DETERIOGENIC EFFECT OF MICROBIAL COLONIZATION OF PREHISTORIC PAINTINGS IN MAGOURA CAVE, BULGARIA
MILENA MITOVA*, MICHAIL ILIEV, RALITSA ANGELOVA, VENETA GROUDEVA
Department of General and Industrial Microbiology, Faculty of Biology, Sofia University “St. Kliment Ohridski”, Sofia, Bulgaria
*Corresponding author: mmitowa@abv.bg
Keywords: Biodeterioration effect, microbial colonization, paintings, Magoura cave
Abstract: The Magoura Cave is located in North-Western Bulgaria. The cave contained an impressive display of prehistoric paintings, made by the guano faeces of cave dwelling bats. Many different types of microorganisms may grow on such substrates under favourable environmental conditions and have a biodeterioration effect on the paintings.
The aim of the present study is focused on complete characterization of the microbial communities inhabiting the Magoura cave and determination of the most active biodeteriogens.
The comparative analysis of the microbial colonization clearly demonstrates that each sample possesses unique microbial population structure and specific ratios between different target groups.
The monitoring studies reveal that in the cave present continuously stable microbial population with steady qualitative and quantitative composition. In some samples high levels of sulphate-reducing bacteria, denitrifying and ammonifying bacteria as well as silicate bacteria were found. Some of these bacteria are typical biodeteriogens and it is possible they take part in the destruction of the paintings.
Based on the results obtained, special treatments must be developed for the restriction of the microbial colonization and the conservation of the unique rock paintings.