The Existence of Chlorophyll c in the Chl b-Containing,Light-Harvesting Complex of the Green Alga Mantoniella squamata (Prasinophyceae)

The prasinophycean alga Mantoniella contains, in addition to Chl a and b, at least a third green pigment which is functionally active in the light-harvesting antenna. This third Chl was isolated in order to elucidate its chemical structure. The absorption and fluorescence spectra were measured not only from the purified pigment but also from its pheophytin and its methylpheophorbide. The spectra were compared with those of authentic Chl c-1 and c-2, which were isolated from the diatom Nitzschia sp. and with Mg-DVPP (purified from Rhodobacter). The results show that the pigment from Mantoniella compares best with Chl c-1. In order to clarify the spectral data, Chl c-1 and c-2, Mg-DVPP, and the pigment from Mantoniella were subjected to a chromatographic system that is able to separate these porphyrins. The chromatographic analysis clearly shows that the pigment from Mantoniella co-migrates with Chl c-1 and not with the bacterial pigment. Mantoniella is the first organism which has been demonstrated to contain Chl a, b, and authentic c.