Using sunlight to protect monuments
Stonehenge, the Acropolis and the Coliseum are just a few of Europe's stone monuments that are synonymous with the region's history and culture. Unfortunately, many of these treasures are under attack from biofilms. Biofilms are thin layers of microorganisms, such as cyanobacteria, fungi, algae, etc., that can cause physical degradation and/or loss of aesthetic beauty. Traditional biocides have been used in the past, but when released to the environment these biocides negatively impact other inhabitants of the local ecosystem, including humans. The BIODAM project consortium was charged with devising new, more environmentally-friendly methods of biofilm control. The BIODAM coordinator, Oldenburg University's Institute for Chemistry and Biology of the Marine Environment (ICBM), evaluated several new treatments both separately and in combination. The methods include: low intensity biocides, inhibitors, permeabilisers and photodynamics, special substances activated by sunlight. ICBM exposed different biofilm-inducing microorganisms to the various treatments in vitro and on stone and painted plaster substrates. Over two years of experimental research performed during BIODAM revealed the power of combining different treatments, in particular the photodynamic components. In the next phase of research, ICBM and its partners will apply the new methods to real monuments and statues.