Effect of growth phase on the subsequent growth kinetics of psychrotrophic bacteria of raw milk origin

Psychrotrophs isolated at days 1, 3 and 5 from refrigerated raw milk were monitored for growth kinetics using conductance when they had been inoculated during their lag, log and stationary growth phases. The results indicated that there was a more rapid change in the microflora during the initial stages of storage when the lag phases of the 1, 3 and 5 day isolates were analysed. There was also evidence of the ‘suicide response’. In addition, the fact that the stationary phase cells showed the greatest exponential growth rate may be a contributory factor to their selective advantage.