Due to urease activity, bacteria are able to use urea as a sole nitrogen source and produce ammonia, which increases the pH in the proximal environment, causing Ca2+ and CO32- to precipitate as CaCO3.
Ureolytic bacteria hydrolyze urea to generate ATP by the efflux of ammonium ions through ATP-synthase, producing carbonate. In the presence of calcium ions in excess, calcium carbonate will precipitate. biocementation conditions which are reported in the literature for the production of CaCO 3 .
