Precipitation of carbonates by Nesterenkonia halobia in liquid media

We investigated the precipitation of carbonates by Nesterenkonia halobia in a liquid medium at different concentrations of salts and incubation times. N. halobia only produced crystals at salt concentrations of 2.5%, 7.5% and 15%. At 20% salt concentration no crystal formation was observed. Calcite, aragonite and dolomite were precipitated in different quantities, dependin g on the salinity of the medium and incubation time. Scanning and transmiss ion electron microscopy, microanalysis and electron diffraction were all us ed to study in detail the morphology, composition and internal structure of the bioliths. We propose a mechanism for biolith formation involving both biological and inorganic processes. (C) 2000 Elsevier Science Ltd. All righ ts reserved.