title: Rock geochemistry induces stress and starvation responses in the bacterial proteome.
abstract: Interactions between microorganisms and rocks play an important role in Earth system processes. However, little is known about the molecular capabilities microorganisms require to live in rocky environments. Using a quantitative label-free proteomics approach, we show that a model bacterium (Cupriavidus metallidurans CH34) can use volcanic rock to satisfy some elemental requirements, resulting in increased rates of cell division in both magnesium- and iron-limited media. However, the rocks also introduced multiple new stresses via chemical changes associated with pH, elemental leaching and surface adsorption of nutrients that were reflected in the proteome. For example, the loss of bioavailable phosphorus was observed and resulted in the upregulation of diverse phosphate limitation proteins, which facilitate increase phosphate uptake and scavenging within the cell. Our results revealed that despite the provision of essential elements, rock chemistry drives complex metabolic reorganization within rock-dwelling organisms, requiring tight regulation of cellular processes at the protein level. This study advances our ability to identify key microbial responses that enable life to persist in rock environments.
authors.affiliation: UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK.
authors.forename: Casey C
authors.initials: CC
authors.lastname: Bryce
authors.affiliation: Centre for Synthetic and Systems Biology, Institute of Structural and Molecular Biology, University of Edinburgh, Edinburgh, UK.
authors.forename: Thierry
authors.initials: T
authors.lastname: Le Bihan
authors.affiliation: Centre for Synthetic and Systems Biology, Institute of Structural and Molecular Biology, University of Edinburgh, Edinburgh, UK.
authors.forename: Sarah F
authors.initials: SF
authors.lastname: Martin
authors.affiliation: UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK.|Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Austria.
authors.forename: Jesse P
authors.initials: JP
authors.lastname: Harrison
authors.affiliation: Institute for Condensed Matter and Complex Systems, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK.|Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, The Netherlands.
authors.forename: Timothy
authors.initials: T
authors.lastname: Bush
authors.affiliation: Centre for Ecology and Hydrology, Bush Estate, Penicuik, Edinburgh, UK.
authors.forename: Bryan
authors.initials: B
authors.lastname: Spears
authors.affiliation: Centre for Ecology and Hydrology, Bush Estate, Penicuik, Edinburgh, UK.
authors.forename: Alanna
authors.initials: A
authors.lastname: Moore
authors.affiliation: Microbiology Unit, Belgian Nuclear Research Centre, SCK●CEN, Mol, Belgium.
authors.forename: Natalie
authors.initials: N
authors.lastname: Leys
authors.affiliation: Microbiology Unit, Belgian Nuclear Research Centre, SCK●CEN, Mol, Belgium.|Laboratory of Microbial Ecology and Technology, University of Ghent, Ghent, Belgium.
authors.forename: Bo
authors.initials: B
authors.lastname: Byloos
authors.affiliation: UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Cockell
mesh_terms: D049921:Cupriavidus / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D020543:Proteome / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D018707:Volcanic Eruptions
chemical_list: D020543:Proteome; D012987:Soil; D010758:Phosphorus; D007501:Iron