Contribution

Photoacclimation of sciaphilous epilithic cyanobacteria isolated from Roman hypogea

Bruno, Laura; Albertano, Patrizia

Abstract

Three strains of a red Leptolyngbya sp. were isolated from the phototrophic microbial communities colonising Roman hypogea and investigated for their ability to acclimate to varying light regimes. Photosynthesis versus irradiance (P/I) curves were determined for these strains grown at low and high photon flux densities. All the strains appeared to be well adapted to low light regimes, performing an efficient oxygenic photosynthesis at the lowest irradiances. In addition they were able to acclimate to higher light condition increasing the R, and values but reducing the photosynthetic efficiency. Pigment content and cell ultrastructure were also influenced by the acclimation process.

Mots-clefs

Acclimation cyanobacteria • Leptolyngbya P/I curves • pigments • ultrastructure