HR: 0801h
AN: NS11B-0498    [Abstracts]
TI: Electrical potentials associated with Microbial Activity in a Winogradsky Column
AU: * Singh, K
EM: ksingh03@qub.ac.uk
AF: Queen's University Belfast, Stranmillis Road, Belfast, BT9 5AG, United Kingdom
AU: Doherty, R
EM: r.doherty@qub.ac.uk
AF: Queen's University Belfast, Stranmillis Road, Belfast, BT9 5AG, United Kingdom
AU: Ntarlagiannis, D
EM: d.ntarlagiannis@qub.ac.uk
AF: Queen's University Belfast, Stranmillis Road, Belfast, BT9 5AG, United Kingdom
AU: Elliot, T
EM: t.elliot@qub.ac.uk
AF: Queen's University Belfast, Stranmillis Road, Belfast, BT9 5AG, United Kingdom
AB: Abstract: Electrical Potential (EP) measurements using Ag-AgCl electrodes have been conducted in a 1-D column containing a complex of sulphate-reducing microbial communities. The Winogradksky column design, typically used to study the microbial diversity of photoautotrophic anaerobes, represents in the laboratory a model biogeochemical soil-water interface. Once the bacterial communities in the column begin to grow dissolved oxygen content decreases downwards; an H2S gradient, produced by Sulphate Reducing Bacteria (SRB) develops in the anaerobic sediment at the base of the column, increases. These two gradients, acting in opposite directions, then create a range of habitats for a variety of microorganisms. The results presented here show EP data monitored over a period of 10 months at several points in the column during the establishment and evolution of the microbial niches, along with certain dissolved gases (O2, CO2, and H2S). The interpretation of EP data and analysis of gases produced in the column due biogeochemical activities show that it is possible to monitor and identify several states of microbial activity that could be inferred as a series of microbially mediated electron acceptors. Thus, overall, the EP observations show that Ag-AgCl electrodes have potential to be used to monitor the activities of biofilm growth in complex environments. Although the EP response may not reflect necessarily the ‘true' geophysical response of microbial activity but a galvanic reaction mediated by microbes or caused by the by-products produced during biofilm growth, nevertheless EP still has its uses in the non-invasive monitoring of environmental and microbial systems coupled with other geophysical techniques.
DE: 0416 Biogeophysics
DE: 0418 Bioremediation
SC: Near-Surface Geophysics [NS]
MN: 2007 Fall Meeting