Tectonically-driven oxidant production in the hot biosphere

Abstract

Genomic reconstructions of the common ancestor to all life have identified genes involved in H2O2 and O2 cycling. Commonly dismissed as an artefact of lateral gene transfer after oxygenic photosynthesis evolved, an alternative is a geological source of H2O2 and O2 on the early Earth. Here, we show that under oxygen-free conditions high concentrations of H2O2 can be released from defects on crushed silicate rocks when water is added and heated to temperatures close to boiling point, but little is released at temperatures <80 °C. This temperature window overlaps the growth ranges of evolutionary ancient heat-loving and oxygen-respiring Bacteria and Archaea near the root of the Universal Tree of Life. We propose that the thermal activation of mineral surface defects during geological fault movements and associated stresses in the Earth’s crust was a source of oxidants that helped drive the (bio)geochemistry of hot fractures where life first evolved.

A mineral-based origin of Earth’s initial hydrogen peroxide and molecular oxygen

“…4 ) ( Fig. 1 C ) ( 26 , 51 , 56 , 57 ). In this case, the oxygen atoms in •OH and H 2 O 2 ultimately originate from water ( Fig.…”

“…Stress-induced ROS generation at silicate–water interfaces in several geological processes has been investigated ( 25 , 26 , 51 ). Experiments mimicking abrasion of quartz in turbulent subaqueous environments indicate that a significant amount of H 2 O 2 could be produced, creating and sustaining oxic microenvironments in Archean deltas and seashores ( 25 ).…”

“…Experiments mimicking abrasion of quartz in turbulent subaqueous environments indicate that a significant amount of H 2 O 2 could be produced, creating and sustaining oxic microenvironments in Archean deltas and seashores ( 25 ). Following the SBR-induced ROS formation, it is proposed that rock faulting in geothermal subsurface environments can lead to H 2 O 2 formation ( 51 ). However, a deep mechanistic ROS formation reaction framework of silicate–water interaction remains lacking, hindering further exploration of how general geological processes triggered the release of ROS to the early Earth at a global scale and drove the evolution of ROS-detoxifying system and oxygenic photosynthesis.…”

Abrasion of sedimentary rocks as a source of hydrogen peroxide and nutrients to subglacial ecosystems

“…Our results also indicate rock comminution can act as a source of NH4 + to the subglacial system. Crushing of glacial rock samples in the ball mill generates heat (Stone et al, 2022), which might have contributed to the NH4 + measured. However, there was no correlation between NH4 + and %N or %OC in the samples.…”

“…These have primarily focused on the potential reactivity of silicates after comminution (Gill-Olivas et al, 2021;Telling et al, 2015) and the release or production of gases during comminution (Gill-Olivas et al, 2021;Macdonald et al, 2018). It has been shown that comminution of certain rocks and minerals can generate strong redox agents, such as H2 (Saruwatari et al, 2004;Takehiro et al, 2011;Telling et al, 2015;Wakita et al, 1980;Edgar et al, 2022) and H2O2 (Bak et al, 2017;Borda et al, 2003;He et al, 2021;Edgar et al, 2022;Stone et al, 2022). These are expected to have an https://doi.org/10.5194/egusphere-2022-908 Preprint.…”