北京高压科学研究中心
Center for High Pressure Science &Technology Advanced Research

P2-Lin Wei_abstract+photo

Ecophysiological significance of intracellular biomineralization in bacteria

Wei Lin*, Yongxin Pan

Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China

*weilin0408@gmail.com



Microbes that synthesize minerals, a process known as microbial biomineralization, contribute substantially to the evolution of current planetary environments. One of the most interesting examples of these types of organisms are the magnetotactic bacteria (MTB), a polyphyletic group of prokaryotes that form intracellular nano-sized iron minerals of magnetite (Fe3O4) and/or greigite (Fe3S4), known as magnetosomes. MTB play important roles in the geochemical cycling of iron, sulfur, nitrogen and carbon. They also represent an intriguing model system not just for the study of microbial biomineralization but also for magnetoreception, prokaryotic organelle formation and microbial biogeography.

We have conducted a large scale cultivation-independent survey of MTB across the Northern and Southern Hemispheres and have revealed an unexpected diversity of MTB. Interestingly, we found that MTB also exist in some extreme environments including the deep subseafloor and marine oxygen minimum zone, thereby extending our knowledge on their diversity and distribution. For decades MTB were thought only in the phyla Proteobacteria, Nitrospirae and Omnitrophica. However, we recently discovered two novel MTB populations belonging to the phyla Latescibacteria and Planctomycetes separately, suggesting that microorganims with the ability to biomineralize magnetosomes should be more diverse and ubiquitous than previously thought.

Through metagenomic and phylogenomic analyses we have found that magnetotaxis in the domain Bacteria is an ancient physiological trait that has a single common origin with lineage-specific evolution. MTB evolved during the mid-Archean (>3.0 Ga) and are one of the earliest magnetic-sensing and biomineralizing organisms on Earth. An ancient origin of MTB, and its persistence in multiple bacterial lineages since their divergence during Archean time, implies both temporal continuity of Earth’s dynamo and persistent environmental stratification.