Mj. Silva et Jl. Wong, ELECTROCHEMICAL BIOASSAY SYSTEM - REDOX MEASUREMENTS OF ESCHERICHIA-COLI GROWTH BY MULTICHANNEL ANALYZER, Bioelectrochemistry and bioenergetics, 34(2), 1994, pp. 177-184
The redox responses to growth of Escherichia coli, including potential
changes with and without current drain, peak current and coulombic ou
tput as a function of electrode surface area, and the lag time from in
oculation to mid-peak potential have been determined. Excellent reprod
ucibility was established for replicate experiments under the uniform
conditions prevailing in a multichannel electrochemical analyzer with
automatic data acquisition. Bacterial generation of hydrogen from gluc
ose followed by oxidation on the Pt anode appears to be the major elec
trode reaction. Concurrent measurements of absorbance and glucose cons
umption have been made, The following rate constants were obtained fro
m kinetic studies: k (glucose consumption), k (E. coli growth), k (pot
ential), k (current) and k (hydrogen generation). Further characteriza
tion of this bioelectrochemical system was derived from the studies of
increasing concentrations of glucose, E. coil adsorption to anode, si
mulating redox responses with gaseous hydrogen and peroxide inhibition
of the redox potential. Thus redox responses and kinetics measured in
an E. coli fuel cell can be used to compare dose responses to agents
and conditions that affect bacterial growth and environmental health.