Experimental evolution is one approach used to address a broad range of questions related to evolution and adaptation to strong selection pressures. Experimental evolution of diverse microbial and viral systems has routinely been used to study new traits and behaviors and also to dissect mechanisms of rapid evolution. This protocol describes the practical aspects of experimental evolution with ...

Perfusion culture optimization in multiple noninstrumented small-scale flasks allows reduced expense and time associated with process development. These cultures normally use a different process mode because at small scales it is not practical to retain the cells for medium perfusion. In this work, the kinetics of growth, nutrient consumption, metabolite, and product formation were compared in ...

The chemostat plays a well-established role as a model open system in ecology the comprehensive monograph see [HSm95]. Basically, the chemostat consists of a nutrient input pumped at a constant rate into a well-mixed culture vessel. Volume is kept constant by pumping the mixed contents out at the same rate. We assume all nutrients needed for growth, except one, to be present in abundance. In ad...

In acetate-limited chemostat cultures started with single-colony cultures of Thiobacillus versutus, a mutant appeared after approximately 85 volume changes. The inhomogeneity of the culture was detected by the development of two different types of colonies on agar plates. When a pure culture of the mutant was grown in a chemostat, parent colonies appeared after almost the same period of time. E...

Two different growth media, namely complex and defined media, were used to examine establishment of steady-state conditions in phosphate-limited culture system of Saccharomyces cerevisiae CEN.PK113-5D strain. Using the defined growth medium, it was possible to obtain steady state condition in the continuous culture. The effect of phosphate concentration on the growth of S. cerevisiae in pho...

A two-stage chemostat was used to study removal of cadmium by microorganisms in continuous culture. The medium was contaminated with 0.8 mg of Cd per liter. At 20 degrees C, most of the microbial biomass formed aggregates which settled in the second stage of the chemostat. Effluent was free of bacteria. Up to 80% of the metal contained in the inlet flux was removed by the biomass, with 20% rema...

Intrinsic antimicrobial resistance of Escherichia coli is elicited by the gene products of the multidrug efflux acrAB-tolC operon. In this paper, we have shown that acrAB is regulated as a function of the growth rate of E. coli during growth in batch and chemostat culture. In chemostat culture, expression of acrAB is inversely related to growth rate irrespective of the limiting nutrient. The le...