Active microbial sulfate reduction in fluids of serpentinizing peridotites of the continental subsurface

Serpentinization of peridotites in Earth’s mantle is associated with the generation of hydrogen and low molecular weight organics that could support subsurface life. Studies of microbial metabolisms in peridotite-hosted environments have focused primarily on methanogenesis, yet DNA sequences, isotop...

Full description

Saved in:
Bibliographic Details
Published in:Communications earth & environment 2021-05, Vol.2 (1), Article 84
Main Authors: Glombitza, Clemens, Putman, Lindsay I., Rempfert, Kaitlin R., Kubo, Michael D., Schrenk, Matthew O., Templeton, Alexis S., Hoehler, Tori M.
Format: Article
Language:English
Subjects:
Boreholes
Deoxyribonucleic acid
DNA
Earth mantle
Gene sequencing
Low molecular weights
Metabolism
Methanogenesis
Microorganisms
Organic acids
Peridotite
Radioactive tracers
Substrates
Sulfate reduction
Sulfates
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Serpentinization of peridotites in Earth’s mantle is associated with the generation of hydrogen and low molecular weight organics that could support subsurface life. Studies of microbial metabolisms in peridotite-hosted environments have focused primarily on methanogenesis, yet DNA sequences, isotopic composition of sulfides and thermodynamic calculations suggest there is potential for microbial sulfate reduction too. Here, we use a sulfate radiotracer-based method to quantify microbial sulfate reduction rates in serpentinization fluids recovered from boreholes in the Samail Ophiolite, Oman and the California Coast Range Ophiolite, USA. We find that low levels of sulfate reduction occur at pH up to 12.3. These low levels could not be stimulated by addition of hydrogen, methane or small organic acids, which indicates that this metabolism is limited by factors other than substrate availability. Cellular activity drops at pH > 10.5 which suggests that high fluid pH exerts a strong control on sulfate-reducing organisms in peridotites.
ISSN:2662-4435
2662-4435
DOI:10.1038/s43247-021-00157-z