Fungal and Mixed Microbial Colonization on Heritage Stone Surfaces in Gujarat: A Comparative Study of Queens Mosque, The Associated Tomb, and Rani-Ki-Vav

Abstract

Biodeterioration of heritage stone surfaces is a natural process that occurs when fungi, cyanobacteria, algae, lichens, and bryophytes become ecological interfaces between the stone and the environment and interact with the substrate under varying conditions. Recent studies in heritage microbiology demonstrate that these colonizers are not single entities but form mixed microbial communities, affecting moisture retention, staining, mineral changes, and long-term stone decay. In the present study, fungal and mixed microbial colonization on three important monuments of Gujarat, Queens Mosque, Sarangpur, Ahmedabad (associated tomb near Queens Mosque), and Rani-ki-Vav, Patan, was compared. The goals were to determine the predominant colonizers, compare colonization patterns among the monuments, and evaluate the impact of environmental and architectural factors on biodeterioration. A descriptive, analytical, and diagnostic methodology was applied, including field survey, visual documentation, selective sampling, laboratory isolation of culturable fungi, and comparative ecological interpretation. The results revealed significant differences in fungal and mixed microbial colonization between the urban mosque-tomb complex and the humid stepwell setting. Dark fungal staining and dust-associated mixed films were the dominant features at Queens Mosque and the associated tomb, Sarangpur, Ahmedabad whereas greater development of green films, biofilms, lichenic incrustation, and bryophytic patches in shaded and damp recesses was observed at Rani-ki-Vav, Patan. Fungal isolates from the mosque-tomb complex comprised Aspergillus niger, Aspergillus sydowii, Penicillium citrinum, Fusarium sp., and Memnoniella levispora, with Aspergillus niger being the most common taxon cultured. The study concludes that biodeterioration of Gujarat’s heritage stone is community-based, microhabitat-dependent, and materially significant, requiring site-specific conservation planning.