We describe herein microfluidic technology for manipulating and monitoring continuous growth of populations of bacteria. A system consisting of approximately ten input and output channels controls more than 100 microdroplet chemostats and enables the manipulation of chemical factors in each microchemostat independently over time. Herein, we characterize the dynamics of bacterial populations in ...

Chemostats are continuous culture systems in which cells are grown in a tightly controlled, chemically constant environment where culture density is constrained by limiting specific nutrients.(1,2) Data from chemostats are highly reproducible for the measurement of quantitative phenotypes as they provide a constant growth rate and environment at steady state. For these reasons, chemostats have ...

The impact of adaptation on the persistence of a balanced polymorphism was explored using the lactose operon of Escherichia coli as a model system. Competition in chemostats for two substitutable resources, methylgalactoside and lactulose, generates stabilizing frequency-dependent selection when two different naturally isolated lac operons (TD2 and TD10) are used. The fate of this balanced poly...

We studied the effects of protist predation on the composition and morphological structure of a marine bacterioplankton assemblage. A mixed bacterial assemblage (0.6 μm filtered North Sea inoculum) was cultivated with unamended seawater as medium in four 1-stage chemostats. After the establishment of a bacterial community, 2 of the chemostats received a 2 μm filtered seawater inoculum which ena...

HE correlation of spontaneous mutation with active growth in cell culture Thas led in the past to a common tacit assumption that division is required for mutation, an assumption exposed by the expression of mutation rates as some function of division. A ready explanation was provided by the error (copy-error) hypothesis which views mutation as an error in gene duplication, and which predicts th...

Observing organisms that evolve in response to strong selection over very short time scales allows the determination of the molecular mechanisms underlying adaptation. Although dissecting these molecular mechanisms is expensive and time-consuming, general patterns can be detected from repeated experiments, illuminating the biological processes involved in evolutionary adaptation. The bacterioph...

Chemostat models provide the foundation for much current research in bioengineering, ecology, and population biology [8]. In engineering, the chemostat is known as the continuous-stirred tank reactor. It is used to model the dynamics of interacting organisms in waste-water treatment plants, lakes and oceans, and in biomedical contexts. The basic mathematical model of the chemostat is a system o...