Physical Sciences and Mathematics Commons^™

Microbial Nanowires: Is The Subsurface "Hardwired"?, Dimitrios Ntarlagiannis, Estella A. Atekwana, Eric A. Hill, Yuri A. Gorby

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Earth's shallow subsurface results from integrated biological, geochemical, and physical processes. Methods are sought to remotely assess these interactive processes, especially those catalysed by micro-organisms. Using saturated sand columns and the metal reducing bacterium Shewanella oneidensis MR-1, we show that electrically conductive appendages called bacterial nanowires are directly associated with electrical potentials. No significant electrical potentials were detectable in columns inoculated with mutant strains that produced non-conductive appendages. Scanning electron microscopy imaging revealed a network of nanowires linking cells-cells and cells to mineral surfaces, "hardwiring" the entire length of the column. We hypothesize that the nanowires serve as conduits …