Estimation of the degree of synchrony in microbial populations

The distributions of cell size, cellular division time, and stage of nuclear division were studied in synchronized cultures of C. pyrenoidosa in an attempt to evaluate the effectiveness of the synchronization process. Cell size and stage of nuclear division were not found to be distributed in a manner which would allow their use in a critical evaluation of synchrony in C. pyrenoidosa. The distribution of cellular division time as derived from cell count data was found to possess three measurable parameters (standard deviation, coefficient of variation, and “range coefficient”) which were correlated with the degree of synchrony and were useful in its evaluation. Of the three parameters studied, only the coefficient of variation of division time was found suitable for comparing the degrees of synchrony in cultures which exhibited different mean division times. The algal system studied was found to have a typical peak degree of synchrony characterized by a standard deviation of cellular division time of 39 min with a coefficient of variation of 6.06 per cent and a “range coefficient” of 0.77.