ABSTRACT
Weathering of minerals in stone monuments is a continuous process that endangers the survival of the world’s historical heritage. The phenomenon has been recognized and observed for many years, but it was not until this century, in fact only in the last 30 years, that conservation came to be a matter of concern. The need to preserve objects and monuments of historical value led first to a study of the causes and mechanisms involved in the deterioration, and the term biodeterioration came to define the role of microorganisms—mainly fungi, bacteria and lichens—in the stone (Webley et al., 1963; Pochon and Jaton, 1968; Williams and Rudolph, 1974; Strzelczyk, 1981; de la Torre et al., 1991b).
