Towards light-mediated sensing of bacterial comfort

• DOI: 10.1111/lam.12255
• Publication Date: 2014-05-01T10:51:13Z
• Authors: G. Zafrilla; A. Iglesias; M. Marín; L. Torralba; P. Dorado-Morales; J.L. Racero; J.J. Alcaina; L.J. Morales; L. Martínez; M. Collantes; L. Gómez; C. Vilanova; M. Porcar
• Keywords: Transcriptional Activation; 0303 health sciences; Nitrogen; Green Fluorescent Proteins; Gene Expression Regulation, Bacterial; 3. Good health; Oxygen; 03 medical and health sciences; Glucose; Genes, Bacterial; Genes, Reporter; Escherichia coli; Gene-Environment Interaction; Synthetic Biology; Promoter Regions, Genetic

Abstract Bacterial comfort is central to biotechnological applications. Here, we report the characterization of different sensoring systems, the first step within a broader synthetic biology-inspired light-mediated strategy to determine Escherichia coli perception of environmental factors critical to bacterial performance. We did so by directly ‘asking’ bacterial cultures with light-encoded questions corresponding to the excitation wavelength of fluorescent proteins placed under the control of environment-sensitive promoters. We built four genetic constructions with fluorescent proteins responding to glucose, temperature, oxygen and nitrogen; and a fifth construction allowing UV-induced expression of heterologous genes. Our engineered strains proved able to give feedback in response to key environmental factors and to express heterologous proteins upon light induction. This light-based dialoguing strategy reported here is the first effort towards developing a human–bacteria interphase with both fundamental and applied implications.

Significance and Impact of the Study The results we present here are at the core of a larger synthetic biology research effort aiming at establishing a dialogue with bacteria. The framework is to convert the human voice into electric pulses, these into light pulses exciting bacterial fluorescent proteins, and convert light-emission back into electric pulses, which will be finally transformed into synthetic voice messages. We report here the first results of the project, in the form of light-based determination of key parameters for bacterial comfort. The ultimate goal of this strategy is to combine different engineered populations to have a combined feedback from the pool.