[Characterization of membrane-bound Fe(III)-EDTA reductase activities of the thermophilic gram-positive dissimilatory iron-reducing bacterium Thermoterrabacterium ferrireducens].

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Title[Characterization of membrane-bound Fe(III)-EDTA reductase activities of the thermophilic gram-positive dissimilatory iron-reducing bacterium Thermoterrabacterium ferrireducens].
Publication TypeJournal Article
Year of Publication2007
AuthorsGavrilov, SN, Slobodkin, AI, Robb, FT, de Vries, S
JournalMikrobiologiia
Volume76
Issue2
Pagination164-71
Date Published2007 Mar-Apr
ISSN0026-3656
KeywordsBacterial Proteins, Cell Membrane, Chromatography, Ion Exchange, Citrates, Cytochromes c, Detergents, Edetic Acid, Ferric Compounds, Glucosides, Glycerol, Gram-Positive Bacteria, Iron, Molecular Weight, Oxidation-Reduction, Oxidoreductases, Solubility
Abstract

Whole-cell suspensions of T. ferrireducens reduced Fe(III) citrate, Fe(III)-EDTA, and ferrihydrite with glycerol as an electron donor. After cell disruption, the highest activity was registered with Fe(III)-EDTA as the electron acceptor and NADH or NAD(P)H as electron donors. About 80% of the NAD(P)H-dependent Fe(III)-EDTA reductase activities were associated with the membrane fraction of the cells. Treatment of the membranes with lauryl maltoside led to complete solubilization of the NADH-dependent and 70% solubilization of the NADPH-dependent Fe(III)-EDTA reductase activities. After purification by ion-exchange chromatography, the NADH-dependent activity was concentrated 8-fold, and the NADPH-dependent activity was concentrated 11-fold, with a yield of about 10% for both activities. The Fe(III)-EDTA-reducing enzyme complex included c-type cytochromes and a protein with a molecular mass of ca. 115 k Da, consisting of two polypeptides. This is the first description of membrane-bound Fe(III)-reducing oxidoreductase activities from a gram-positive dissimilatory Fe(III)-reducing bacterium.

Alternate JournalMikrobiologiia
PubMed ID17583211