title: Determining the optimal thymidine concentration for growing Thy- Escherichia coli strains.
abstract: Changes of thymidine concentration in the growth medium affect the chromosome replication time of Thy- strains without at the same time causing a detectable difference in the growth rate (R. H. Pritchard and A. Zaritsky, Nature 226:126-131, 1970). Consequently, the optimal thymidine concentration cannot be determined by ascertaining which concentration produces the highest growth rate. Here we present a method for determining the optimal thymidine concentration of any Thy- Escherichia coli strain. Using this method, we found that the E. coli "wild-type" strain MG1655 has a partial Thy- phenotype.
authors.affiliation: Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, E-06080 Badajoz, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Molina
authors.forename: A
authors.initials: A
authors.lastname: Jiménez-Sánchez
authors.forename: E C
authors.initials: EC
authors.lastname: Guzmán
mesh_terms: D001431:Bacteriological Techniques; D002453:Cell Cycle; D003470:Culture Media; D004261:DNA Replication; D004926:Escherichia coli / Q000254:growth & development*; D013936:Thymidine
chemical_list: D003470:Culture Media; D013936:Thymidine