<i>Pseudomonas</i>,<i>Pantoea</i>and<i>Cupriavidus</i>isolates induce calcium carbonate precipitation for biorestoration of ornamental stone

Abstract

AIMS: Bacterially induced calcium carbonate precipitation from various isolates was investigated aiming at developing an environmentally friendly technique for ornamental stone protection and restoration. METHODS AND RESULTS: Micro-organisms isolated from stone samples and identified using 16S rDNA and biochemical tests promoted calcium carbonate precipitation in solid and novel liquid growth media. Biomineral morphology was studied on marble samples with scanning electron microscopy. Most isolates demonstrated specimen weight increase, covering partially or even completely the marble surfaces mainly with vaterite. The conditions under which vaterite precipitated and its stability throughout the experimental runs are presented. CONCLUSIONS: A growth medium that facilitated bacterial growth of different species and promoted biomineralization was formulated. Most isolates induced biomineralization of CaCO3 . Micro-organisms may actually be a milestone in the investigation of vaterite formation facilitating our understanding of geomicrobiological interactions. Pseudomonas, Pantoea and Cupriavidus strains could be candidates for bioconsolidation of ornamental stone protection. SIGNIFICANCE AND IMPACT OF THE STUDY: Characterization of biomineralization capacity of different bacterial species improves understanding of the bacterially induced mineralization processes and enriches the list of candidates for biorestoration applications. Knowledge of biomineral morphology assists in differentiating mineral from biologically induced precipitates.