Earth and Planetary Sciences: General Earth and Planetary Sciences
; Environmental Science: General Environmental Science
; Agricultural and Biological Sciences: Ecology, Evolution, Behavior and Systematic
英文摘要:
Until now, descriptions of intracellular biomineralization of amorphous inclusions involving alkaline-earth metal (AEM) carbonates other than calcium have been confined exclusively to cyanobacteria (Couradeau et�al., 2012). Here, we report the first evidence of the presence of intracellular amorphous granules of AEM carbonates (calcium, strontium, and barium) in unicellular eukaryotes. These inclusions, which we have named micropearls, show concentric and oscillatory zoning on a nanometric scale. They are widespread in certain eukaryote phytoplankters of Lake Geneva (Switzerland) and represent a previously unknown type of non-skeletal biomineralization, revealing an unexpected pathway in the geochemical cycle of AEMs. We have identified Tetraselmis cf. cordiformis (Chlorophyta, Prasinophyceae) as being responsible for the formation of one micropearl type containing strontium ([Ca,Sr]CO3), which we also found in a cultured strain of Tetraselmis cordiformis. A different flagellated eukaryotic cell forms barium-rich micropearls [(Ca,Ba)CO3]. The strontium and barium concentrations of both micropearl types are extremely high compared with the undersaturated water of Lake Geneva (the Ba/Ca ratio of the micropearls is up to 800,000 times higher than in the water). This can only be explained by a high biological pre-concentration of these elements. The particular characteristics of the micropearls, along with the presence of organic sulfur-containing compounds—associated with and surrounding the micropearls—strongly suggest the existence of a yet-unreported intracellular biomineralization pathway in eukaryotic micro-organisms. � 2016 John Wiley & Sons Ltd
Department of Earth Sciences, University of Geneva, Geneva, Switzerland; Laboratoire de G�ologie de Lyon, Lyon 1 University, Villeurbanne, France; Institute F.-A. Forel, University of Geneva, Geneva, Switzerland; Microbiology unit, University of Geneva, Geneva, Switzerland; Institute of Geosciences, Friedrich Schiller University Jena, Jena, Germany; Service de l'Ecologie de l'Eau (SECOE), Geneva, Switzerland; Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA, Australia; CARRTEL of Thonon-les-Bains, INRA, Thonon-les-Bains, France
Recommended Citation:
Martignier A.,Pacton M.,Filella M.,et al. Intracellular amorphous carbonates uncover a new biomineralization process in eukaryotes[J]. Geobiology,2017-01-01,15(2)