Repurposing E. coli by Engineering Quorum Sensing and Redox Genetic Circuits

Abstract

Because cells have the extraordinary ability to sense and respond to even subtle environmental changes by intricately regulating their gene expression patterns, their behaviors can be intentionally "tuned" by altering the state of their environments in a prescribed or rational manner. Rational control of both external and internal molecular stimuli provides a basis for many biotechnological applications including the expression of foreign protein products. This is done by coordinately controlling product synthesis while retaining the cell in a productive state. Quorum sensing (QS), a molecular signaling modality that mediates cell-cell communication, autonomously facilitates both inter-and intra-species gene regulation. This process can be rewired to enable autonomously actuated, but molecularly programmed, genetic control. Recently, even electrical signals, which have long been used to control the most sophisticated of man-made devices, are now employed to alter cell signaling processes enabling computer programmed behavior, particularly in cells suitably engineered to accommodate electrical signals. By minimally engineering these genetic circuits, new applications have emerged for the repurposing of Escherichia coli, from creating innovative sensor concepts to stimulating the emerging field of electrogenetics.Gene Expression and Control 2 as well as the extracellular microenvironmental state in the vicinity of 'designer' production strains in order to program gene expression and behavior. These techniques incorporate the understanding of cell metabolism and the transcriptome, cell-cell communication (previously reviewed by [2,3]), and biological redox reactions (previously reviewed by [4]). This chapter will mainly focus on recent advances in how actuation of genes is accomplished in Escherichia coli through methods that require only minimal genetic rewiring and the technologies developed on such platforms, for instance those of biosensors and bioelectric devices.

Redox-enabled Electronic Interrogation and Feedback Control of Hierarchical and Networked Biological Systems

“…Here, we show that electronically programming two QS-related functions enables broad utility for manipulating microbial communities. Widespread in nature, QS signaling represents an ideal candidate for dispatching a highly-localized electrochemical cue to other ex situ biological populations with none or minimal genetic rewiring 28,50,51 , and achieving coordination within a natural or synthetic consortium 8,52 .…”

Studies on Biosensors- Recent Developments and Future Perspectives on Biotechnological Applications: An Overview

“…In P. aeruginosa, the Las1-LasR quorum sensing regulatory circuit is fully functional. N-3oxododecanoylhomoserine lactone, an AHL signal, and an AHL synthetase are all encoded by LasRen [24]. During invasion and colonisation, P. aeruginosa uses Nacylhomoserine lactone (AHL) as a command language to coordinate population behaviour (Fig.…”