CaltechAUTHORS
  A Caltech Library Service

Isolation and Characterization of a Genetically Tractable Photoautotrophic Fe(II)-Oxidizing Bacterium, Rhodopseudomonas palustris Strain TIE-1

Jiao, Yongqin and Kappler, Andreas and Croal, Laura R. and Newman, Dianne K. (2005) Isolation and Characterization of a Genetically Tractable Photoautotrophic Fe(II)-Oxidizing Bacterium, Rhodopseudomonas palustris Strain TIE-1. Applied and Environmental Microbiology, 71 (8). pp. 4487-4496. ISSN 0099-2240. http://resolver.caltech.edu/CaltechAUTHORS:JIAaem05

[img]
Preview
PDF
See Usage Policy.

473Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:JIAaem05

Abstract

We report the isolation and characterization of a phototrophic ferrous iron [Fe(II)]-oxidizing bacterium named TIE-1 that differs from other Fe(II)-oxidizing phototrophs in that it is genetically tractable. Under anaerobic conditions, TIE-1 grows photoautotrophically with Fe(II), H2, or thiosulfate as the electron donor and photoheterotrophically with a variety of organic carbon sources. TIE-1 also grows chemoheterotrophically in the dark. This isolate appears to be a new strain of the purple nonsulfur bacterial species Rhodopseudomonas palustris, based on physiological and phylogenetic analysis. Fe(II) oxidation is optimal at pH 6.5 to 6.9. The mineral products of Fe(II) oxidation are pH dependent: below pH 7.0 goethite ({alpha}-FeOOH) forms, and above pH 7.2 magnetite (Fe3O4) forms. TIE-1 forms colonies on agar plates and is sensitive to a variety of antibiotics. A hyperactive mariner transposon is capable of random insertion into the chromosome with a transposition frequency of ~10–5. To identify components involved in phototrophic Fe(II) oxidation, mutants of TIE-1 were generated by transposon mutagenesis and screened for defects in Fe(II) oxidation in a cell suspension assay. Among approximately 12,000 mutants screened, 6 were identified that are specifically impaired in Fe(II) oxidation. Five of these mutants have independent disruptions in a gene that is predicted to encode an integral membrane protein that appears to be part of an ABC transport system; the sixth mutant has an insertion in a gene that is a homolog of CobS, an enzyme involved in cobalamin (vitamin B12) biosynthesis.


Item Type:Article
Additional Information:Copyright © 2005, American Society for Microbiology. Received 10 December 2004/ Accepted 11 March 2005 We are indebted to Randall E. Mielke for TEM imaging and Elizabeth A. Ottesen for help in constructing the 16S phylogenetic tree. We thank Arash Komeili and Jeff Gralnick for guidance throughout this study and all the Newman lab members for helpful discussions. This work was supported by a grant from the Packard Foundation to D.K.N. and a postdoctoral fellowship from the German Research Foundation to A.K.
Record Number:CaltechAUTHORS:JIAaem05
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:JIAaem05
Alternative URL:http://dx.doi.org/10.1128/AEM.71.8.4487-4496.2005
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1822
Collection:CaltechAUTHORS
Deposited By: Archive Administrator
Deposited On:19 Feb 2006
Last Modified:26 Dec 2012 08:46

Repository Staff Only: item control page