环境因子及接种量对单增李斯特菌生长的影响

Effect of Environmental Factors and Different Inoculum Size on Growth State of Listeria monocytogenes

为探究不同环境因子及接种量对单增李斯特菌(LM90)生长特性的影响,本试验通过测定LM90在各培养条件下的D600nm值,分析了不同的温度、NaCl浓度、pH,以及温度(0~40℃,梯度为10℃)、NaCl浓度(3%~8%,梯度为1%)、pH(6~9,梯度为1)的交互作用下LM90的生长状况。结果显示,菌株的对数增长期为8~16h,稳定期为16~20h,20h以后进入衰亡期;菌株在NaCl浓度为0.5%~4%时生长良好,其最适生长pH为7.5,最适生长温度为37℃。通过SPSS 20.0软件进行方差分析可知,各因素的交互作用均对LM90有极显著影响(P<0.01)。本研究为进一步探讨温度、NaCl浓度、pH等因素对LM生长的影响及LM抗环境胁迫的作用机制奠定了基础。

In order to explore the growth characteristics of the Listeria monocytogenes（LM90）strain under different environmental factors and inoculum size,the D600 nmvalue of bacteria culture broth were measured,the growth status of LM90 under different NaCl concentration,pH value,temperature and the interactions of NaCl concentration（3% to 8%,1% for per gradient）,pH（6to 9,one for per gradient）,temperature（0to 40℃,10℃for per gradient）had been analyzed.The results showed that the strain was in the logarithmic phase when culturing for 8to 16 h,then entered the stationary phase when culturing for 16 to 20h,and finally went to decline phase when culturing after 20 h.It could grow well when the NaCl concentration was 0.5%to 4%.Its optimum growth pH and temperature were 7.5and 37 ℃,respectively.The interaction effect of each two factor had been analyzed by variance analysis of SPSS software,and it found that the interaction effects was extremely significantly（P0.01）.The study lay a foundation for exploring the effects of environmental factors on LM90 growth and mechanisms of resistance to environmental stresses.