isolates being sequenced
Water and Mat samples:
Fe-oxidizing bacteria Mn-oxidizing bacteria
Establish enrichments:
*site-specific Henderson medium*
with and without organicsnear-neutral pHstabilized on mineral surfacesculture at 40°C-55°C
Growth onFe-media alsosuccessful…
DNA-labeled cells
Fe-oxide particles
Dissolved Oxygen now below detection
Now target anaerobic enrichments:Isolates for biochemical and proteomic studies
Anaerobic Fe-oxidizers
Mn-reducersFe-reducers
Sulfate-reducers
In-situ biofilms recently
extracted for analysis
Summary to-dateSummary to-date• Yes, microorganisms are present in the fluids, at low cell numbers.
• The fluid chemistry at Henderson is unique due to water-rock interaction, which has implications for the likely modes of metabolism and enzymatic activities.
– CO2 and sulfate concentrations are very high– N and C nutrient levels are above detection limits, but not P– Millimolar concentrations of Mn, Fe and Zn
• Fluid chemistry will vary significantly depending upon location inside vs. outside mineralized rock.
• The microbial diversity is high and includes unexpected fungal sequences
• There exists unexpected potential for a subsurface microbial N-cycleNH4
+, NO2-, NO3
- and N2O all abundant (naturally or not?)
• Microbial organisms are more abundant at the oxic-anoxic interface, where the Fe-oxide mineral mats are forming.
• Initial culturing efforts targeting Fe and Mn-oxidizing bacteria appear to be successful: sequenced isolates anticipated in the near-term, to be compared to clone libraries.
• Noble gas & stable-isotope geochemistry will constrain the age & source of the fluids.– Preliminary 14C data shows 26,000 years