Quantifying the combined effect of salt and temperature on the growth of Listeria strains isolated from salmon and salmon processing environments

Abstract

The effects of temperature and salt concentration on the growth of relevant strains of L. monocytogenes and Listeria innocua, were quantified based on growth in a liquid broth medium, monitored by measuring turbidity. Absorbance curves were used to estimate maximum growth rate and lag time. The growth rates increase with increasing temperatures. The levels were quite similar for both species, although L. monocytogenes showed higher growth rate than L. innocua at 4°C. Lag time was more affected both by temperature and salt concentration, and these effects were most prominent for L. innocua.