Ga. Mitchell et al., THE EFFECT OF TRANSIENT TEMPERATURES ON THE GROWTH OF SALMONELLA-TYPHIMURIUM LT2 .2. EXCURSIONS OUTSIDE THE GROWTH REGION, Journal of Applied Bacteriology, 79(2), 1995, pp. 128-134
The effect of fluctuating temperatures on microbial growth is importan
t in the passage of foods from production to consumption. Suspensions
of Salmonella typhimurium have been subjected to sinusoidally time-var
ying temperatures of periods from 60 to 240 min between 4 degrees and
22 degrees C, that is within and below the growth temperature range, T
he suspensions were prepared with two concentrations of sodium chlorid
e and adjusted to two different values of pH, The change in the number
s of viable bacteria was measured with time and the experimental growt
h curves and average generation times compared with predictions based
on isothermal growth data. Generally, the experimental average generat
ion times exceeded the predictions by not more than 10%, In enumeratin
g viable bacteria in the suspensions containing 3.5% (w/v) sodium chlo
ride it was necessary to use sodium chloride in the diluent and recove
ry medium in order to recover the bacteria quantitatively.