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Single‐cell determination of iron content in magnetotactic bacteria: implications for the iron biogeochemical cycle
Author(s) -
Amor Matthieu,
Tharaud Mickaël,
Gélabert Alexandre,
Komeili Arash
Publication year - 2020
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.14708
Subject(s) - biogeochemical cycle , magnetotactic bacteria , biology , environmental chemistry , bacteria , microorganism , siderophore , inductively coupled plasma mass spectrometry , intracellular , flux (metallurgy) , mass spectrometry , biochemistry , chemistry , ecology , chromatography , genetics , organic chemistry
Summary Magnetotactic bacteria (MTB) are ubiquitous aquatic microorganisms that mineralize dissolved iron into intracellular magnetic crystals. After cell death, these crystals are trapped into sediments that remove iron from the soluble pool. MTB may significantly impact the iron biogeochemical cycle, especially in the ocean where dissolved iron limits nitrogen fixation and primary productivity. A thorough assessment of their impact has been hampered by a lack of methodology to measure the amount of, and variability in, their intracellular iron content. We quantified the iron mass contained in single MTB cells of Magnetospirillum magneticum strain AMB‐1 using a time‐resolved inductively coupled plasma‐mass spectrometry methodology. Bacterial iron content depends on the external iron concentration, and reaches a maximum value of ~10 −6 ng of iron per cell. From these results, we calculated the flux of dissolved iron incorporation into environmental MTB populations and conclude that MTB may mineralize a significant fraction of dissolved iron into crystals.