Bioconsolidation on Stone Cultural Heritage Surfaces by Bacteria

Stone-based cultural heritage undergoes progressive deterioration due to natural weathering, pollution, salt crystallization, moisture fluctuations, and biodeterioration. Traditional chemical consolidants often show limited compatibility, aesthetic changes, pore blockages, internal cracking, and irreversible alterations. These limitations have led to increasing interest in bacterial bioconsolidation based on the Microbiologically Induced Carbonate Precipitation (MICP) approach. Such bacteria being either indigenous or non-native species had been reported to precipitate calcium carbonate mineralogically similar to the original stone substrate. This enables the internal consolidation, crack sealing, reduced porosity, and mechanical strength enhancement on the treated surface. As had been observed in multiple studies and in situ applications worldwide, these carbonatogenic phenomena had been reported to produce stable calcium carbonate polymorphs, with enhanced cohesion and durability and reduced water permeability. This review focuses on recent advances in bacterial bioconsolidation, underlying mechanisms, compares its performance with conventional consolidants, and identifies future directions for research and application in cultural heritage conservation.