Original paper
Epilithic blue-green algae/cyanobacteria from temples of India and Nepal. Presence of UV sunscreen pigments
Roy, Amarpalli; Tripathy, Prarima; Adhikary, Siba P.
Algological Studies/Archiv für Hydrobiologie, Supplement Volumes No. 86 (1997), p. 147 - 161
31 references
published: Oct 19, 1997
DOI: 10.1127/algol_stud/86/1997/147
ArtNo. ESP142012000010, Price: 29.00 €
Abstract
The blackish brown crust/tufts occurring on the rock surface of 3 different temples exposed to intense solar radiation absorbed water soon after wetting and became saturated within 2 to 4 hours. Photosynthesis and respiration started within 10 min of wetting and reached maximum activity in about 24 hours suggesting that the internal structure of Tolypothrix sp. and Lyngbya sp. which are the dominant component of the crust/tufts, remained without damage even after exposure to strong insolation. Methanolic extracts (20%, v/v, 45 °C, 2h or 90%, v/v, 25 °C, 3h) of all these organisms in dry state and after wetting absorbed prominently in the UV region of the spectrum. Absorption maxima at 258-260, 312, 317 or 325 nm in all the crust/tufts was due to presence of mycosporine amino acid (MAA)-like compounds. An absorption peak at 384 nm, obtained in the crust of Sun temple, Konark and in the tuft of Kedar Gouri temple, Bhubaneswar containing 2 different species of Tolypothrix, was due to yellowish brown scytonemin pigment. Methanolic extracts of 44 species of blue-green algae (belong to 12 genera) isolated from the crusts/tufts occurring on the rock surface of temples and monuments of various regions of India and Nepal and grown in unialgal culture under fluorescent light revealed that 12 species contained one or more MAAs absorbing in the UV-B and UV-C region. Nine species belonging to Tolypothrix and Calothrix, all of which possessed distinct sheath around their trichome, absorbed strongly in the UV-A region due to the extracellular sunscreen pigment scytonemin.
Keywords
Blue-green algae • temple wall • extreme environment • water uptake • photosythesis • respiration • scytonemin • MAAs • UV sunscreen pigment