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Photomixotrophic growth of Rhodobacter capsulatus SB1003 on ferrous iron

Kopf, S. H. and Newman, D. K. (2012) Photomixotrophic growth of Rhodobacter capsulatus SB1003 on ferrous iron. Geobiology, 10 (3). pp. 216-222. ISSN 1472-4677. PMCID PMC4587904.

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This study investigates the role iron oxidation plays in the purple non-sulfur bacterium Rhodobacter capsulatus SB1003. This organism is unable to grow photoautotrophically on unchelated ferrous iron [Fe(II)] despite its ability to oxidize chelated Fe(II). This apparent paradox was partly resolved by the discovery that SB1003 can grow photoheterotrophically on the photochemical breakdown products of certain ferric iron–ligand complexes, yet whether it could concomitantly benefit from the oxidation of Fe(II) to fix CO_2 was unknown. Here, we examine carbon fixation by stable isotope labeling of the inorganic carbon pool in cultures growing phototrophically on acetate with and without Fe(II). We show that R. capsulatus SB1003, an organism formally thought incapable of phototrophic growth on Fe(II), can actually harness the reducing power of this substrate and grow photomixotrophically, deriving carbon both from organic sources and from fixation of inorganic carbon. This suggests the possibility of a wider occurrence of photoferrotrophy than previously assumed.

Item Type:Article
Related URLs:
URLURL TypeDescription CentralArticle
Kopf, S. H.0000-0002-2044-0201
Newman, D. K.0000-0003-1647-1918
Additional Information:© 2011 Blackwell Publishing Ltd. Received 19 April 2011; accepted 16 November 2011. Article first published online: 29 Dec. 2011. We thank Alexandre Poulain for teaching S.K. how to work with R. capsulatus and Alexa Price-Whelan and other members of the Newman Lab for stimulating discussions. Three anonymous reviewers are gratefully acknowledged for constructive criticism. This work was supported by grants to D.K.N. from the National Science Foundation (grant MCB- 0616323) and the Howard Hughes Medical Institute. D.K.N. is an Investigator of the Howard Hughes Medical Institute.
Funding AgencyGrant Number
Howard Hughes Medical Institute (HHMI)UNSPECIFIED
Issue or Number:3
PubMed Central ID:PMC4587904
Record Number:CaltechAUTHORS:20120507-075239308
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Official Citation:KOPF, S. H. and NEWMAN, D. K. (2012), Photomixotrophic growth of Rhodobacter capsulatus SB1003 on ferrous iron. Geobiology, 10: 216–222. doi: 10.1111/j.1472-4669.2011.00313.x
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:31320
Deposited By: Tony Diaz
Deposited On:08 May 2012 16:28
Last Modified:09 Mar 2020 13:18

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