Antimicrobial effect of carvacrol on Escherichia coli K12 growth at different temperatures

摘要

A study was carried out to evaluate the antimicrobial activity of carvacrol on Escherichia coli K12 (CECT 433) at different incubation temperatures (30 and 37 °C). Regardless of the temperature, both the maximum specific growth rate (μ_(max)) and the lag phase (λ) showed to be dependent on the carvacrol concentration but in different ways. While λ was directly proportional to the antimicrobial concentration, μ_(max) showed to be inversely proportional to it, being 0.14 μl ml~(-1) a lethal concentration, and existing a log-linear relationship between that parameter and the tested concentrations (R ≥ 0.900). Comparing the results for both temperatures for each concentration, no significant differences were detected in μ_(max) but λ is always longer at 30 °C than at 37 °C (P_(value) ≤ 0.05). These results indicate that carvacrol is active against E. coli K12 growth, so it could be used to extend the shelf life and improve the safety margins of minimally processed foods.