In RE-SENSE we propose a new approach to biosensing: the introduction of innovative computational modelling of gene expression to the “tailoring” and optimisation of synthetic biology pathways for whole-cell biosensor design, advancing the field significantly beyond its current state of the art. We will demonstrate the feasibility of this concept by enhancing the performance of biosensors engineered for the remote detection of buried landmines.
Whole-cell biosensors harbour live, functional cells as their sensing entities, and are therefore the only class of sensors able to detect the biological effects exerted by analysed samples or environments. Standard genetic engineering of such sensor strains is based on a molecular fusion, inside a living bacterial cell, of a sensing element (usually a gene promoter known to be induced by the target compound(s), and a reporting element – gene(s) the product(s) of which can be monitored quantitatively. However, accurate engineering of a live cell is extremely challenging, and current approaches do not provide efficient solutions.
RE-SENSE will dramatically advance this current simplistic molecular engineering theme by employing innovative computational models of gene expression that we have recently proven to be highly successful in other systems. These include: (a) computational design of all components of relevant transcripts (promoters, UTRs, coding regions); (b) design based on computational biophysical models related to all gene expression aspects such as transcription, translation, RNA degradation, etc.; (c) unsupervised models for gene expression engineering; (d) state of the art synthetic biology approaches for efficient evaluations of potential solutions; (e) large-scale measurements of gene expression variables related to the systems and the endogamous genes.
The detection of buried landmines is a humanitarian issue of global proportions that is in acute need of a practical solution. Current mine detection technologies require presence in the immediate area of the mines, with obvious risks to personnel; no solution currently exists for remote mapping of minefields. We have recently demonstrated a successful standoff detection of buried landmines, employing bioluminescent bacterial whole-cell sensors dispersed over the test area. These original sensor strains, molecularly engineered for explosives’ vapours detection, will serve as the starting material for the redesign process, which will address two complementary objectives: (a) manipulating the sensing element, thus providing a potential enhancement in detection sensitivity (i.e., lowering of the detection threshold) that may reach several orders of magnitude; (b) significantly improving the reporting element, the bacterial bioluminescence (lux) genes. The latter achievement is expected to have consequences far beyond the present project, since bioluminescence is a very common reporter function, universally employed in numerous applications.