Figure 6.

Analysis of heme/chlorophyll precursors in the P(petJ)::hemJ strain grown photoautotrophically in medium with or without copper. Heme/chlorophyll precursors were extracted with 70% methanol from the P(petJ)::hemJ cells at OD₇₃₀ = 0.3–0.4 and separated on a HPLC equipped with two fluorescence detectors (48). The amounts of later chlorophyll precursors magnesium-protoporphyrin IX (MgP) and monovinyl protochlorophyllide (PChlide) were markedly reduced in cells cultivated with the repressed hemJ expression when compared with the same mutant cells grown without copper. On the contrary, Proto and Copro massively accumulated in the repressed cells. The inset shows a different scale for the less abundant precursors. *, significance difference tested using a paired t test (p = 0.05).