Bacterial Communities on Degraded Prehistoric Rock Paintings in Maros-Pangkep Global Geopark

Abstract

391 Bacterial Communities on Degraded Prehistoric Rock Paintings in Maros-Pangkep Global Geopark Nur Haedar1*, Muhammad Iqram1, Ambeng1, Yusriana2, Dody Priosambodo1, and Rustan Lebe3 1Biology Department, Faculty of Mathematics and Natural Sciences, Hasanuddin University, Makassar 90245 Indonesia 2Archaeology Department, Faculty of Cultural Science, Hasanuddin University, Makassar 90245 Indonesia 3Indonesian Heritage Agency, Ministry of Education, Culture, Research, and Technology, Jakarta 10110 Indonesia The Maros-Pangkep karst region is a natural landscape located inside the UNESCO Global Geopark, extending across two regencies in South Sulawesi. There are at least 135 prehistoric caves, of which about 78 of them still have traces of relics in the form of rock paintings. One thing that has made this region renowned is the presence of the world’s oldest ancient rock painting, ca. 40,000 years old, in an ancient cave. Unfortunately, many paintings have been experiencing degradation marked by color changes and exfoliation, which are thought to be partially caused by the colonization of bacterial biofilms. The present study, therefore, aimed to delineate the bacterial diversity of biofilms present in ancient rock paintings. Samples were collected from three different caves in the region and analyzed using Oxford Nanopore Technology, sequencing the full-length 16S rRNA gene (V1–V9 regions). The results showed that Firmicutes was the dominant bacterial taxon in both Leang Jing and Leang Parewe, representing 95 and 82% of the total bacterial community, respectively. In Leang Bulu Sipong, we observed a high relative abundance of both Betaproteobacteria (30%) and Firmicutes (44%). Among the taxa detected, some genera – including Cupriavidus, Bacillus, Lysinibacillus, Paenibacillus, Geobacillus, and Pseudomonas – are linked to the carbonate precipitation and rock weathering, which could give a clue on the role of bacterial activities in corroborating the biodegradation on the ancient rock arts. Despite the result of microbial diversity in the rock paintings, it is necessary to do further study on the mechanism of degradation performed by the bacteria. This will support the effort of local authorities to conserve local heritage aged a thousand years.