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On the low‐frequency electrical polarization of bacterial cells in sands
Author(s) -
Ntarlagiannis Dimitrios,
Yee Nathan,
Slater Lee
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl024751
Subject(s) - shewanella putrefaciens , polarization (electrochemistry) , biophysics , materials science , concentration polarization , chemistry , analytical chemistry (journal) , environmental chemistry , geology , bacteria , membrane , biology , biochemistry , paleontology
We performed electrical measurements on sands flushed with bacterial suspensions of varying concentration. The first experiment was conducted with Shewanella putrefaciens (biomass 0–0.5 mg/L) and the second with Escherichia coli (biomass 0–42 mg/L). We measured a biomass‐dependent low‐frequency (10 Hz) polarization. At cell density <12 mg/L polarization decreased (up to 60 %) relative to before introduction of cells; the decrease was greater when the sand was artificially Fe‐coated to enhance the affinity of cells to the mineral surface. At cell density >12 mg/L polarization increased (up to 15%). We attribute the decrease in polarization at low cell density to alteration of the mineral‐fluid interface due to mineral‐cell interactions. The polarization enhancement at higher cell density is possibly a pore throat mechanism resulting from decreased ionic mobility and/or electron transfer due to cell accumulation in pores.