Predicted Dynamic of Biodeterioration in Cultural Heritage Stones Due to Climate Changes in Humid Tropical Regions—A Case Study on the <i>Rhodotorula</i> sp. Yeast

Abstract

The recent global warming started at the end of the 19th century, causing an increase in the average temperature of Earth and posing environmental, social, economic, and cultural repercussions. Much tangible cultural heritage is composed of natural stones, which decay due to the combination of chemical, physical, and biological factors. Biodeterioration leads to a loss of the performance requirements and socio-economic value of stone building materials. In the future, the dynamics of biodeterioration will hypothetically vary. This study aims to shed light on this variation by comparing biodeterioration under historical climatic conditions (1995–2014) with a future scenario defined by the IPCC SSP5-8.5 for the reference period 2080–2099. The material tested is Pedra de Ançã (PA), a candidate for World Heritage Stone. Climatic chambers were used to simulate the historical and predicted environmental conditions. The scope of this investigation is to understand the growth dynamic of the biodeteriogen Rhodotorula sp. and to study the morphological and aesthetic variations of stone surfaces. Biochemical and micro-topographic analyses highlighted the metabolic activity of the population proliferating under distinct environmental conditions, revealing better adaptability of Rhodotorula sp. and higher biocorrosion in the historical climate status with respect to the future.

Keywords

• limestone
• Pedra de Ançã
• global warming
• world heritage stone
• carbon dioxide
• relative humidity