RELATIONSHIP BETWEEN COLONIAL SURFACE AND DENSITY ON AGAR PLATE

The size of a colony on an agar plate is influenced by the number of c olonies (N) on this plate. When N is small, colonies reach a larger si ze. The relationship between colonial surface and density of bacteria on agar plate was studied for nine bacterial and two yeast strains. A mathematical model describing the relationship between the logarithm b ase 10 of the number of colonies on the agar plate and the average col onial diameter was built. This model is shown to be adapted to most of the strains studied and could be a tool for media quality control.