title: Determination of deoxyribonucleic acid replication time in exponentially growing Escherichia coli B/r.
abstract: The time necessary to replicate the chromosome (C period) was measured in Escherichia coli B/r (ATCC 12407) and a low-thymine-requiring derivative of that strain. In the Thy- strain, C was measured as a function of growth rate and exogenous thymine concentration either from step-up or chloramphenicol experiments. In the Thy+ parental strain, C was measured only as a function of the growth rate and only by the chloramphenicol method. The C period was found to decrease with growth rate and, in the Thy- strain, the C period also decreased with increasing thymine concentration. It approached a value of approximately 37 min at high growth rates.
mesh_terms: D002701:Chloramphenicol / Q000494:pharmacology; D002876:Chromosomes, Bacterial / Q000187:drug effects / Q000378:metabolism; D003470:Culture Media; D004261:DNA Replication; D004269:DNA, Bacterial / Q000096:biosynthesis* / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D005787:Gene Frequency; D013941:Thymine / Q000494:pharmacology; D013997:Time Factors
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D002701:Chloramphenicol; D013941:Thymine