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An early-branching microbialite cyanobacterium forms intracellular carbonates.

Abstract

Cyanobacteria have affected major geochemical cycles (carbon, nitrogen, and oxygen) on Earth for billions of years. In particular, they have played a major role in the formation of calcium carbonates (i.e., calcification), which has been considered to be an extracellular process. We identified a cyanobacterium in modern microbialites in Lake Alchichica (Mexico) that forms intracellular amorphous calcium-magnesium-strontium-barium carbonate inclusions about 270 nanometers in average diameter, revealing an unexplored pathway for calcification. Phylogenetic analyses place this cyanobacterium within the deeply divergent order Gloeobacterales. The chemical composition and structure of the intracellular precipitates suggest some level of cellular control on the biomineralization process. This discovery expands the diversity of organisms capable of forming amorphous calcium carbonates.

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  • Authors

    Couradeau E, Benzerara K, Gérard E, Moreira D, Bernard S, Brown GE, López-García P

    Source

    Science (New York, N.Y.) 336:6080 2012 Apr 27 pg 459-62

    MeSH

    Barium
    Base Sequence
    Biofilms
    Calcification, Physiologic
    Calcium
    Calcium Carbonate
    Carbonates
    Chemical Precipitation
    Cyanobacteria
    Genes, Bacterial
    Genes, rRNA
    Inclusion Bodies
    Lakes
    Magnesium
    Mexico
    Molecular Sequence Data
    Phylogeny
    Strontium

    Pub Type(s)

    Journal Article
    Research Support, Non-U.S. Gov't
    Research Support, U.S. Gov't, Non-P.H.S.

    Language

    eng

    PubMed ID

    22539718