biostudies-literatureKeffer JLHHS | National Institutes of HealthHHS | National Institutes of Health (NIH)National Science Foundation (NSF)NIGMS NIH HHSNational Science Foundatione0186524https://www.ebi.ac.uk/biostudies/studies/S-EPMC12016527biostudies-literatureUnknown91(4)Most of Earth's iron is mineral-bound, but it is unclear how and to what extent iron-oxidizing microbes can use solid minerals as electron donors. A prime candidate for studying mineral-oxidizing growth and pathways is <i>Sideroxydans lithotrophicus</i> ES-1, a robust, facultative iron oxidizer with multiple possible iron oxidation mechanisms. These include Cyc2 and Mto pathways plus other multiheme cytochromes and cupredoxins, and so we posit that the mechanisms may correspond to different Fe(II) sources. Here, <i>S. lithotrophicus</i> ES-1 was grown on dissolved Fe(II)-citrate and magnetite. <i>S. lithotrophicus</i> ES-1 oxidized all dissolved Fe²⁺ released from magnetite and continued to build biomass when only solid Fe(II) remained, suggesting it can utilize magnetite as a sApplied and environmental microbiologyMicrobial magnetite oxidation via MtoAB porin-multiheme cytochrome complex in &lt;i&gt;Sideroxydans lithotrophicus&lt;/i&gt; ES-1.PMC12016527P20 GM103446P20 GM104316P20GM104316P20GM103446BIO-1817651Zhou NRushworth DDKeffer JLChan CSYu YfalseMicrobial magnetite oxidation via MtoAB porin-multiheme cytochrome complex in &lt;i&gt;Sideroxydans lithotrophicus&lt;/i&gt; ES-1.Most of Earth's iron is mineral-bound, but it is unclear how and to what extent iron-oxidizing microbes can use solid minerals as electron donors. A prime candidate for studying mineral-oxidizing growth and pathways is <i>Sideroxydans lithotrophicus</i> ES-1, a robust, facultative iron oxidizer with multiple possible iron oxidation mechanisms. These include Cyc2 and Mto pathways plus other multiheme cytochromes and cupredoxins, and so we posit that the mechanisms may correspond to different Fe(II) sources. Here, <i>S. lithotrophicus</i> ES-1 was grown on dissolved Fe(II)-citrate and magnetite. <i>S. lithotrophicus</i> ES-1 oxidized all dissolved Fe²⁺ released from magnetite and continued to build biomass when only solid Fe(II) remained, suggesting it can utilize magnetite as a s2025-01-01T00:00:00Z2025 Apr2026-06-03T04:53:05.968Z2026-05-28T03:06:56.736ZS-EPMC120165274004227610.1128/aem.01865-24