Protection of energy transfer process in isolated phycobilisome by 'white light' from ultraviolet-B induced damage in the cyanobacterium Spirulina platensis

Abstract

Effect of UV-B (1.9 W m-2) alone or in combination with supplemental 'white light', WL (20 W m-2) exposure was studied on the energy transfer process of intact phycobilisomes isolated from Spirulina platensis. Exposure of UV-B or supplemental irradiation induced a decrease in room temperature fluorescence intensity and caused a shift towards shorter wavelengths. The low temperature fluorescence measurements showed that UV-B impairs energy transfer from phycocyanin to allophycocyanin B and the extent of damage may be reduced by the exposure to supplemental WL.