Towards patterned bioelectronics: facilitated immobilization of exoelectrogenic Escherichia coli with heterologous pili

Abstract

SummaryBiosensors detect signals using biological sensing components such as redox enzymes and biological cells. Although cellular versatility can be beneficial for different applications, limited stability and efficiency in signal transduction at electrode surfaces represent a challenge. Recent studies have shown that the Mtr electron conduit from Shewanella oneidensis MR‐1 can be produced in Escherichia coli to generate an exoelectrogenic model system with well‐characterized genetic tools. However, means to specifically immobilize this organism at solid substrates as electroactive biofilms have not been tested previously. Here, we show that mannose‐binding Fim pili can be produced in exoelectrogenic E. coli and can be used to selectively attach cells to a mannose‐coated material. Importantly, cells expressing fim genes retained current production by the heterologous Mtr electron conduit. Our results demonstrate the versatility of the exoelectrogenic E. coli system and motivate future work that aims to produce patterned biofilms for bioelectronic devices that can respond to various biochemical signals.

Microbial reduction of metal-organic frameworks enables synergistic chromium removal

“…3). Unlike S. oneidensis , E. coli does not readily establish biofilms on redox-active surfaces 48 . While growth dynamics were not continuously monitored, our endpoint measurements revealed that E. coli does not exhibit the sharp decline in cell viability that S. oneidensis displays in the presence of MIL-88A after 24 h. Taken together, this suggests that the morphology of MIL-88A is cytotoxic to biofilm-forming bacteria, such as S. oneidensis , although the exact mechanism for this is unclear.…”

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.…”

Engineered Living Materials: Taxonomies and Emerging Trends

“…In recent years, primary advancements in applied ELM technologies have centered on nonmedical applications for design problems in other industries (e.g., electronics, construction, devices, and computing). Engineers have produced electrically conductive biofilms and advanced electrical biosensors using Curli fibers [45][46][47][48] and bacterial cellulose pellicles [49]. Examples of enabling technologies and proofs of concept also exist in the literature related to engineering living photovoltaics [50], electronics [51], and photonic materials [19].…”