Fig 5.
A decrease in culture turbidity and the release of a cytoplasmic enzyme and intracellular pigments indicate modulation of cell lysis by phosphate. (A) Kinetics of changes in culture turbidity of the overproducer DE442 and WT SB1003 strains grown in the presence of several concentrations of phosphate; (B) kinetics of change in the culture turbidity of overproducer DE442 after addition of phosphate; (C) extracellular fraction of cytoplasmic enzyme malate dehydrogenase relative to the total (extracellular plus intracellular) specific activity in DE442 cultures grown in the presence of different concentrations of phosphate; (D) absorption spectra of cell-free culture supernatants of strains DE442, DE442 ΔcckA, DE442 ΔcckA complemented in trans with pRCckA, and DE555 in the region from 750 to 950 nm, showing transmembrane LH2 complex peaks at 802 and 855 nm. Samples were blanked against sterile RCVm medium. All samples were from cultures grown in RCVm containing 0.5 mM KPO4, unless otherwise indicated. Growth curves (A and B) show the average of two biological samples. Error bars represent the standard deviations of three biological replicates.