Engineering multi-strain population control systems in bacterial consortia

Traditionally, synthetic biology has relied upon monocultures, single strain microbe populations to conduct all stages of a production process. Each stage of the pathway is executed by a different gene product. The expression of each gene exerts a metabolic load on the cell. Additionally, cross-talk between genes can cause unanticipated behaviour. Both these features limit the complexity of systems we can build when operating in a monoculture.
By splitting distinct components of a pathway across several organisms, we reduce metabolic burden on each individual, and reduce cross-talk between genes. This would allow for the construction of more complex, and potentially more efficient systems. Communities may also exhibit emergent robustness to environmental conditions. Being able to maintain normal functionality in changing conditions adds flexibility to the of a bioprocess, with the potential for more cost-effective working conditions.
In order to establish a microbial consortium, we need engineer communication and feedback mechanisms between the consortium members. Our work will build upon a synthetic predator-prey system developed by Balagadde et. al 2008 that uses a quorum sensing components coupled with the ccdA/ccdB toxin-antitoxin system. We plan to extend this platform to construct systems involving multiple predator and prey species.