延边大学农学学报

为了对大肠杆菌的不同计数方法进行比较研究,并探究OD₆₀₀值、浊度与大肠杆菌活菌数之间的关系。试验采用大肠杆菌作为试验菌株,将细菌配制成菌悬液,用分光光度计、浊度计测量其OD₆₀₀值及浊度,并采用平板计数法、显微计数法检测细菌数量,进行比较分析。结果表明:大肠杆菌2种计数方法的计数结果为显微计数法>平板计数法,且2种计数方法之间存在各自的特点;同时,大肠杆菌菌液OD₆₀₀值和浊度与活菌数呈线性关系,其回归方程分别为y=27.067 x-4.025和y=0.156 x-0.169,均呈良好的相关性,可根据回归方程,测量OD₆₀₀值或浊度直接推算出细菌的活菌数,其方法简单方便,为大肠杆菌计数问题提供理论依据。

This experiment aimed to compare the different counting methods of Escherichia coli and explore the relationship among OD₆₀₀ value, turbidity and viable count, Escherichia coli was used as the test strain,the bacterial suspension was prepared. OD₆₀₀ value and turbidity were measured by spectrophotometer and turbidimeter. The number of bacteria was detected and analyzed by plate counting method and microscopic counting method. The results showed the microscopic counting was better than plate counting of E. coli, and there were respective characteristics between the two counting methods. At the same time, the OD₆₀₀ value of E. coli liquid and turbidity had linear relationship with the number of live bacteria, and the regression equations were y=27.067 x-4.025, y=0.156 x-0.169, respectively, which showed good correlation. According to the regression equation, OD₆₀₀ could be measured. The method of direct calculating the number of live bacteria by value or turbidity is simple and convenient, which provides a theoretical basis for the counting of E.coli.