Origin of microbial biomineralization and magnetotaxis during the Archean

Abstract

Microbes that synthesize minerals, a process known as microbial biomineralization, contributed substantially to the evolution of current planetary environments through numerous important geochemical processes. Despite its geological significance, the origin and evolution of microbial biomineralization remain poorly understood. Through combined metagenomic and phylogenetic analyses of deep-branching magnetotactic bacteria from the Nitrospirae phylum, and using a Bayesian molecular clock-dating method, we show here that the gene cluster responsible for biomineralization of magnetosomes, and the arrangement of magnetosome chain(s) within cells, both originated before or near the Archean divergence between the Nitrospirae and Proteobacteria. This phylogenetic divergence occurred well before the Great Oxygenation Event. Magnetotaxis likely evolved due to environmental pressures conferring an evolutionary advantage to navigation via the geomagnetic field. Earth's dynamo must therefore have been sufficiently strong to sustain microbial magnetotaxis in the Archean, suggesting that magnetotaxis coevolved with the geodynamo over geological time.Archean | microbial biomineralization | magnetotaxis | magnetotactic bacteria | geodynamo

Magnetosome magnetite biomineralization in a flagellated protist: evidence for an early evolutionary origin for magnetoreception in eukaryotes

“…Recently, Lin and colleagues () proposed that magnetotaxis in MTB developed during the Archean, suggesting that magnetoreception and the Earth's magnetic field evolved together over time. Understanding the origin and evolution of magnetoreception is clearly important in understanding mechanisms of magnetoreception currently utilized by organisms and possibly to predict future developments in this area, especially in view of the recent unexpected changes in Earth's magnetic field (Witze, ).…”

Single‐cell determination of iron content in magnetotactic bacteria: implications for the iron biogeochemical cycle

“…In sediments or water column, MTB are markers of oxic/anoxic transition zones (OATZ) where the concentration of dissolved iron is at its maximum (Kopp and Kirschvink, 2008;Lefèvre and Bazylinski, 2013). MTB have been proposed to represent some of the most ancient organisms capable of biomineralization, with an origin dating back to at least 3 Ga (Lin et al, 2017). Although MTB are ubiquitous on Earth, their impact on the past and modern biogeochemical cycling of metallic elements is still poorly constrained.…”

Identification of novel species of marine magnetotactic bacteria affiliated with Nitrospirae phylum

“…Being one of the deep-branching MTB group, Nitrospirae MTB plays an important role when analysing the origin and evolution of magnetosome biomineralization and magnetotaxis. Lin et al suggested that the magnetosome biomineralization and magnetotaxis was present before the separation of the Nitrospirae and Proteobacteria phyla, which was between~3.38 and 3.21 Ga (Lin et al, 2017b). However, it remains unclear whether the acquisition of magnetosome island (MAI), that encodes essential proteins for magnetosome biosynthesis in the genome, occurred before or after the divergence between freshwater and marine Nitrospirae MTB.…”