Rapid detection of microbial cell abundance in aquatic systems.
The detection and quantification of naturally occurring microbial cellular densities is an essential component of environmental systems monitoring. While there are a number of commonly utilized approaches for monitoring microbial abundance, capacitance-based biosensors represent a promising approach because of their low-cost and label-free detection of microbial cells, but are not as well characterized as more traditional methods. Here, we investigate the applicability of enhanced alternating current electrokinetics (ACEK) capacitive sensing as a new application for rapidly detecting and quantifying microbial cellular densities in cultured and environmentally sourced aquatic samples. ACEK capacitive sensor performance was evaluated using two distinct and dynamic systems - the Great Australian Bight and groundwater from the Oak Ridge Reservation in Oak Ridge, TN. Results demonstrate that ACEK capacitance-based sensing can accurately determine microbial cell counts throughout cellular concentrations typically encountered in naturally occurring microbial communities (10(3)-10(6) cells/mL). A linear relationship was observed between cellular density and capacitance change correlations, allowing a simple linear curve fitting equation to be used for determining microbial abundances in unknown samples. This work provides a foundation for understanding the limits of capacitance-based sensing in natural environmental samples and supports future efforts focusing on evaluating the robustness ACEK capacitance-based within aquatic environments.
Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA; Department of Civil & Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USA.
Andrea M
AM
Rocha
Department of Electrical Engineering & Computer Science, University of Tennessee, Knoxville, TN 37996, USA.
Quan
Q
Yuan
Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
Dan M
DM
Close
Department of Civil & Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USA.
Kaela B
KB
O'Dell
Department of Civil & Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USA.
Julian L
JL
Fortney
Department of Electrical Engineering & Computer Science, University of Tennessee, Knoxville, TN 37996, USA.
Jayne
J
Wu
Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA; Department of Civil & Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USA; Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996, USA; Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA; Institute for a Secure & Sustainable Environment, University of Tennessee, Knoxville, TN 37996, USA. Electronic address: tchazen@utk.edu.
Terry C
TC
Hazen
D001419:Bacteria / Q000302:isolation & purification*; D015374:Biosensing Techniques / Q000191:economics / Q000379:methods*; D025802:Electric Capacitance; D060587:Groundwater / Q000382:microbiology; D012623:Seawater / Q000382:microbiology; D014871:Water Microbiology
AC electrokinetics; Biosensor; Interfacial capacitance; Microbial abundance