The Origin of the Time Scale: A Crucial Issue for Predictive Microbiology

The collective behavior of microbial cells in a batch culture is the result interactions among individuals and effects surrounding medium, which changes during growth progress. A semi empirical model skips biological physiological peculiarities microorganisms focuses on observed sigmoid shape curve that common feature cultures pro- eukaryotic microorganisms. replaces trend with an ideal undergoes unperturbed duplication process. It leads one to recognize that: origin time scale for microbes, , differs from observer, t; absolute reference state any log (N) = 0 (no matter base) 0; cell occurs after active latency gap, 0, decreases increasing inoculum population, log2(N0) temperature; substantially lag phase, considered by most authors; use reduced variables allows gathering different curves single master plot; applies undergo change environmental conditions predicts width intermediate gap just change; expression decay population definition parameter suitable rank bactericidal drugs. justifies demand more restricted safety limits loads.