Production of carbon-containing pyrite spherules induced by hyperthermophilic Thermococcales: a biosignature?

Frontiers in Microbiology

Microbiology

Aurore Gorlas¹  Camille Baya²  Sylvain Bernard²  Pierre Le Pape²  Chloé Truong²  Pauline Merrot²  Guillaume Morin²  François Guyot³ 

[1] CEA, CNRS, Institute for Integrative Biology of the Cell, Université Paris-Saclay, Gif-sur-Yvette, France;Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), MNHN, CNRS, IRD, Sorbonne Université, Paris, France;Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), MNHN, CNRS, IRD, Sorbonne Université, Paris, France;Institut Universitaire de France (IUF), Paris, France;

关键词: archaea;    biosignatures;    hydrothermal vents;    pyrite;    greigite;   

DOI  :  10.3389/fmicb.2023.1145781

 received in 2023-01-16, accepted in 2023-05-02,  发布年份 2023

来源: Frontiers

【 摘 要 】

Thermococcales, a major order of hyperthermophilic archaea inhabiting iron- and sulfur-rich anaerobic parts of hydrothermal deep-sea vents, are known to induce the formation of iron phosphates, greigite (Fe3S4) and abundant quantities of pyrite (FeS2), including pyrite spherules. In the present study, we report the characterization of the sulfide and phosphate minerals produced in the presence of Thermococcales using X-ray diffraction, synchrotron-based X ray absorption spectroscopy and scanning and transmission electron microscopies. Mixed valence Fe(II)-Fe(III) phosphates are interpreted as resulting from the activity of Thermococcales controlling phosphorus–iron–sulfur dynamics. The pyrite spherules (absent in abiotic control) consist of an assemblage of ultra-small nanocrystals of a few ten nanometers in size, showing coherently diffracting domain sizes of few nanometers. The production of these spherules occurs via a sulfur redox swing from S0 to S–2 and then to S–1, involving a comproportionation of (-II) and (0) oxidation states of sulfur, as supported by S-XANES data. Importantly, these pyrite spherules sequester biogenic organic compounds in small but detectable quantities, possibly making them good biosignatures to be searched for in extreme environments.

【 授权许可】

Unknown   
Copyright © 2023 Truong, Bernard, Le Pape, Morin, Baya, Merrot, Gorlas and Guyot.