Biodeterioration of Salón de Reinos, Museo Nacional del Prado, Madrid, Spain

Abstract

The Salón de Reinos, a remnant of the 17th century Palacio del Buen Retiro, was built as a recreational residence under the reign of Felipe IV between 1632 and 1640 and was the main room for the monarch’s receptions. This Salón owes its name to the fact that the coats of arms (shields) of the 24 kingdoms that formed Spain in Felipe IV’s time were painted on the vault, above the windows. In addition, the ceiling shows an original decorative composition. The painted ceiling and window vaults showed deterioration evidenced by fissures, water filtration, detachments of the paint layer, and black stains denoting fungal colonization related to humidity. Ten strains of bacteria and 14 strains of fungi were isolated from the deteriorated paintings. Their biodeteriorative profiles were detected through plate assays. The most frequent metabolic functions were proteolytic and lipolytic activities. Other activities, such as the solubilization of gypsum and calcite and the production of acids, were infrequent among the isolates.