Relationship between surface chemistry, biofilm structure, and electron transfer in Shewanella anodes.
A better understanding of how anode surface properties affect growth, development, and activity of electrogenic biofilms has great potential to improve the performance of bioelectrochemical systems such as microbial fuel cells. The aim of this paper was to determine how anodes with specific exposed functional groups (-N(CH3)3 (+), -COOH, -OH, and -CH3), created using ω-substituted alkanethiolates self-assembled monolayers attached to gold, affect the surface properties and functional performance of electrogenic Shewanella oneidensis MR-1 biofilms. A combination of spectroscopic, microscopic, and electrochemical techniques was used to evaluate how electrode surface chemistry influences morphological, chemical, and functional properties of S. oneidensis MR-1 biofilms, in an effort to develop improved electrode materials and structures. Positively charged, highly functionalized, hydrophilic surfaces were beneficial for growth of uniform biofilms with the smallest cluster sizes and intercluster diffusion distances, and yielding the most efficient electron transfer. The authors derived these parameters based on 3D morphological features of biofilms that were directly linked to functional properties of the biofilm during growth and that, during polarization, were directly connected to the efficiency of electron transfer to the anode. Our results indicate that substratum chemistry affects not only primary attachment, but subsequent biofilm development and bacterial physiology.
Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131.
Kateryna
K
Artyushkova
Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131.
Jose A
JA
Cornejo
Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131.
Linnea K
LK
Ista
Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131.
Sofia
S
Babanova
Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131.
Carlo
C
Santoro
Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131.
Plamen
P
Atanassov
Department of Civil Engineering, The University of New Mexico, Albuquerque, New Mexico 87131.
Andrew J
AJ
Schuler
D001674:Bioelectric Energy Sources; D018441:Biofilms / Q000254:growth & development*; D004560:Electricity; D055664:Electrochemical Techniques; D004566:Electrodes / Q000382:microbiology*; D008853:Microscopy; D020592:Shewanella / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D013057:Spectrum Analysis; D013499:Surface Properties