Light adaptation of a cyanobacterium, Arthrospira platensis, observed by time-resolved fluorescence spectroscopy

Abstract

Photosynthetic organisms contain specific light-harvesting antenna complexes, which absorb light energy and subsequently transfer excitation energy to the reaction centers where photo-induced electron transfer takes places. Cyanobacteria, which are the most primordial among oxygenic photosynthetic organisms, possess unique antenna complexes, i.e. phycobilisome (PBS). PBS harvests light energies in the visible region, which are inaccessible to chlorophylls, and transfers excitation energy to chlorophylls.
In the present study, we have examined excitation relaxation dynamics in a cyanobacteria, Arthrospira (Spirulina) platensis by means of picosecond time-resolved fluorescence spectroscopy. We will discuss differences in light-harvesting and energy-transfer processes in A. platensis grown under different light conditions.