Читать книгу Monument Future - Siegfried Siegesmund - Страница 127

Lede stone at Ghent and Berlare were both deteriorated and contained gypsum crusts. The crusts were more elaborate in Ghent with overall a higher content of soluble salts. 16S rRNA gene amplicon sequencing revealed potential stone deteriorating nitrogen and sulphur prokaryotes, especially on the City Hall. This suggests a positive correlation with air pollution. However, they were only present with a low concentration in some samples and absent in the isolates. Currently, a strong effect of prokaryotes on crust formation is not expected. Furthermore with decreasing sulphur pollutions, the gypsum is mainly a result of historical accumulation. on Lede stone, prokaryotes can have an impact on the appearance of the monuments as Arthrobacter agilis successfully discoloured Savonnières limestone.