Radiolytically reworked Archean organic matter in a habitable deep ancient high-temperature brine.

ABSTRACT: Investigations of abiotic and biotic contributions to dissolved organic carbon (DOC) are required to constrain microbial habitability in continental subsurface fluids. Here we investigate a large (101-283 mg C/L) DOC pool in an ancient (>1Ga), high temperature (45-55 °C), low biomass (10²-10⁴ cells/mL), and deep (3.2 km) brine from an uranium-enriched South African gold mine. Excitation-emission matrices (EEMs), negative electrospray ionization (-ESI) 21 tesla Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS), and amino acid analyses suggest the brine DOC is primarily radiolytically oxidized kerogen-rich shales or reefs, methane and ethane, with trace amounts of C₃-C₆ hydrocarbons and organic sulfides. δ²H and δ

SUBMITTER: Nisson DM 

PROVIDER: S-EPMC10547683 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature