Thin-layer chromatography of pigments of the green photosynthetic bacterium Prosthecochloris aestuarii

Abstract

A qualitative analysis was made by thin-layer chromatography of the pigment composition of two photochemically active pigment-protein complexes from the green bacterium Prosthecochloris aestuarii. Both complexes were devoid of bacteriochlorophyll c, the most abundant pigment in intact cells, but contained bacteriochlorophyll a, several carotenoids, bacteriopheophytin c and an as yet unidentified pigment which is probably a pheophytin. The main maxima in the absorption spectrum of the latter pigment in acetone were at 411 and 665 nm; in addition, there were weak bands at 505, 535 and 605 nm. Fluorescence was emitted in a fairly broad band at 670 nm at room temperature and at 675 nm at 4 K. Two major carotenoids were detected, with absorption maxima in light petroleum at 490, 460 and 435 nm and at 503, 473 and 445 nm, respectively. The first one is probably chlorobactene or its hydroxyl derivative. The second one is probably a hydroxyl derivative of rhodopin or lycopene. In addition, at least three other carotenoids were observed in small amounts.