Diversity of promoter elements in a Geobacter sulfurreducens mutant adapted to disruption in electron transfer

  • Julia Krushkal
  • Ching Leang
  • Jose F. Barbe
  • Yanhua Qu
  • Bin Yan
  • Marko Puljic
  • Ronald M. Adkins
  • Derek R. Lovley
Review

DOI: 10.1007/s10142-008-0094-7

Cite this article as:
Krushkal, J., Leang, C., Barbe, J.F. et al. Funct Integr Genomics (2009) 9: 15. doi:10.1007/s10142-008-0094-7

Abstract

The delta-proteobacterium, Geobacter sulfurreducens, can obtain energy by coupling the oxidation of organic matter to the reduction of insoluble Fe(III) or the anode of a microbial fuel cell. Because Fe(III) oxide or the anode surface, in contrast to oxygen, nitrate, or sulfate, is not soluble nor can it be reduced readily, Geobacter species have developed mechanisms which allow electrons to be delivered across outer membrane to the cell surface. OmcB is an outer-membrane c-type cytochrome important for G. sulfurreducens Fe(III) respiration. In the absence of OmcB, cells lost the ability to reduce soluble or insoluble Fe(III). However, the omcB deletion mutant can slowly adapt to growth on soluble Fe(III) over prolonged incubation in the medium with acetate as the electron donor. We discuss available information about predicted or experimentally validated promoters and transcription regulatory sites identified upstream of operons with transcriptional expression significantly changed in the adapted omcB mutant. DNA sequences of upstream regions of coregulated operons in the adapted mutant are divergent, suggesting the presence of recognition sites for different transcriptional regulators and indicating that adaptation of the omcB mutant to growth on soluble Fe(III) has shifted the relevant expression networks involved to a more diverse molecular basis.

Keywords

Geobacter sulfurreducens Promoter c-type cytochrome Transcription 

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Julia Krushkal
    • 1
  • Ching Leang
    • 3
  • Jose F. Barbe
    • 1
  • Yanhua Qu
    • 1
  • Bin Yan
    • 1
    • 2
  • Marko Puljic
    • 1
  • Ronald M. Adkins
    • 4
  • Derek R. Lovley
    • 3
  1. 1.Department of Preventive MedicineUniversity of Tennessee Health Science CenterMemphisUSA
  2. 2.NIDCDNational Institutes of HealthBethesdaUSA
  3. 3.Department of Microbiology, Morrill Science Center IV NorthUniversity of MassachusettsAmherstUSA
  4. 4.Department of PediatricsUniversity of Tennessee Health Science CenterMemphisUSA

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