The objective was to evaluate different apoptosis signals, pigment inhibitors, exopolysaccharide inhibitors, permeabilizers and photodynamic treatments for their "in vitro" effectiveness against bacteria, fungi and algae commonly found in deteriorated stone materials.
Model organisms were selected from those commonly found on deteriorated stone and plaster substrates. Selected photodynamic treatments were screened for effectiveness against algae/cyanobacteria both in vitro and on stone and painted plaster substrates.
The concept of a polyphasic approach to inhibiting detrimental growth of biodeteriorative and or unaesthetic biofilms seems extremely valid after the first two years of experimental approach. The literature reviews have shown clearly a necessity to analyse for and to inhibit biofilm growth on monument mineral materials.
The selection of a few non-toxic or low toxic compounds for cambatting detrimental biofilms was in urgent need. The combination of biocides with permeabilizers and photodynamic treatments turned out as a very promising tool, which now is in the field testing phase. Special compounds, combined with photodynamic activation treatments seem to be a very attractive alternative to costly and environmentally hazardous treatments effected until now in many monuments worldwide.