Biogeochemical fingerprinting of magnetotactic bacterial magnetite
- Univ. of Alabama, Tuscaloosa, AL (United States)
- Univ. of Granada (Spain)
- Ames Lab., Ames, IA (United States)
- Univ. of Nevada, Las Vegas, NV (United States)
Biominerals are important archives of the presence of life and environmental processes in the geological record. However, ascribing a clear biogenic nature to minerals with nanometer-sized dimensions has proven challenging. Identifying hallmark features of biologically controlled mineralization is particularly important for the case of magnetite crystals, resembling those produced by magnetotactic bacteria (MTB), which have been used as evidence of early prokaryotic life on Earth and in meteorites. In this work, we show that magnetite produced by MTB displays a clear coupled C–N signal that is absent in abiogenic and/or biomimetic (protein-mediated) nanometer-sized magnetite. We attribute the presence of this signal to intracrystalline organic components associated with proteins involved in magnetosome formation by MTB. These results demonstrate that we can assign a biogenic origin to nanometer-sized magnetite crystals, and potentially other biominerals of similar dimensions, using unique geochemical signatures directly measured at the nanoscale. This finding is significant for searching for the earliest presence of life in the Earth’s geological record and prokaryotic life on other planets.
- Research Organization:
- Ames Laboratory (AMES), Ames, IA (United States)
- Sponsoring Organization:
- National Science Foundation (NSF); USDOE Office of Science (SC)
- Grant/Contract Number:
- AC02-07CH11358
- OSTI ID:
- 1881905
- Report Number(s):
- IS-J--10,862; EAR-1647012; EAR-150779; EAr-1423939; CGL-2013-46612; CGL-2016-76723
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 31 Vol. 119; ISSN 0027-8424
- Publisher:
- National Academy of SciencesCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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