ABSTRACT
The use of lamps for lighting indoor archaeological or historical sites is crucial for the development of photo synthetic microorganisms able to make use of different types of light qualities and intensities. Light influences several aspects of the life of photosynthetic organisms, but is fundamental to allow the transformation of physical energy and inorganic compounds into living biomass. The former involve light energy capture by photosynthetic pigments and the transfer of this energy to ATP and NADPH. Dim light habitats like caves, necropolis and catacombs, are characterised by stable climatic conditions, and terrestrial epilithic cyanobacteria and few eukaryotic algae develop therein along light gradients and according to the biosusceptibility of substrata. “Light” refers to wavelenghts of the electromagnetic spectrum that are visible to the human eye plus the ultraviolet and infrared bands. In Roman hypogea, almost all visible wavelenghts emitted by the lighting systems are absorbed by cyanobacterial-dominated biofilms.
