摘要
目的 探讨3株大肠杆菌在4种温度下于低营养水体中菌密度随保存时间变化的规律性及其对实际工作的意义。方法 选用大肠杆菌标准株ATCC25922、8099及从人类粪便分离的野生型大肠杆菌,分别配制成一定菌密度的模拟水样,置于恒温水浴箱中,控温在5、15、25、35℃4个水平,以滤膜荧光法定量检测其菌密度的变化。结果 大肠杆菌在低营养水中不繁殖,菌密度随时间的变化在不同温度下均呈负指数函数关系:y=ae-bt;在相同温度条件下,ATCC25922菌密度下降最快,野生株次之,8099株最慢;不同温度下其规律为35℃下降最快,25℃次之,15℃最慢。结论 不同菌株大肠杆菌在低营养水体中的菌密度变化各不相同,与菌株、环境温度以及保存时间关系密切。
ve To explore the regularity of changes of density of three strains of Escherichia coli in un-dernourished water at different 4 levels of temperature. Methods The simulated water samples respectively prepared with standard strains of ATCC 25922, 8099 and wild strain of Escherichia coli seperated from human faeces were in-cubated in thermostat water bath at temperatures of 5℃ , 15℃, 25℃ and 35℃ respectively. The densities of Es-cherichia coli in water samples were determined by filter membrane fluorometry quantitatively. Results No prolif-eration of Escherichia coli was found in undernourished water samples. The densities of Escherichia coli variated with the incubation durations at different temperatures according to negative exponential function:y=ae-bt. The orders of speed of decrease of Escherichia coli density in water samples were ATCC 25922 > wild strain of Escherichia coli > 8099 at the same temperature, and at the different temperatures: 35℃ > 25℃ >15℃ . Conclusion The changes of density of different strains of Escherichia coli in the undernourished water samples closely associated with the strain ' characteristics, environment temperatures and preserving time, showed significantly differences.
出处
《环境与健康杂志》
CAS
CSCD
北大核心
2002年第3期173-174,共2页
Journal of Environment and Health
基金
铁道部科技基金资助项目(J98Z11)
关键词
大肠杆菌
菌密度
温度
低营养水体
Escherichia coli
Bacterial density
Temperature
Undernourished water
