Bacterial growth rate serves as a fundamental parameter in microbiology. Typically, this aspect is assessed by measuring the optical density at different time intervals. In this way, the doubling time of the entire population can be measured. However, population-level analyses may miss important heterogeneity that is present at the single-cell level. For this reason, if we want to understand in more detail the phenotypic heterogeneities or the processes themselves at the level of individual colonies, it is desirable to monitor the growth of individual cells. For this purpose, we tested the functionality of the ScanLag method for monitoring the growth of bacterial colonies and explored the possibilities of its use. To execute this investigation, we carried out experiments that would cover different growth conditions to gain insight into the growth kinetics of individual bacterial colonies, as well as to test the limitations of the ScanLag program itself. The method is based on the automatic capture of images of bacterial colonies on agarose plates using a commercial scanner. For the analysis, we used computer programs developed using MatLab. The analysis was automatic and fast, and the ScanLag programs were free. With automatic image analysis, we could monitor the expansion of individual colonies, and thus determine the speed of growth.
|
