Y BERSET¹, D MERULLA², A JOUBLIN², V HATZIMANIKATIS¹, J R VAN DER MEER<sup>2

1</sup>Laboratory of Computational Systems Biotechnology, EPF Lausanne (CH); , ²Department of Fundamental Microbiology, University of Lausanne (CH);

Bioreporters are living cells that have been genetically engineered to reveal the presence of a specific chemical compound. Because they are cheap to produce and can potentially be integrated in microfluidics devices,
bioreporters gathered interest as an alternative to chemical analysis of toxic compounds. In order to improve the reliability of arsenic bioreporters, we developed a detailed mechanistic model describing the gene regulatory networks – feedback or uncoupled – involved in bioreporter strains (1). The model includes the binding steps between the regulatory protein ArsR, its specific and non-specific DNA sites and arsenic, as well as the transcription, translation and maturation of the reporter gene (GFP).
We used a part of the experimental data to calibrate the model, i.e. to find sets of model parameters that best fit the data. The parameter search was performed by a population based method and concluded by a gradient method. With the obtained parameters, we tested the ability of the model to simulate the remaining experimental data consisting of allelic variations and deletions.

1. Merulla D, Hatzimanikatis V, van der Meer JR. Tunable reporter signal production in feedback-uncoupled arsenic bioreporters: Uncoupled ArsR genetic circuits. Microbial Biotechnology. 2013 Sep;6(5):503–14.