Diversity of algae and cyanobacteria growing on building facades in France

Abstract

Algae and cyanobacteria in biofilms cause discolouration of the buiding surfaces they colonise.In France, a comprehensive study of the diversity of the species involved in this phenomenon is lacking.73 samples were therefore realised around France and analysed for their micro-organisms composition.Green algae were the most frequent organisms encountered, with Klebsormidium flaccidum (53%), Trebouxia spp.(51%), Stichococcus bacillaris (45%), Chlorosarcinopsis minor (27%) and Chlorella cf.mirabilis (26%) being the most abundant ones.Colonial cyanobacteria were then mainly represented by Cyanosarcina parthenonensis (27%), Chroococcus lithophilus (21%), Gloeocapsa sanguinea (15%) and filamentous cyanobacteria by Calothrix pulvinata (21%), Leptolyngbya foveolarum (18%) and Phormidium corium (12%).