Isolation and genomic analysis of “ Metallumcola ferriviriculae” MK1, a Gram-positive, Fe(III)-reducing bacterium from the Soudan Underground Mine, an iron-rich Martian analog site

• Published in: Applied and environmental microbiology Vol. 90; no. 8; p. e0004424
• Main Authors: Hsu, David, Flynn, Jack R., Schuler, Christopher J., Santelli, Cara M., Toner, Brandy M., Bond, Daniel R., Gralnick, Jeffrey A.
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 21.08.2024
• Subjects: Acetic acid; Anaerobic conditions; Anaerobic microorganisms; Bacteria; Boreholes; Brines; Cell surface; Cytochrome; Cytochromes; Cytoplasmic membranes; Electron transfer; Ferric Compounds - metabolism; Genome, Bacterial; Genomic analysis; Geomicrobiology; Gram-negative bacteria; Gram-positive bacteria; Gram-Positive Bacteria - classification; Gram-Positive Bacteria - genetics; Gram-Positive Bacteria - isolation & purification; Gram-Positive Bacteria - metabolism; Iron; Iron - metabolism; Membranes; Metagenomics; Microorganisms; Mining; Minnesota; Oxidation-Reduction; Peptidoglycans; Phylogeny; RNA, Ribosomal, 16S - genetics; rRNA 16S; Special Series: Planetary Microbiology; Underground mines; Minnesota; deep biosphere; subsurface microbiology; iron reduction
• ISSN: 0099-2240; 1098-5336; 1098-5336
• DOI: 10.1128/aem.00044-24

The Soudan Underground Mine State Park gives access to understudied regions of the deep terrestrial subsurface that potentially predate the Great Oxidation Event. Studying organisms that have been relatively unperturbed by surface conditions for as long as 2.7 billion years may give us a window into ancient life before oxygen dominated the planet. Additionally, studying microbes from anoxic and iron-rich environments can help us better understand the requirements of life in analogous environments, such as on Mars. The isolation and characterization of “ Metallumcola ferriviriculae” strain MK1 give us insights into a novel genus and species that is distinct both from its closest related isolates and from iron reducers characterized to date. “ M. ferriviriculae” strain MK1 may also act as a model organism to study how the processes of sporulation and germination are affected by insoluble extracellular acceptors, as well as the impact of spores in the deep terrestrial biosphere.