Controlling microbial activity on walls by a photocatalytic nanocomposite paint: A field study

Bacteria and fungi grow on walls under suitable conditions. Most frequently isolated bacteria strains on walls include bacillus, nitrifying bacteria, and thiobacillus,1, 2, 3 while those of fungi strains include aspergillus flavus, penicillium and cladospora.4, 5, 6 The growth of those microbial strains requires suitable nutrients levels, i.e., nitrate at 5.30 to 14.83 mg/kg, phosphate at 2.19 to 5.94 mg/kg, sulfate at 12.97 to 19.07 mg/kg, and total organic carbon at 74.89 to 119.43 mg/kg, which are provided by wall paints.