Role of black fungi in color change and biodeterioration of antique marbles

Abstract

Blackening of rock and architectural surfaces by soot and dust has attracted attention of scientists and conservators for some time. Blackening of such substrates by dematiaceous yeastlike fungi, however, has practically never been reported so far. Black fungi and especially meristematically growing yeastlike forms have been known instead as human, animal, and plant pathogenic organisms. Recently we found and isolated such fungi in numerous instances from antique marble and historical limestone buildings at the Acropolis of Athens, the island of Corfu, and from sites in Germany, Italy, Portugal, Russia, Crimea, Spain, and Namibia. The so‐called black yeast are slow‐growing and difficult to isolate and identify. Infield observations, culture experiments on marble slices, and further analyses by SEM and EPR, we demonstrated that black fungi play an important role in the destruction of marble and limestone. They are ubiquitous on monuments under certain climatic and microclimatic conditions. The fungi can be...