Conjugated Oligoelectrolytes Increase Power Generation in E. coli Microbial Fuel Cells

Abstract

A series of conjugated oligoelectrolytes with structural variations is used to stain E. coli. By taking advantage of a high-throughput screening platform that incorporates gold anodes, it is found that MFCs with COE-modified E. coli generate significantly higher power densities, relative to unmodified E. coli. These findings highlight the potential of using water-soluble molecules inspired by the work on organic semiconductors to improve electrode/microbe interfaces.

Membrane permeabilization by conjugated oligoelectrolytes accelerates whole-cell catalysis

“…21,27 In contrast to previous reports, the IM remains primarily intact under our experimental conditions. 9 Since the conditions described herein closely mimic that used in MFCs, it is unlikely that the increased extracellular electron transfer (EET) in MFCs is due to cell lysis.…”

“…45%. Given that the DSSN+ exposure in these experiments do not cause measurable cytotoxicity, 10,21,22 these data indicate DSSN+ is able to increase OM permeability without signicantly altering E. coli cell viability. These observations demonstrate that scenario (i), namely enzyme transport across the OM, is accelerated for cells that are treated with DSSN+.…”

“…10,15,21,22 Despite its utility, the origin of DSSN+ improvement in bioelectrochemical devices remains under debate. 9,10,17,21,[23][24][25][26][27][28][29][30] Model membrane studies have shown that COEs increase ion conductance across the membrane. 13 To add to mechanistic complexity, recent results suggest that COEs may interact with other components in the cell envelope, such as lipopolysaccharides and cholic acid.…”

Oligopolyphenylenevinylene-Conjugated Oligoelectrolyte Membrane Insertion Molecules Selectively Disrupt Cell Envelopes of Gram-Positive Bacteria

“…DSSNϩ, 1,4-bis(4Љ-(N,N-bis(6ЉЉ-(N,N,N-trimethylammonium)hexyl)amino)-styryl)benzene tetraiodide (DSBNϩ), and 1,4-bis(4Љ-(N,N-bis(6ЉЉ-(N,N,N-trimethylammonium)hexyl)amino)-styryl)-2,3,5,6 tetrafluorobenzene tetraiodide (4F-DSBNϩ) were synthesized as reported previously (2,11). The MIMs used in this study were selected because their biotechnological potential had been demonstrated previously in bioelectrochemical systems and because interesting interactions with microbial cells have been documented (1,3,10).…”

“…In this contribution, we examine the response of selected Gram-negative and Gram-positive organisms to three OPV-COE MIMs that have been the focus of previous studies (1,3,9,10). Furthermore, using a combination of specific deletion mutants along with a model membrane system, we will explore interactions between OPV-COEs and different components of the cellular envelope.…”