biostudies-literatureRolfe MDBiotechnology and Biological Sciences Research Council686-701https://www.ebi.ac.uk/biostudies/studies/S-EPMC3264077biostudies-literatureUnknown194(3)Lag phase represents the earliest and most poorly understood stage of the bacterial growth cycle. We developed a reproducible experimental system and conducted functional genomic and physiological analyses of a 2-h lag phase in Salmonella enterica serovar Typhimurium. Adaptation began within 4 min of inoculation into fresh LB medium with the transient expression of genes involved in phosphate uptake. The main lag-phase transcriptional program initiated at 20 min with the upregulation of 945 genes encoding processes such as transcription, translation, iron-sulfur protein assembly, nucleotide metabolism, LPS biosynthesis, and aerobic respiration. ChIP-chip revealed that RNA polymerase was not "poised" upstream of the bacterial genes that are rapidly induced at the beginning of lag phase, sugJournal of bacteriologyLag phase is a distinct growth phase that prepares bacteria for exponential growth and involves transient metal accumulation.PMC3264077BBS/S/M/2006/13059BBS/E/F/00044406BBS/S/N/2003/10520BBS/E/F/00044401Pin CRolfe MDThompson ABetts RPRice CJBaranyi JAlston MCameron ADHinton JCLucchini SStringer MFPeck MWfalseLag phase is a distinct growth phase that prepares bacteria for exponential growth and involves transient metal accumulation.Lag phase represents the earliest and most poorly understood stage of the bacterial growth cycle. We developed a reproducible experimental system and conducted functional genomic and physiological analyses of a 2-h lag phase in Salmonella enterica serovar Typhimurium. Adaptation began within 4 min of inoculation into fresh LB medium with the transient expression of genes involved in phosphate uptake. The main lag-phase transcriptional program initiated at 20 min with the upregulation of 945 genes encoding processes such as transcription, translation, iron-sulfur protein assembly, nucleotide metabolism, LPS biosynthesis, and aerobic respiration. ChIP-chip revealed that RNA polymerase was not "poised" upstream of the bacterial genes that are rapidly induced at the beginning of lag phase, sug2012-01-01T00:00:00Z2012 Feb2026-05-01T01:07:45.599Z2026-04-07T16:28:22.884ZS-EPMC32640772213950510.1128/jb.06112-1110.1128/JB.06112-11