Acaryochloris marina MBIC11017

Cyanobacteria are oxygenic, phototrophic organisms. They encode two photosystems (PSI and PSII) releasing electrons from water and fix carbon dioxide via the Calvin-Benson-Bassham pathway. Thus they absorb large quantities of C(O)2 and produce (O)2. Some cyanobacteria are also able to fix (N)2.This cyanobacterium was first collected from a colonial ascidian from the Palau Islands; it has since been collected as a free-living organism in Japan and the USA. It is unusual in containing chlorophyll d as the major (95%) and chlorophyll a as the minor (5%) photosynthetic pigments with phycocyanin and trace amounts of chlorophyll c. Oxygenic photosynthesis based on chlorophyll d may have evolved as an acclimatization to far-red light environments, or an as intermediate between the red-absorbing oxygenic and the far-red-absorbing anoxygenic photosynthesis that uses bacteriochlorophylls. Because of the unusual ratio of chlorophyll a to chlorophyll d in this organism, it has been used as a model to study the spectrographic characteristics of the two pigments. (HAMAP: ACAM1)