Biochemical and spectroscopic analysis of the effect of UV on the pigmentation of the red algae Gracilaria dentata, Hypnea musciformis and Centroceras clavulatum

Abstract

Red algae are multicellular organisms that belong to the family Rhodophyceae. Majority of them are found at a depth of 40 m, where only short-wavelength visible light penetrates in any significant intensity and can be absorbed by red algae. The objective of this study was to determine the sensitivity of Gracilaria dentata, Hypnea musciformis and Centroceras clavulatum to components of solar spectrum and their survival. Specifically, effects of UV-A, UV-B and PAR on pigmentations of Gracilaria dentata, Hypnea musciformis and Centroceras clavulatum were investigated under laboratory conditions. Thalli of the algae were exposed either to unfiltered solar radiation or solar radiation filtered through WG 295, WG 320, and GG 400 cut-off filters. Sucrose gradient ultracentrifugation revealed that all the organisms had allophycocyanin as accessory pigment in addition to phycoerythrin and phycocyanin. The phycoerythrin occurred in monomers, trimers, and hexamers.