Metabolomic analysis of photosynthetic biofilms on building facades in temperate climate zones

The aim of the study was to incorporate a multidimensional approach to the biodeteriorative influence of aerophytic algal biofilms colonising building materials, such as bricks and plasters in temperature climate zones. Stichococcus sp., Klebsormidium sp., Chlorococcum infusionum, Chlorella vulgaris and Pseudochlorella signiensis were detected in green biofilms covering internal and external walls of buildings in Poland. Their growth led to changes in the material's colour in the range of Delta E = 10.82-37.67, as well high water retention and absorptivity. The moisture content of analysed materials ranged from 9.00 to 14.59%. Further, the direct influence of algal growth on the mechanical properties of the analysed materials was not found. For metabolome analysis laser desorption/ionisation time-of-flight mass spectrometry with silver-109 and gold nanoparticles was used. Derivatives of sulfuric compounds and organic acids were detected but this was not the case for metabolites with well-documented biodeteriorative potential. (AgNPET)-Ag-109 LDI MS allowed for the detection of 43 different metabolic pathways, using AuNPET LDI MS 25 pathways. In total, 110 metabolites were found. Although the spectrum of metabolites detected using (AgNPET)-Ag-109 LDI MS was broader, AuNPET LDI MS allowed for the detection of pathways that were not found by (AgNPET)-Ag-109 LDI MS. The combination of both methods allowed for the widest range of results.

Automated summary

The aim of this study was to investigate the biodeteriorative influence of algal biofilms on building materials. The growth of algae led to changes in material color and increased water retention. However, it did not directly affect the mechanical properties of the materials. Metabolome analysis revealed the presence of various metabolites, but not those with well-documented biodeteriorative potential.