The Primitive Thylakoid-Less Cyanobacterium Gloeobacter Is a Common Rock-Dwelling Organism
Figure 3
Light spectroscopy analysis of photosynthetic pigments in Aphanothece caldariorum-like strain and Gloeobacter violaceus.
(A) fluorescence emission spectra of A. caldariorum-like strain CCALA 981 in comparison with G. violaceus PCC 7421 for excitation to phycobilisomes. Higher content of phycoerythrin in CCALA 981 is documented by a relative increase in its fluorescence emission at 574nm. (B) and (C) whole cell absorption spectra of CCALA 981 and PCC 7421 normalized to chlorophyll a content. Clear accumulation of carotenoids (wide absorbance peak between 450–500 nm) at the stationary phase of growth (third and fourth batch) is obvious in both strains. The absorbance of 41-day old strain PCC 7421 is raised due to the beginning of accumulation of carotenoids in this batch, but phycobilin peaks are still recognizable. Individual absorbance peaks are as noted; CAR, carotenoids; PE, phycoerythrin; PC+APC, phycocyanin and allophycocyanin; Chl a, chlorophyll a.