Faculty Collaboration Database

Shewanella oneidensis MR-1 restores menaquinone synthesis to a menaquinone-negative mutant. Appl Environ Microbiol 2004 Sep;70(9):5415-25

Date

09/04/2004

Pubmed ID

15345428

Pubmed Central ID

PMC520873

DOI

10.1128/AEM.70.9.5415-5425.2004

Scopus ID

2-s2.0-4644245648 (requires institutional sign-in at Scopus site)   45 Citations

Abstract

The mechanisms underlying the use of insoluble electron acceptors by metal-reducing bacteria, such as Shewanella oneidensis MR-1, are currently under intensive study. Current models for shuttling electrons across the outer membrane (OM) of MR-1 include roles for OM cytochromes and the possible excretion of a redox shuttle. While MR-1 is able to release a substance that restores the ability of a menaquinone (MK)-negative mutant, CMA-1, to reduce the humic acid analog anthraquinone-2,6-disulfonate (AQDS), cross-feeding experiments conducted here showed that the substance released by MR-1 restores the growth of CMA-1 on several soluble electron acceptors. Various strains derived from MR-1 also release this substance; these include mutants lacking the OM cytochromes OmcA and OmcB and the OM protein MtrB. Even though strains lacking OmcB and MtrB cannot reduce Fe(III) or AQDS, they still release a substance that restores the ability of CMA-1 to use MK-dependent electron acceptors, including AQDS and Fe(III). Quinone analysis showed that this released substance restores MK synthesis in CMA-1. This ability to restore MK synthesis in CMA-1 explains the cross-feeding results and challenges the previous hypothesis that this substance represents a redox shuttle that facilitates metal respiration.

Author List

Myers CR, Myers JM

MESH terms used to index this publication - Major topics in bold

Electron Transport
Ferric Compounds
Fumarates
Iron
Kinetics
Nitrates
Oxidation-Reduction
Shewanella
Vitamin K 2