Methodology for Enumerating Viable Bacteria Based on Consecutive Observation of Microbial Growth

Abstract

As an improved methodology for rapidly enumerating viable bacteria, microbial colonies in agar media are observed in the microscopic fashion at regular rate from the initial stage of culturing while media plate is being incubated. At each sampling time, in order to observe colonies in various depths without focusing on any of them, an agar plate is irradiated by a point light source to project the clear shadow of colonies onto the CCD image sensor. The projected image is processed with a computer to detect the colonies automatically. As the result of the experiment with E. coli, the number of colonies had reached to the plateau after six hours of incubation and the enumeration process was completed.