Characterisation of actinomycetes isolated from ancient stone and their potential for deterioration.

Actinomycetes have been isolated from decayed and sound stone samples taken from a tomb site at Tell Basta, Zagazig City, Egypt. A total of 160 isolates have been characterised. The numbers and distribution of actinomycetes were studied during different seasons; during the winter months (18-20 degrees C), actinomycete numbers ranged from 10(3) to 10(4) cfu/g; in the summer (28-38 degrees C) lower counts were recorded.