Micromagnetic calculation of the magnetite magnetosomal morphology control of magnetism in magnetotactic bacteria

作者：Zhaowen Pei, Liao Chang, Fan Bai, R. J. Harrison · 发表于：Journal of The Royal Society Interface · 年份：2023 · DOI：10.1098/rsif.2023.0297 · 被引用次数：10 · 研究领域：Geomagnetism and Paleomagnetism Studies、Geology and Paleoclimatology Research、Magnetic and Electromagnetic Effects

Magnetotactic bacteria (MTB), which precisely bio-synthesize magnetosomes of magnetite or greigite nanoparticles, have attracted broad interdisciplinary interests in microbiology, magnetic materials, biotechnology and geobiology. Previous experimental and numerical investigations demonstrate a close link among MTB species, magnetosome crystal habits, and magnetic characteristics, but quantitative constraints are currently lacking. In this study, we build three-dimensional finite-element micromagnetic models of intact magnetosome chains in common MTB species and corresponding collapsed chains. Realistic numerical microstructures were constructed for the three typical biogenic magnetite crystal forms-cuboctahedron, prism and bullet. Our calculations reveal characteristic magnetic properties associated with specific magnetite crystal forms and MTB species. Cuboctahedron and bullet crystals show distinct low coercivity (less than 30 mT) and high coercivity (greater than 50 mT) clusters, respectively. Prismatic crystals have a broad range of hysteresis parameters that are strongly controlled by chain structure. This magnetic property clustering, combined with magnetic unmixing methods and electron microscopy observations, can fingerprint biogenic magnetite components in geological and environmental samples. The passive magnetic orientation efficiency of various magnetosome chains was calculated. Some bullet-shaped magnetosome chains have higher magnetic moments than those with cub...