Bio deteriorating microorganism of two archaeological buildings at the site of Uxmal, Mexico

摘要

Several types of microorganisms are strongly involved in the rock decay of monuments of cultural heritage. Microbial colonization is conditioned by environmental factors such as climatic variables (relative humidity, temperature) as well as by natural and anthropogenic pollution. Microbial colonizers of monument walls are often heterotrophic bacteria, cyanobacteria, algae and fungi. Two different sites for sampling were chosen at the archaeological site of Uxmal in the Yucatan peninsula, Mexico. One of the sites was a rock wall exposed to open air, rain and sunlight. The rocks appeared partially covered by a thick black crust. The other sampling site was located at one of the stone walls of an inner chamber of the Governors house. This wall was in a dark room, protected from the sunlight, rain and outer air. In this case the coverage found was thick and predominantly dark green colored. heterotrophic bacteria (Bacillus sp., Pseudomonas sp.), cyanophyta (Cyanosystis sp.) and different fungi were isolated and taxonomically classified. Crust deposits were observed by using stereoscopic magnifier, Scanning Electron Microscopy (SEM) or Environmental Scanning Microscope (ESEM). Possible mechanisms of rock decay based on the type of microorganisms isolated, physicochemical characteristics of the constructional materials, and environmental factors are discussed. (Author)