Decontaminating dental calculus for Paleoculture

Overview & Synopsis

Ancient dental calculus samples are useful for microbial paleoculture, but contamination by Bacillus spp. spores frequently found in old samples can mask other ancient microorganisms of interest. This work aims to develop a specific decontamination protocol for Bacillus spp. based on the use of glycolytic enzymes. It was developed and evaluated on a strain of Bacillus subtilis previously isolated in paleoculture. The effectiveness of the protocol was then tested on five samples of historical dental calculus. The application of the enzymatic protocol demonstrated a complete elimination of Bacillus subtilis. Regarding the samples of ancient dental calculus, the protocol induced a complete elimination of the genus Bacillus spp. This action led to the successful isolation of other bacterial species such as Micrococcus luteus, Staphylococcus haemolyticus and Staphylococcus hominis. The enzymatic approach, targeting specific metabolic pathways, effectively eliminates external contaminants, including bacteria of the genus Bacillus, thus improving the reliability of analyses.