Magnetotactic bacteria (MTB) are ubiquitous aquatic microorganisms that incorporate iron from their environment to synthesize intracellular nanoparticles of magnetite (Fe₃O₄) or greigite (Fe₃S₄) in a genetically controlled manner. Magnetite and greigite magnetic phases allow MTB to swim towards redox transition zones where they thrive. MTB may represent some of the oldest microorganisms capable of synthesizing minerals on Earth and have been proposed to significantly impact the iron biogeochemical cycle by immobilizing soluble iron into crystals that subsequently fossilize in sedimentary rocks. In the present article, we describe the distribution of MTB in the environment and discuss the possible function of the magnetite and greigite nanoparticles. We then provide an overview of the chemical mechanisms leading to iron mineralization in MTB. Finally, we update the methods used for the detection of MTB crystals in sedimentary rocks and present their occurrences in the geological record.

中文翻译：

---

趋磁细菌中的铁生物矿化细胞器：在古代岩石样品中的功能，合成和保存。

趋磁细菌（MTB）是普遍存在的水生微生物，它们从周围环境吸收铁以合成磁铁矿（Fe ₃ O ₄）或钙铁矿（Fe ₃ S ₄）的细胞内纳米颗粒。）以基因控制的方式。磁铁矿和方铁矿磁性相使MTB朝着氧化还原过渡区畅游，在那里壮成长。MTB可能代表了一些能够在地球上合成矿物质的最古老的微生物，并且已经提出通过将可溶性铁固定在晶体中并随后在沉积岩中化石来显着影响铁的生物地球化学循环。在本文中，我们描述了MTB在环境中的分布，并讨论了磁铁矿和水铁矿纳米颗粒的可能功能。然后，我们概述了导致MTB中铁矿化的化学机理。最后，我们更新了用于检测沉积岩中MTB晶体的方法，并将其出现在地质记录中。