Microbes Can Damage but Also Help Restore Artifacts

F rom the prefabricated wooden huts of Antarctic explorers in the early 20th century to the enduring limestone ruins of the Mayan city Ek’ Balam (Black Jaguar) built more than 1,200 years ago (Fig. 1), conservators, archaeologists, and other specialists are striving to understand and combat the physical, chemical, and biological processes responsible for the deterioration of these historic structures and artifacts. Each of these sites represents a cultural trove, one as a testament to a lost civilization and the other as a tribute to a bygone era of exploration. Separated by more than 10,000 km and residing in two very different climates, these sites were constructed of drastically different materials. Yet the artifacts at each location are slowly wasting away, presenting two very different cases of biodeterioration that reflect distinct microbial communities and modes of decomposition. With their ability to use diverse energy sources and survive under varied environmental conditions, microorganisms are superbly capable of degrading culturally important materials. Given the proper conditions of humidity, temperature, and pH, many components of our precious cultural heritage such as pigments, textiles, metals, polymers, wood, and stone can fall victim to microbial degradation. Biodeterioration of culturally significant artifacts and structures takes on new levels of importance as conservators and archaeologists weigh the benefits of unearthing and displaying artifacts, or even cleaning or repairing such artifacts, against the risks of exposing them to further damage by microbes.