Expanded Diversity of Microbial Groups Capable of Anaerobic Pyrite Reduction and Assimilation of Dissolution Products

Journal Article · Sun Jun 22 00:00:00 EDT 2025 · Environmental Microbiology

DOI:https://doi.org/10.1111/1462-2920.70125· OSTI ID:2571055

Boyd, Eric S. ^[1]; Payne, Devon ^[1]

---

1. Montana State University, Bozeman, MT (United States)

Pyrite, the most abundant iron sulfide mineral in the Earth's crust, has traditionally been considered as a sink for iron and sulfur in the absence of oxygen. Recent research, however, has shown that anaerobic methanogenic archaea can reductively dissolve pyrite and assimilate its products as sources of iron and sulfur. This study explores whether other anaerobic bacteria, including fermentative, nitrate-, iron oxide-, fumarate-, and sulfate-respiring bacteria, can also reduce pyrite and use its dissolution products as sources of iron and sulfur. Results indicate that heterotrophic bacteria respiring fumarate or sulfate, or fermenting organic carbon, can reduce pyrite and assimilate released iron and sulfur. In contrast, nitrate- or iron oxide-respiring cells did not reduce pyrite, suggesting that microbial pyrite reduction is metabolism-specific. All strains capable of reducing pyrite could also use mackinawite as an iron and sulfur source. With the exception of fermentative Bacteroides, strains did not require direct contact with pyrite to reduce the mineral, indicating extracellular electron transfer via electron shuttles. These findings expand the known diversity of microbial groups capable of pyrite reduction and highlight the mineral's lability in various anaerobic environments, with potential implications for the biogeochemical cycles of iron, sulfur, carbon, and oxygen.

• Research Organization: Montana State University, Bozeman, MT (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB)
• Grant/Contract Number: SC0020246
• OSTI ID: 2571055
• Alternate ID(s): OSTI ID: 3001326
• Report Number(s): DOE--0020246
• Journal Information: Environmental Microbiology, Journal Name: Environmental Microbiology Journal Issue: 6 Vol. 27; ISSN 1462-2920; ISSN 1462-2912
• Publisher: Wiley
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
59 BASIC BIOLOGICAL SCIENCES
extracellular electron transfer
extracellular electron transfer
fermentation
fumarate
iron
mackinawite (FeSmack)
respiration
sulfate
sulfur
fermentation
fumarate
iron
mackinawite (FeSmack)
respiration
sulfate
sulfur