Bacterial Nanowires
Encyclopedia
Bacterial nanowires are electrically conductive appendages produced by a number of bacteria
most notably from (but not exclusive to) the Geobacter
and Shewanella
genera. Conductive nanowires have also been confirmed in the oxygenic cyanobacterium Synechocystis PCC6803 and a thermophilic, methanogenic coculture consisting of Pelotomaculum thermopropionicum and Methanothermobacter thermoautotrophicus.
use nanowires to transfer electrons to extracellular electrical acceptors (such as Fe(III) oxides). This function was discovered through the examination of mutants, whose pili could attach to the iron, but would not reduce it.
Additionally, Nanowires can facilitate long-range electron transfer across thick biofilm layers . By connecting to other cells above them, pili allow bacteria located in anoxic conditions to still use oxygen as their terminal electron acceptor. For example, organisms in the genus Shewanella
have been observed to form electrically conductive pili in response to electron-acceptor limitation.
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
most notably from (but not exclusive to) the Geobacter
Geobacter
Geobacter is a genus of proteobacteria. Geobacter are an anaerobic respiration bacterial species which have capabilities that make them useful in bioremediation...
and Shewanella
Shewanella
Shewanella is the sole genus included in the Shewanellaceae family of marine bacteria. Shewanella is a marine bacterium capable of modifying metals, by saturating them with electrons causing the metal to expand and soften, allowing them to process it, which in turn releases an electrical charge...
genera. Conductive nanowires have also been confirmed in the oxygenic cyanobacterium Synechocystis PCC6803 and a thermophilic, methanogenic coculture consisting of Pelotomaculum thermopropionicum and Methanothermobacter thermoautotrophicus.
Physiology
Nanowires are modified pili, which are used to establish connections to terminal electron acceptors. Species of the genus GeobacterGeobacter
Geobacter is a genus of proteobacteria. Geobacter are an anaerobic respiration bacterial species which have capabilities that make them useful in bioremediation...
use nanowires to transfer electrons to extracellular electrical acceptors (such as Fe(III) oxides). This function was discovered through the examination of mutants, whose pili could attach to the iron, but would not reduce it.
Additionally, Nanowires can facilitate long-range electron transfer across thick biofilm layers . By connecting to other cells above them, pili allow bacteria located in anoxic conditions to still use oxygen as their terminal electron acceptor. For example, organisms in the genus Shewanella
Shewanella
Shewanella is the sole genus included in the Shewanellaceae family of marine bacteria. Shewanella is a marine bacterium capable of modifying metals, by saturating them with electrons causing the metal to expand and soften, allowing them to process it, which in turn releases an electrical charge...
have been observed to form electrically conductive pili in response to electron-acceptor limitation.