[Determination of bacteria count by enumeration of microcolonies with an electronic counter apparatus (author's transl)].

In this paper a method is described to determine the bacteria count of samples by enumerating the microcolonies with the aid of a "Coulter Counter" automatic apparatus. Samples of bacterial cultures were incubated in a suitable medium at 32 degrees C for 12 h, then passed through a Coulter Counter aperture of 200 mu diameter to count the microcolonies. Microcolonies from cultures grown in similar conditions were also enumerated by the classical plate method. Comparison showed a good correction between the two sets of results after logarithmic transformation. Some advantages and limitations of this automatic technique are discussed, in view of its routine employment in food analysis.