To genetically reprogram the chemotactic behaviour of E. coli, through the use of synthetic riboswitches. This will enable bacteria to search a defined area for a particular ligand and return to a set location (the starting point), where they can report on their findings. As a proof of principle, we want to test the ability of the reprogrammed cells to locate atrazine/theophylline on a petri-dish, and return to the initial point of departure for reporting. To do this we have three constructs that will make the bacteria toggle between two states of chemotactic responsiveness to different substances.

The CSIR Wits South Africa team consists of five enthusiastic undergraduate students each having their own area of expertise. Four of the members are studying science and one is studying engineering at the University of the Witwatersrand. The biologists are from the schools of Molecular and Cell Biology and Molecular Medicine and Hematology. The team’s engineering students is studying information engineering. This team is a dynamic one where each team member has something unique to offer to the competition.

The team has submitted a number of parts to the registry, including our final genetic machine. We have submitted and characterized two theophylline riboswitches and one atrazine riboswitch. Our flip recombinase toggle switch and its corresponding lox66-promoter-lox 71 construct have also been submitted.

A thorough understanding of bacterial chemotaxis and theophylline and atrazine riboswitches is essential in predicting the behaviour of our machine. The team has created a simulation tools which enables a visual representation of our machine at work!