title: The cytostat: A new way to study cell physiology in a precisely defined environment.
abstract: In a cytostat, a continuous culture is monitored and controlled by an automated flow cytometer system, based on the determination of the cell concentration and the single cell property distribution of the growing cell population. The growing culture can be maintained at steady state even at such low cell concentrations that the bioreactor medium composition is negligibly changed by the few cells. Therefore, the cell environment is precisely defined by the feed composition since products of cell growth are not present in significant amounts. Effects on cell growth of nutrients, of toxic compounds such as drugs, or of products made by the cells, if added to the feed medium, can be readily isolated. Using the cytostat, it is shown here that ethanol assumes the triggering function for the increase in cell size in Saccharomyces cerevisiae normally only seen at critical growth rates above critical cell densities. This suggests that ethanol assumes a quorum sensing function on cell growth when a critical cell density is reached.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, 151 Amundson Hall, 421 Washington Avenue S.E., Minneapolis, MN 55455-0312, USA.
authors.forename: James
authors.initials: J
authors.lastname: Kacmar
authors.forename: Alan
authors.initials: A
authors.lastname: Gilbert
authors.forename: Janelle
authors.initials: J
authors.lastname: Cockrell
authors.forename: Friedrich
authors.initials: F
authors.lastname: Srienc
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000295:instrumentation* / Q000379:methods; D049108:Cell Enlargement; D002468:Cell Physiological Phenomena; D049109:Cell Proliferation; D004780:Environment, Controlled; D004867:Equipment Design; D019544:Equipment Failure Analysis; D000431:Ethanol / Q000378:metabolism; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000502:physiology*
chemical_list: D000431:Ethanol