@misc{10481/112315,
year = {2009},
url = {https://hdl.handle.net/10481/112315},
abstract = {Microbially mediated high-Mg calcite and dolomite precipitation occurs under
oxic conditions in Brejo do Espinho lagoon, Brazil, within the upper 5 cm below
the sediment–water interface. With burial to < 25 cm in the sediment sequence, early
diagenesis associated with sulphate-reducing bacterial activity transforms the mixed
carbonate mineralogy to 100% dolomite, as the pore-water becomes undersaturated with
respect to calcite, while remaining supersaturated with respect to dolomite. Laboratory
culture experiments using moderately halophilic aerobic bacteria (Virgibacillus
marismortui and Marinobacter sp.) isolated from the uppermost part of the microbial
mat in Brejo do Espinho demonstrate that microbially mediated dolomite precipitation can occur under ambient Earth’s surface conditions in the presence of oxygen.
These results add an additional metabolic process, aerobic respiration, to bacterial
sulphate reduction and methanogenesis, which have previously been identifi ed with
dolomite formation. Furthermore, the formation of carbonate minerals with spherulitic
structures in both the natural environment and laboratory culture experiments points
to microbial involvement, as recognized in numerous other modern environments
and ancient systems. This study suggests that previously recognized modern dolomite-forming environments, such as the supratidal areas of Andros Island, Bahamas,
with recent dolomite crusts should be revisited to evaluate the importance of aerobic
respiration in dolomite precipitation.},
title = {Microbial Dolomite Precipitation under Aerobic Conditions: Results from Brejo do Espinho Lagoon (Brazil) and Culture Experiments},
author = {Sánchez-Román, Mónica and Rivadeneyra, Marian},
}