Study the effect of cultural condition on growth state of Listeria monocytogenes

This study was based on Listeria monocytogenes of 99.97% purity,and determined the growth curve of strain before changing medium conditions,and then culture conditions had been adjusted.By measuring the OD600 value of bacteria liquid under different cultural condition,the growth status of Listeria monocytogenes under different NaCl concentration,pH value,temperature and their interactions under NaCl concentration 3% ～8% ( one for per gradient) ,pH 6～9( one for per gradient) ,temperature 0～40℃( 10℃ for per gradient) had been analyzed. The results showed that the logarithmic phase of this strain was 8 ～14h,the stationary phase was 14 ～18h,and it entered into decline phase after 18h. It could grow well in range of 0.5% ～ 3.5% concentration of NaCl and its optimum growth pH value was 7.5,and its optimum growth temperature was 37℃. The interaction effect of each factor had been analyzed by means of SPSS software,and variance analyses had been carried out,and results showed that the p 0.01,and that means interaction effects were quite notable.