大肠杆菌菌液浓度与吸光度之间相关性研究

Study on the relations between Escherichia coli suspension concentration and absorbance

为了建立通过测定吸光度快速检测大肠杆菌菌液浓度的方法,将大肠杆菌接种于牛肉膏蛋白胨培养基中,培养至0h、2h、3h、3.5h、4h、4.5h分别取样,用平板菌落计数法测定每个样品中的活菌数,同时测定每一样品在500nm波长处的吸光度值,进而研究二者之间的相关性,建立大肠杆菌菌液浓度与吸光度之间的标准曲线,并对分光光度法测定大肠杆菌菌液浓度的准确性进行验证。结果表明:大肠杆菌菌液浓度与吸光度之间呈线性相关。

The present study was aimed to establish a method for quickly calculating Escherichia coli suspension concentration by spectrophotometry. Escherichia coli was inoculated in the beef extract peptone medium. The bacterium samples were collected on 0, 2.0、 3.0、 3.5、 4.0、 4.5 hour during the culture,which were used to calculate the number of viable bacteria suspension by plate count method. Meanwhile the corresponding absorbance( A500nm) was determined. Then the standard curve between the Escherichia coli suspension concentration and absorbance was established. A sample was used to compare and verify the plate count method and spectrophotometer method. The result suggested that Escherichia coli counts and absorbency showed linear correlation. The Escherichia coli suspension concentration can be calculated quickly by measuring the absorbency of the Escherichia coli suspension concentration.