A sensing array of radically coupled genetic ‘biopixels’

• Published in: Nature (London) Vol. 481; no. 7379; pp. 39 - 44
• Main Authors: Prindle, Arthur, Samayoa, Phillip, Razinkov, Ivan, Danino, Tal, Tsimring, Lev S., Hasty, Jeff
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05-01-2012; Nature Publishing Group
• Subjects: 631/553/2695; 631/553/338/552; 631/61/350/59; 631/61/350/877; Ampicillin - pharmacology; Anti-Bacterial Agents; Arsenic; Arsenic - analysis; Bacterial Proteins - metabolism; Binding sites; Biological and medical sciences; Biological Clocks - drug effects; Biosensing Techniques; Biosensors; Catalase - metabolism; Design; E coli; Escherichia coli - drug effects; Escherichia coli - enzymology; Escherichia coli - genetics; Escherichia coli - physiology; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Bacterial; Heavy metals; Humanities and Social Sciences; Hydrogen Peroxide - metabolism; Kanamycin - pharmacology; Liquid Crystals; Molecular and cellular biology; multidisciplinary; NADH Dehydrogenase - metabolism; Oxidation-Reduction; Plasmids; Quorum Sensing; Science; Science (multidisciplinary); Superoxide Dismutase - metabolism; Synthetic Biology; Thiourea - pharmacology; United States; Communication process; Prokaryote; Bacteria; Genetics; Quorum sensing; Synthetic biology; Microorganism
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature10722

Although there has been considerable progress in the development of engineering principles for synthetic biology, a substantial challenge is the construction of robust circuits in a noisy cellular environment. Such an environment leads to considerable intercellular variability in circuit behaviour, which can hinder functionality at the colony level. Here we engineer the synchronization of thousands of oscillating colony ‘biopixels’ over centimetre-length scales through the use of synergistic intercellular coupling involving quorum sensing within a colony and gas-phase redox signalling between colonies. We use this platform to construct a liquid crystal display (LCD)-like macroscopic clock that can be used to sense arsenic via modulation of the oscillatory period. Given the repertoire of sensing capabilities of bacteria such as
Escherichia coli
, the ability to coordinate their behaviour over large length scales sets the stage for the construction of low cost genetic biosensors that are capable of detecting heavy metals and pathogens in the field.
Thousands of quorum-sensing
Escherichia coli
colonies are synchronized over centimetres using redox signalling to create ‘biopixels’ that can sense trace amounts of arsenic in water.
Sensing with biopixel colonies
The first synthetic biological oscillators, networks of transcriptional regulators designed to perform a single function, were developed just over a decade ago. Recently it became possible to synchronize a colony of such oscillators coupled through bacterial quorum sensing, but this was limited to short-range synchrony. Now, by combining two synergistic modes of communication — generation of hydrogen peroxide vapour and redox signalling — Jeff Hasty and colleagues have synchronized extremely large populations (around 50 million cells) of
Escherichia coli
bacteria distributed in quorum-sensing colonies, or biopixels, spread across centimetres. This array was used to build an LCD-like macroscopic clock capable of sensing the presence of arsenic through modulation of the oscillatory period. With further development, biopixel colonies of this type might form the basis of low-cost genetic biosensors capable of detecting heavy metals and pathogens.