title: Characterisation of actinomycetes isolated from ancient stone and their potential for deterioration.
abstract: 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. The actinomycete isolates were assigned to 4 different taxonomic groups: 54% belonged to the Streptomyces group, 26% to the Nocardia group, 14% showed the characteristics of the Micromonospora group, while the rest of the isolates analyzed (6%) were assigned to the sporangiate-type group of actinomycetes. The ability of the isolates to produce pigments as well as tolerance to high salinity were determined. It was shown that about 88% of the strains studied had the ability to produce extracellular pigments. Only 25% of the studied isolates showed tolerance to high salinity. The significance of actinomycetes to attack and degrade building stone was shown in laboratory experiments: actinomycetes recovered both from sound and decayed stones were capable of damaging stone under laboratory conditions as an up to 4% weight loss was recorded for some isolates.
authors.affiliation: Botany Department, Faculty of Sciences, Suez Canal University, Ismailia 41522, Egypt. h.abdulla@scuegypt.edu.eg
authors.forename: Hesham
authors.initials: H
authors.lastname: Abdulla
authors.forename: Eric
authors.initials: E
authors.lastname: May
authors.forename: Magdi
authors.initials: M
authors.lastname: Bahgat
authors.forename: Ahmed
authors.initials: A
authors.lastname: Dewedar
mesh_terms: D039903:Actinobacteria / Q000145:classification* / Q000187:drug effects / Q000302:isolation & purification* / Q000378:metabolism; D001106:Archaeology; D002119:Calcium Carbonate; D003252:Construction Materials; D010860:Pigments, Biological / Q000096:biosynthesis; D012965:Sodium Chloride / Q000494:pharmacology; D013172:Spores, Fungal / Q000502:physiology
chemical_list: D010860:Pigments, Biological; D012965:Sodium Chloride; D002119:Calcium Carbonate