It is unknown to which extent phototrophic Fe(II) oxidation takes place in the simultaneous presence of organic electron donors (e.g., acetate/lactate). Therefore, the photoferrotrophic strain Rhodopseudomonas palustris TIE-1 was inoculated with various combinations of Fe(II), acetate and lactate to understand metabolic substrate preference. When acetate was provided together with Fe(II), TIE-1 consumed acetate first before Fe(II). When provided lactate plus Fe(II), TIE-1 consumed both substrates in parallel. When all three substrates were provided in one culture, TIE-1 used all substrates simultaneously. Our study suggests that the availability of alternative electron donors in addition to ferrous iron limits phototrophic iron oxidation.
Bibliographical noteFunding Information:
This study was funded by a grant from the Deutsche For-schungsgemeinschaft (DFG) to A.K. (KA1736/16-1), a Marie Curie ERG grant to C.S. (PERF04-GA-2008-239252) and a Landesgraduiertenfo€rderung fellowship to E.D.M. (Gz l 1.2_7631.2/Melton).
- carbon flow
- iron redox cycling
- phototrophic Fe(II) oxidation