On the Role of DNA in CaCO3 Biomineralization: Influence on the Kinetics, Mesoscale Structure, and Morphology of Biogenic Minerals

The role of extracellular DNA in calcium carbonate biomineralization processes is studied using the bacterial culture Bacillus cereus 4B. Different types of DNA, including lysed cell, plasmid, and eukaryotic genomic DNA, are found to significantly affect the kinetics and morphology of calcium carbonate mineral formation. In bacterial systems with varying calcium concentrations, adding cell lysate is shown to accelerate calcium carbonate precipitation and affect the mesoscale structure of aggregates. In an abiogenic system, the addition of plasmid DNA slightly increases the gyration radius of fractal clusters in the crystalline precipitate (from 10.5 to 11.4 nm) and decreases their fractal dimension compared to a system without DNA (from 2.35 to 2.1), while genomic DNA increases it to 2.8. Structural differences in the precipitated minerals suggest that DNA is not only a trigger for biomineralization but also a template for the synthesis of CaCO3 biominerals. This study demonstrates that the molecular characteristics of DNA play a key role in the nucleation, growth, and morphology of mineral structures, opening new perspectives for understanding biomineralization mechanisms.