Role of menaquinone in the reduction of fumarate, nitrate, iron(III) and manganese(IV) by Shewanella putrefaciens MR-1

Authors

  • Charles R. Myers,

    Corresponding author
    1. Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertwon Plank Rd., Milwaukee, WI 53226, USA
      *Corresponding author. Tel: (414) 257 8593; Fax: (414) 778 4289.
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  • Judith M. Myers

    1. Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertwon Plank Rd., Milwaukee, WI 53226, USA
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*Corresponding author. Tel: (414) 257 8593; Fax: (414) 778 4289.

Abstract

Abstract Mutants of Shewanella putrefaciens MR-1 deficient in menaquinone and methylmenaquinone, but which have wild-type levels of ubiquinone, retain the ability to use trimethylamine N-oxide as an electron acceptor, but they lose the ability to use nitrate, iron(III), and fumarate as electron acceptors. These mutants also show a reduced rate of manganese(IV) reduction. One of these mutants could be restored to essentially wild-type phenotype by supplementing the medium with 1,4-dihydroxy-2-naphthoic acid. A requirement for naphthoquinones in iron(III) reduction and a preference for naphthoquinones in manganese(IV) reduction provide further support that the metal reducing systems in MR-1 are linked to anaerobic respiration.

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