Rice
From 2007.igem.org
Welcome to the home of Rice University iGEM 2007 Team.
Due to widespread usage of antibiotics, bacteria are developing multiple resistances to overcome the selective pressure put on them by our many “magic bullets.” In bacterial hotspots such as hospitals, these resistances are growing at an alarming and life-threatening rate. Some conventional strategies have been developed to counter this problem including use of large amounts of antibiotics, development of new antibiotics, and utilization of mutually antagonistic antibiotics. These methods tend to be expensive, harmful to the patient, and require a long time to implement. None of these methods remove the selective pressure to develop multiple antibiotic resistances. By conferring selective advantage on bacterial population, we intend to artificially create changes in evolutionary fitness landscape such that bacteria harboring antibiotic resistance are competed out.
Bacteria have evolved diverse genetic systems to sense their environment as well as respond to their surroundings in an adaptive manner. Of recent intense interest is the discovery that bacteria use pheromones that allow them to sense their own population density, a system known as quorum sensing. Another widely studied system is that of chemotaxis, in which a bacterium is able to sense and adaptively swim towards or away from a chemical agent in the environment. The Rice University iGEM team is attempting to merge these two existing natural systems (quorum sensing and chemotaxis) to produce a novel bacterial phenotype (quorumtaxis) in which the engineered cell will be able to detect and swim towards the quorum pheromone of another ‘target’ cell. This project will demonstrate the ability to produce unique complex behavior in bacteria through the modular integration of existing circuits. In addition, precise control over bacterial movement will greatly increase the complexity of systems synthetic biologists could create. The keystone of the project is the design of a novel chimeric receptor which can sense the target pheromone and then signal flagellar rotation within the cell. This project necessitates a highly interdisciplinary approach: the conceptual design and part construction requires backgrounds in biochemistry and cell biology, protein engineering elements requires experience in biomolecular engineering methods, and computational mathematics will be used to model the quorumtaxis phenotype.
