| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4364645 | International Biodeterioration & Biodegradation | 2015 | 12 Pages |
•The ability of Bacillus pumilus ACA-DC 4061 to promote biomineralization of calcium carbonate was investigated.•Constant formation of vaterite was identified that remained stable in samples even after a year.•Design of experiments was applied engaging three main factors: temperature, medium and inoculum concentration.•Optimization of obtained statistical model showed that vaterite provided encouraging bioconsolidation results on marble.
In this work, Bacillus pumilus ACA-DC 4061 was selected for its increased capability for biomineralization on marble, under different nutrient media concentrations and temperature conditions. The optimum conditions for the CaCO3 bacterially-induced precipitation were determined with the aid of testing based on the Design of Experiments (DoE). Biomineral (vaterite) precipitation was favored in both the temperatures (25 and 30 °C) investigated. Stone loss rate was reduced when the samples were subjected to sonication. Thin sections of the substrate confirmed that vaterite was able to adhere onto the surface. Finally, under non-sterile conditions mimicking an in situ application, B. pumilus ACA-DC 4061 formed a fine layer of calcium carbonate. Therefore, this microorganism showed that vaterite formation may consistently occur under specific conditions and could prove useful as a candidate for on-site applications for stone conservation.
