Coevolution of Life and Planet: role of trace metal availability in the evolution of biogeochemically relevant redox metalloenzymes

ongoing

Earth’s geosphere and biosphere have coevolved over time, influencing each other’s stability and keeping our planet habitable over the last 4 billion years. Biogeochemical cycles are crucial in this mechanism, connecting long-term geological cycles and the much faster evolution of the Earth’s outer envelopes. A small set of microbial-encoded proteins containing a redox-sensitive transition metal as their core catalytic center carry out the majority of the key biogeochemical reactions. Metals such as Fe, Co, Ni, Zn, Mo, Mn, W, V, and Cu are used in these proteins to access diverse redox couples as a function of what the planet has provided to biology over time. Despite the importance of this process, the relationship between metal availability and metabolism evolution and diversity has not been investigated in detail. COEVOLVE will elucidate the impact of transition metal availability on microbial functional diversity in deep time, combining fieldwork, laboratory experiments, and computational approaches. COEVOLVE will: 1) investigate the relationship between the availability of trace metals and microbial functional diversity in extant ecosystems and organisms; 2) link metabolic diversity and metal availability to different geological, geochemical, and mineralogical conditions; 3) link metabolic diversity and dependence on metal availability to the emergence and evolution of different metabolisms; and 4) determine the timing of major steps in metabolic evolution and link them to geochemical proxies of planetary surface redox change. Understanding the role of trace metal environmental distribution and availability in influencing microbial functional diversity might hold the key to understanding the co-evolution of life and our planet, unlocking a number of important discoveries at the core of diverse fields such as earth sciences, astrobiology, microbial ecology, and biotechnology.