Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher.
Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?
Some links on this page may take you to non-federal websites. Their policies may differ from this site.
-
more » « less
Abstract Electronic information can be transmitted to cells directly from microelectronics via electrode-activated redox mediators. These transmissions are decoded by redox-responsive promoters which enable user-specified control over biological function. Here, we build on this redox communication modality by establishing an electronic eCRISPR conduit of information exchange. This system acts as a biological signal processor, amplifying signal reception and filtering biological noise. We electronically amplify bacterial quorum sensing (QS) signaling by activating LasI, the autoinducer-1 synthase. Similarly, we filter out unintended noise by inhibiting the native SoxRS-mediated oxidative stress response regulon. We then construct an eCRISPR based redox conduit in both
E. coli andSalmonella enterica . Finally, we display eCRISPR based information processing that allows transmission of spatiotemporal redox commands which are then decoded by gelatin-encapsulatedE. coli . We anticipate that redox communication channels will enable biohybrid microelectronic devices that could transform our abilities to electronically interpret and control biological function. -
more » « less
In addition to engineering new pathways for synthesis, synthetic biologists rewire cells to carry out “programmable” functions, an example being the creation of wound‐healing probiotics. Engineering regulatory circuits and synthetic machinery, however, can be deleterious to cell function, particularly if the “metabolic burden” is significant. Here, a synthetic regulatory circuit previously constructed to direct
Escherichia coli Biotechnol. Prog ., 35: e2778, 2019. -
more » « less
Abstract Probiotics, whether taken as capsules or consumed in foods, have been regarded as safe for human use by regulatory agencies. Being living cells, they serve as “tunable” factories for the synthesis of a vast array of beneficial molecules. The idea of reprogramming probiotics to act as controllable factories, producing potential therapeutic molecules under user‐specified conditions, represents a new and powerful concept in drug synthesis and delivery. Probiotics that serve as drug delivery vehicles pose several challenges, one being targeting (as seen with nanoparticle approaches). Here, we employ synthetic biology to control swimming directionality in a process referred to as “pseudotaxis.”
Escherichia coli , absent the motility regulatorcheZ , swim sporadically, missing the traditional “run” in the run:tumble swimming paradigm. Upon introduction ofcheZ in trans and its signal‐generated upregulation, engineered bacteria can be “programmed” to swim toward the source of the chemical cue. Here, engineered cells that encounter sufficient levels of the small signal molecule pyocyanin, produce an engineered CheZ and swim with programmed directionality. By incorporating a degradation tag at the C‐terminus of CheZ, the cells stop running when they exit spaces containing pyocyanin. That is, the engineered CheZ modified with a C‐terminal extension derived from the putative DNA‐binding transcriptional regulator YbaQ (RREERAAKKVA) is consumed by the ClpXP protease machine at a rate sufficient to “brake” the cells when pyocyanin levels are too low. Through this process, we demonstrate that over time, these engineeredE. coli accumulate in pyocyanin‐rich locales. We suggest that such approaches may find utility in engineering probiotics so that their beneficial functions can be focused in areas of principal benefit.
