The pigments of Prochlorococcus marinus: The presence of divinylchlorophyll a and b in a marine procaryote

Abstract

The pigments of the recently isolated marine prochlorophyte Prochlorococcus marinus were characterized by modern chromatographic and spectroscopic analysis. The major photosynthetic pigment is 8‐desethyl, 8‐vinyl chlorophyll a . Accessory pigments are 8‐desethyl, 8‐vinyl chlorophyll b , zeaxanthin, α ‐carotene, an unknown carotenoid, and possibly Mg 3,8 divinyl‐pheoporphyrin a 5 . Chl a is not present in this organism. P. marinus is the first wild‐type oxygenic phototroph that does not have Chl a as its major photosynthetic pigment and it is the only procaryote ∊ ‐cyclic carotenoids ( α ‐carotene). P. marinus demonstrates a range of biosynthetic abilities that will necessitate a re‐evaluation of the evolution of chlorophyll and carotenoid biosynthesis in pro‐ and eucaryotic phototrophs.