DNA Hybridization To Interface Current-Producing Cells with Electrode Surfaces

Abstract

As fossil fuels are increasingly linked to environmental damage, the development of renewable, affordable biological alternative fuels is vital. Shewanella oneidensis is often suggested as a potential component of bioelectrochemical cells because of its ability to act as an electron donor to metal surfaces. These microbes remain challenging to implement, though, due to inconsistency in biofilm formation on electrodes and therefore current generation. We have applied DNA hybridization-based cell adhesion to immobilize S. oneidensis on electrodes. High levels of current are reproducibly generated from these cell layers following only 30 min of immobilization without the need for the formation of a biofilm. Upon incorporation of DNA mismatches in the microbe immobilization sequence, significant attenuation in current production is observed, suggesting that at least part of the electron transfer to the electrode is DNA-mediated. This method of microbe assembly is rapid, reproducible, and facile for the production of anodes for biofuel cells.

Light-induced Patterning of Electroactive Bacterial Biofilms

“…Prior efforts to direct electroactive biofilm formation on surfaces have focused solely on engineering cell-electrode attachment, rather than patterning, through synthetic biology and materials engineering strategies. These works were based on either (I) enhancing biofilm formation by expressing adhesive appendages on cell surfaces 49,50 and increasing c-di-GMP levels 51,52 or (II) placing complementary chemical or DNA-based structures on substrates and cell surfaces to bond cells to electrodes [53][54][55][56][57] . Compared with these previous works, our strategy does not require electrode pretreatment for electroactive biofilm patterning and can generate robust biofilms with defined dimensions.…”

Engineering bacterial surface interactions using DNA as a programmable material

“…Dihydroxyl groups from surface polysaccharides can also be oxidized into active aldehyde groups for subsequent condensation reactions. 42,74 Alternatively, physical extrusion provides a non-covalent approach to directly encapsulate bacteria with different types of biocompatible materials, including erythrocyte 31 and yeast cell membranes, 32 bacterial self-produced biofilms, 75 and Ca 2+bridged lipid layers. 76 These coating materials cover and protect beneficial bacteria from environmental stress, endowing them with superior resistance and adhesion ability.…”

“…In 2018, they reported the fabrication of bacteria-coated electrodes using S. oneidensis cells, a type of electricity-generating bacteria. 42 The current density can be adjusted by tuning the DNA density on the electrode, which determined the number of bacterial cells attached on the electrode surface. A higher DNA density resulted in more cells, subsequently generating a high level of current.…”

“…Only several recent studies have been reported to develop synthetic approaches to incorporate DNA into bacteria. [39][40][41][42][43] The exploration of DNA nanotechnology on manipulating bacterial interactions and functions is actively proceeded but still in its infancy.…”

How Far Can Electromicrobial Production Go?

“…Recent efforts have been made to chemically engineer the abiotic-biotic interface in these systems, including through the introduction of deoxyribonucleic acid (DNA) hybridization-based cell adhesion to attach EAMs to electrodes. 8 Although significant progress has been made to understand the fundamental biology of electroactive cells and apply that knowledge to EMP, EET-EMP technologies remain limited to proof-of-concept systems.…”