Monitoring living components in biofilms on construction materials and monitoring signs and effects of biodeterioration

• Research unit: COST
• Project number: C98.0082

Key words (English)

Biofilms; algae; bacteria; fungi; lichens; stone; construction materials; buildings; cultural heritage; biodeterioration

Research programs (English)

COST-Action 520 - Biofouling et matériaux

Short description (English)

See abstract

Further information (English)

Full name of research-institution/enterprise: Eidg. Materialprüfungs- und Forschungsanstalt EMPA Abteilung Biologie

Partners and International Organizations (English)

B, DK, FIN, F, D, GR, H, I, NL, P, RO, SI, E, S, CH, GB

Abstract (English)

The project started in march 1999 by monitoring different sites. Until now - the third year of work - four buildings were inspected several times for surface biocontamination and visual growth. The choice was influenced by the following topics: (1) About fifteen years exposed fibre cement panels on a ventilated cold heat insulated facade showed strong biomats but without microscopically visible signs of deterioration of the coated panels. After the recent restoration, monitoring will be continued for the enlargement of our experience. (2) Areas of the facade of a pioneer fair-faced concrete building showed dark biofilms. Different remedial treatments were recently applied and thus tested. Some parts of the building have already been renewed due to corrosion of iron and concrete. Additionally, the succession of organisms and their possible connection with the corrosion process has to be shown? The last three years of monitoring are reported in two figured atlases of the visible organisms found. (3) Biofilms and crusts by calciumoxalate caused the restoring of an about 350 years old plaster. This offered the possibilities to 1. monitor the existing biofilms before restoration and 2. for long term monitoring the microorganisms which form visible biomats that reappear on the surface in future. In the same cloisture, a monitoring method was validated under the current indoor situation to determine ongoing growth in relation to climatic conditions and the respective development of fungal and bacterial growth. (4) In the cloisture of an old monastery black biofilms developed to strongly visible colonies within a short time. Other areas showed red bacterial biofilms by micrococci. The further behavior has to be monitored and reasons have to be found. The monitoring has to be continued. The main work dealt with monitoring and isolation of pure cultures from the different buildings. Colonies were photographed after defined incubation periods, since one of the aims is the creation of a figured atlas in order to support future fieldwork in this area. Experiments were started to visualize the effects of surface growth on modern building materials such as fibre cement panels and plasters. Furthermore, a laboratory manual including photographs and microscopical characters of lichenes from two different sites has been developed and will be published soon. In summer 2000 we started with an intense monitoring on plaster boards from outdoor weathering experiments. 1.5 years later we registered large differences of growth most possibly depending on the different materials used.

References in databases (English)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C98.0082