TY - JOUR
T1 - Processes of carbonate precipitation in modern microbial mats
AU - Dupraz, Christophe
AU - Reid, R. Pamela
AU - Braissant, Olivier
AU - Decho, Alan W.
AU - Norman, R. Sean
AU - Visscher, Pieter T.
N1 - Funding Information:
This review was made possible through projects supported by the Swiss National Fund grant# 200021-108141 to CD and grant# PBNEA-110305 to OB, the US NSF Biocomplexity EAR 0221796 to PR, AD and PV, NSF Biogeosciences EAR 0311929 to PV, and a NASA JRI through AMES research center to PV. This is RIBS contribution #47 and #15 of UConn's Center for Integrative Geosciences. We thank the constructive remarks made by Dr. Jack Farmer and an anonymous reviewer.
PY - 2009/10
Y1 - 2009/10
N2 - Microbial mats are ecosystems that arguably greatly affected the conditions of the biosphere on Earth through geological time. These laminated organosedimentary systems, which date back to > 3.4 Ga bp, are characterized by high metabolic rates, and coupled to this, rapid cycling of major elements on very small (mm-μm) scales. The activity of the mat communities has changed Earth's redox conditions (i.e. oxidation state) through oxygen and hydrogen production. Interpretation of fossil microbial mats and their potential role in alteration of the Earth's geochemical environment is challenging because these mats are generally not well preserved. Preservation of microbial mats in the fossil record can be enhanced through carbonate precipitation, resulting in the formation of lithified mats, or microbialites. Several types of microbially-mediated mineralization can be distinguished, including biologically-induced and biologically influenced mineralization. Biologically-induced mineralization results from the interaction between biological activity and the environment. Biologically-influenced mineralization is defined as passive mineralization of organic matter (biogenic or abiogenic in origin), whose properties influence crystal morphology and composition. We propose to use the term organomineralization sensu lato as an umbrella term encompassing biologically influenced and biologically induced mineralization. Key components of organomineralization sensu lato are the "alkalinity" engine (microbial metabolism and environmental conditions impacting the calcium carbonate saturation index) and an organic matrix comprised of extracellular polymeric substances (EPS), which may provide a template for carbonate nucleation. Here we review the specific role of microbes and the EPS matrix in various mineralization processes and discuss examples of modern aquatic (freshwater, marine and hypersaline) and terrestrial microbialites.
AB - Microbial mats are ecosystems that arguably greatly affected the conditions of the biosphere on Earth through geological time. These laminated organosedimentary systems, which date back to > 3.4 Ga bp, are characterized by high metabolic rates, and coupled to this, rapid cycling of major elements on very small (mm-μm) scales. The activity of the mat communities has changed Earth's redox conditions (i.e. oxidation state) through oxygen and hydrogen production. Interpretation of fossil microbial mats and their potential role in alteration of the Earth's geochemical environment is challenging because these mats are generally not well preserved. Preservation of microbial mats in the fossil record can be enhanced through carbonate precipitation, resulting in the formation of lithified mats, or microbialites. Several types of microbially-mediated mineralization can be distinguished, including biologically-induced and biologically influenced mineralization. Biologically-induced mineralization results from the interaction between biological activity and the environment. Biologically-influenced mineralization is defined as passive mineralization of organic matter (biogenic or abiogenic in origin), whose properties influence crystal morphology and composition. We propose to use the term organomineralization sensu lato as an umbrella term encompassing biologically influenced and biologically induced mineralization. Key components of organomineralization sensu lato are the "alkalinity" engine (microbial metabolism and environmental conditions impacting the calcium carbonate saturation index) and an organic matrix comprised of extracellular polymeric substances (EPS), which may provide a template for carbonate nucleation. Here we review the specific role of microbes and the EPS matrix in various mineralization processes and discuss examples of modern aquatic (freshwater, marine and hypersaline) and terrestrial microbialites.
KW - EPS
KW - biologically-induced mineralization
KW - biologically-influenced mineralization
KW - biomineral
KW - microbial mats
KW - microbialites
KW - organomineral
KW - organomineralization
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U2 - 10.1016/j.earscirev.2008.10.005
DO - 10.1016/j.earscirev.2008.10.005
M3 - Review article
AN - SCOPUS:70349307412
VL - 96
SP - 141
EP - 162
JO - Earth-Science Reviews
JF - Earth-Science Reviews
SN - 0012-8252
IS - 3
ER -