Assessment of biological colonization of historic buildings in the former Auschwitz II-Birkenau concentration camp.

The objective of this study was to assess biological colonization of wooden and brick buildings in the former Auschwitz II-Birkenau concentration camp, and to identify the organisms colonizing the examined buildings. Microbiological analysis did not reveal increased microbial activity, and the total microbial count of the barrack surfaces did not exceed 10 CFU/100 cm. However, certain symptoms of biodegradation of the buildings were observed. The predominant microflora consisted of bacteria of the genera , , , , , and , as well as fungi of the genera , , , , , and . The microflora patterns varied both in wooden and brick buildings. The structural elements of wooden and brick barracks, and especially of the floors and lower parts of bathroom walls, were infected by cyanobacteria and algae, with the most numerous being cyanobacteria of the genera , , , , diatoms of the genus , and chlorophytes of the genera and . The outer surfaces of the examined buildings were primarily colonized by lichens and bryophytes, with nearly 30 species identified. The dominant species of lichens belonged to the genera , , , , , , and , and those of bryophytes to the genera , , , and . The quantity and species diversity of lichens and mosses were much lower in wooden barracks than in brick ones. The external surfaces of those barracks were only affected by , , cf. , and . The study results revealed vast biodiversity among the species colonizing historic buildings. The presence of these groups of organisms, resulting from their natural expansion in the environment, is undesirable, as their excessive growth and spread may lead to progressive biodegradation of buildings. Our assessment of biological contamination will enable the development of a disinfection and conservation plan for the examined buildings.