Diversity of algae and cyanobacteria growing on building façades in France

Abstract

Algae and cyanobacteria in biofilms cause discolouration of the building surfaces they colonise. In France, no comprehensive study of the diversity of the species involved in this phenomenon has up to now been undertaken. 71 samples were therefore collected all over France and analysed for their micro-organisms composition. Green algae were the most frequent organisms encountered, with Klebsormidium flaccidum (55 %), Trebouxia spp. (49 %), Stichococcus bacillaris (46 %), Chlorosarcinopsis minor (28 %) and Chlorella cf. mirabilis (27 %) being the most abundant ones. Colonial cyanobacteria were then mainly represented by Cyanosarcina parthenonensis (28 %), Chroococcus lithophilus (21 %), Gloeocapsa sanguinea (15 %) and filamentous cyanobacteria by Calothrix pulvinata (21 %), Leptolyngbya foveolarum (18 %) and Phormidium corium (13 %).