FIG. 2.
Analysis of pigments in WT and mutants of Synechocystis strain PCC 6803. (A) Chl accumulation in Synechocystis strains during photoautotrophic growth. Data shown are from three experiments; the error bars indicate the standard deviation. (B) Quantification of the relative contents of Proto, Mg-PME, PChlide, and Chlide in Synechocystis cells harvested at an OD730 of 0.4. Chl precursors were extracted with alkaline acetone and quantified by a combination of high-performance liquid chromatography and spectrofluorometry. Values represent mean ± standard deviations from three separate extractions. (C) Absorbance spectra of the precipitate isolated from the growth medium of ΔH324 (solid line) and WTzeo (short dash). The WT accumulated undetectable amounts of Proto. The inset shows the absorbance of 10 μM Proto standard diluted in the same solution.