The new role of the microchemostat in the bioengineering revolution.

Since the inception of synthetic biology as a discipline, bioengineers have used the electronic circuit paradigm to analyze, model, simulate and interpret the behavior of genetic circuits. In this paper, we elaborate upon the effect of evolution as an overriding attribute of the biological systems, which makes genetic circuits inherently fickle compared to their electronic counterparts. Shrinking the volume of programmed microbial population reduces the effects of evolution. This concept was demonstrated by characterizing the dynamics of Escherichia coli cells carrying a synthetic "population control" circuit, which regulates cell density through a feedback mechanism based on quorum sensing. The microchemostat prolonged the lifetime of the programmed circuit by at least an order of magnitude compared macro-scale characterization schemes.