The researchers developed tools and methodologies to provide conservation and restoration managers with a better understanding of the development of cyanobacteria-dominated biofilms in hypogean sites interested by stone biodeterioration.. New strategies are becaming available for the monitoring and control of rock bio-decay and to predict the development of biofilm-induced damage.
Experimental data provided evidence (a) of the type of damage produced on rock surfaces through biological activity in hypogea and (b) on the identity of the major factors that control the development and growth of biofilms, their biodiversity and function. The combination of all these data was used to construct models of the complexity of the hypogean environment, of deterioration processes, of biofilm architecture and of the biological activity occurring on lithic faces. In addition, the research determined that changing the wavelengths used for illumination caused a decrease in the growth of unwanted cyanobacteria. Furthermore, the development of non-destructive and safety methods for monitoring of cyanobacterial biofilms was accomplished through the construction of a "Portable Sensor Monitor" holding together different microsensors for the measurement of threshold values of chemical species on endangered stones, and the establishment of a promising new methodology based on the use of a portable spectroradiometer to detect phototrophic biofilm development and to monitor growth.
The method includes the study of microorganisms causing decay of lithic surfaces in hypogea. Most of them were identified using new DNA amplification based molecular tools, isolated and characterised in culture.

Innovative Aspects:
Protection and management of the artistic legacy found in hypogean monuments is addressed by a complete multidisciplinary scientific study:

- to characterise the climatic conditions of sites colonised by photosynthetic microbial communities, and to evaluate possible preferences of cyanobacteria and associated microorganisms for specific lithologies;

- to describe the architecture and functioning of biofilms built by cyanobacteria and associated microorganisms on different types of lithic surfaces;

- to ascertain the most critical physical, chemical and biological factors that control colonisation of rock surfaces;

- to develop new physical methods to control and prevent biofilm growth using wavelengths in the visible part of the light spectrum that are, at best, poorly used by photosynthesis;

- to develop a monitoring method based on a multiparametric microsensor device to assess and quantify the damage caused by photosynthetic biofilms to stone.

Main advantage of the proposed methods are:

- the understanding of biotransformation and biodecay processes of lithic substrata caused by the growth of biofilm-forming photosynthetic micro-organisms on monuments;
- the use of non-distructive portable spectroriadometry to monitor biofilm development;
- the applicability of a physical strategy based on monochromatic lighting to decrease the growth of phototrophic and associated heterotrophic micro-organisms that cause severe damage to valuable rock surfaces in archaeological hypogea;
- the use of a non-invasive sensor-based portable tool for the monitoring of stone damage.

 

Patents/Rights: Secret know-how

Type of Organisation: