Na tri izolata vrste Pseudomonas fluorescens izolirana iz pasteriziranog mlijeka proučavali smo utjecaj veličine populacije na kinetiku odumiranja za trajanje pasterizacije mlijeka (63 °C/30 min). Bez obzira na veličinu populacije i pojedine izolate, do najveće redukcije broja stanica došlo je u vrijeme dogrijavanja uzroka do 63 °C (4 min.). Ako je početna populacija bila <10^4 BK/ml ustanovili smo sto postotnu letalnost. Nakon 48 sati skladištenja (7 °C) i u tim uzorcima pasteriziranog mlijeka zapazili smo prisustvo živih stanica.The influence of initial population size on destruction kinetics during milk pasteurization (63 °C/30 min) was studied relative to three Pseudomonas fluorescens isolates from pasteurized milk. The greatest reduction of viable cells was observed during first stage of milk pasteurization to reaching final temperature (63 °C/4 min) for all isolates and every starting population size. When inital population size attained <10^4 CFU/ml lethality determined immediately after pasteurization was 100%. Despite this fact viable cells were observed in all samples of pasteurized milk stored 48 hours at 7 °C