Both arsenic (As) and antimony (Sb) are commonly found as oxyanions and are subject to biologically-mediated redox reactions. Antimony-oxidizing bacteria oxidize antimonite (Sb(III)) to antimonate (Sb(V)) and, the reverse reaction can also be microbially catalyzed. Metalloid oxidation can support chemolithoautotrophic growth: As(III) or Sb(III) can serve as an electron donor to provide reducing equivalents for the fixation of CO2 into organic matter (Deng et al., 2021).