Fig. 5. Disruption of the S-1-P lyase gene affects viability of cells in stationary phase. (A) Wild-type and S-1-P lyase-null cells were inoculated into HL-5 medium at 2x10⁵ cells per ml for axenic growth and the cell numbers were followed. Triplicate cultures of each were examined. Each point is the mean of duplicate counts. (B) Wild-type and S-1-P lyase cells were harvested at a density of 3x10⁶ cells per ml and deposited at a standard density of 8x10⁶ cells/cm² for development. At the indicated times, duplicate filters were harvested into 20 ml of SS buffer containing 10 mM EDTA and disaggregated by vortexing until there was a uniform suspension of single cells. The cells from each filter were counted in duplicate and the bars in the figure indicate the standard deviation.