Measuring Microbial Activity in Deep Subsurface Environments
Author Information
Author(s): Jayme Feyhl-Buska, Fabai Wu, Isaiah E. Smith, Douglas E. LaRowe, Alberto Robador, Brittany Kruger, Magdalena R. Osburn, Jan P. Amend
Primary Institution: University of Southern California
Hypothesis
Can calorimetric measurements reveal microbial activity in the deep continental subsurface?
Conclusion
The study found that amino acid amendments significantly stimulated microbial activity in deep subsurface fluids, indicating a potential for metabolic activation under specific conditions.
Supporting Evidence
- Heat flow measurements indicated very low metabolic rates in unamended groundwater samples.
- Formate addition resulted in a significant increase in heat flow and cell density.
- Amino acid amendments led to a pronounced metabolic response in the microbial community.
Takeaway
Scientists measured how active tiny living things are deep underground by checking how much heat they produce when given food. They found that adding certain foods made them much more active.
Methodology
The study used a nanocalorimeter to measure heat produced by microorganisms in groundwater samples from six boreholes at varying depths, with amendments of electron donors and acceptors.
Limitations
The study's findings are limited to the specific conditions and concentrations tested, which may not fully represent natural environments.
Digital Object Identifier (DOI)
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