Melanin Production and Use as a Soluble Electron Shuttle for Fe(III) Oxide Reduction and as a Terminal Electron Acceptor by Shewanella algae BrY
Autor: | Charles E. Turick, Frank Caccavo, Louis S. Tisa |
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Rok vydání: | 2002 |
Předmět: |
Shewanella
Inorganic chemistry Oxide Electrons Shewanella algae engineering.material Ferric Compounds Applied Microbiology and Biotechnology Melanin Hydrous ferric oxides chemistry.chemical_compound Algae Melanins chemistry.chemical_classification integumentary system Ecology biology Electron acceptor biology.organism_classification Geomicrobiology Molecular Weight chemistry engineering Cytochromes Oxidation-Reduction Bacteria Hydrogen Food Science Biotechnology |
Zdroj: | Applied and Environmental Microbiology. 68:2436-2444 |
ISSN: | 1098-5336 0099-2240 |
Popis: | Dissimilatory metal-reducing bacteria (DMRB) utilize numerous compounds as terminal electron acceptors, including insoluble iron oxides. The mechanism(s) of insoluble-mineral reduction by DMRB is not well understood. Here we report that extracellular melanin is produced by Shewanella algae BrY. The extracted melanin served as the sole terminal electron acceptor. Upon reduction the reduced, soluble melanin reduced insoluble hydrous ferric oxide in the absence of bacteria, thus demonstrating that melanin produced by S. algae BrY is a soluble Fe(III)-reducing compound. In the presence of bacteria, melanin acted as an electron conduit to Fe(III) minerals and increased Fe(III) mineral reduction rates. Growth of S. algae BrY occurred in anaerobic minimal medium supplemented with melanin extracted from previously grown aerobic cultures of S. algae BrY. Melanin produced by S. algae BrY imparts increased versatility to this organism as a soluble Fe(III) reductant, an electron conduit for iron mineral reduction, and a sole terminal electron acceptor that supports growth. |
Databáze: | OpenAIRE |
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