Carotenoids and ubiquinone in aerobically grown cells of an aerobic photosynthetic bacterium, Erythrobacter species OCh 114.

Abstract

Carotenoids and ubiquinone in aerobically grown cells of Erythrobacter species OCh1 14 were identified, which contained a considerable amount of bacteriochlorophyll α mediating light-driven electron flows. Spheroidenone was found to be the major component of carotenoids. Also small amounts of 2, 2'-diketospirilloxanthin and OH-spheroidenone were found. Since symmetrical ζ-carotene (together with phytoene and phytofluene) was accumulated in diphenylamine-inhibited cultures, these 3 keto carotenoids of the alternative spirilloxanthin-series are considered to be synthesized mainly via symmetrical ζ-carotene and not through asymmetrical ζ-carotene which is knownto be the intermediate in the biosynthesis of carotenoids in somespecies of non-sulfur purple bacteria. Onthe other hand, the major (or the sole) respiratory quinone of this strain was found to be ubiquinone-10.