Electrically conductive pili from pilin genes of phylogenetically diverse microorganisms
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- David J F Walker
- Department of Microbiology, University of Massachusetts , Amherst, MA, USA
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- Ramesh Y Adhikari
- Department of Physics, University of Massachusetts , Amherst, MA, USA
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- Dawn E Holmes
- Department of Microbiology, University of Massachusetts , Amherst, MA, USA
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- Joy E Ward
- Department of Microbiology, University of Massachusetts , Amherst, MA, USA
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- Trevor L Woodard
- Department of Microbiology, University of Massachusetts , Amherst, MA, USA
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- Kelly P Nevin
- Department of Microbiology, University of Massachusetts , Amherst, MA, USA
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- Derek R Lovley
- Department of Microbiology, University of Massachusetts , Amherst, MA, USA
抄録
<jats:title>Abstract</jats:title> <jats:p>The possibility that bacteria other than Geobacter species might contain genes for electrically conductive pili (e-pili) was investigated by heterologously expressing pilin genes of interest in Geobacter sulfurreducens. Strains of G. sulfurreducens producing high current densities, which are only possible with e-pili, were obtained with pilin genes from Flexistipes sinusarabici, Calditerrivibrio nitroreducens and Desulfurivibrio alkaliphilus. The conductance of pili from these strains was comparable to native G. sulfurreducens e-pili. The e-pili derived from C. nitroreducens, and D. alkaliphilus pilin genes are the first examples of relatively long (>100 amino acids) pilin monomers assembling into e-pili. The pilin gene from Candidatus Desulfofervidus auxilii did not yield e-pili, suggesting that the hypothesis that this sulfate reducer wires itself with e-pili to methane-oxidizing archaea to enable anaerobic methane oxidation should be reevaluated. A high density of aromatic amino acids and a lack of substantial aromatic-free gaps along the length of long pilins may be important characteristics leading to e-pili. This study demonstrates a simple method to screen pilin genes from difficult-to-culture microorganisms for their potential to yield e-pili; reveals new sources for biologically based electronic materials; and suggests that a wide phylogenetic diversity of microorganisms may use e-pili for extracellular electron exchange.</jats:p>
収録刊行物
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- The ISME Journal
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The ISME Journal 12 (1), 48-58, 2017-09-05
Oxford University Press (OUP)