Nucleation of calcium carbonate on bacterial nanoglobules
Nucleation of calcium carbonate on bacterial nanoglobules
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DOI：
10.1130/g22986a.1
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发表时间：
2006-12-01
期刊：
影响因子：
5.8
通讯作者：
Zuddas, P.
中科院分区：
文献类型：
--
作者：
Aloisi, G.;Gloter, A.;Zuddas, P.
碳酸钙在微生物细胞物质上成核可能是地球历史上大部分时间微生物碳酸盐形成的主要模式。目前的知识预测成核发生在细胞表面或细胞外聚合物质上。然而，最初的成核步骤还没有详细描述，过程仍然难以捉摸。在这里，我们描述了在纳米尺度上碳酸钙的细菌成核。在硫酸盐还原菌（SRB）沉淀实验中，大量碳酸钙沉淀在数百个直径60- 200nm的单个球上。小球起源于SRB细胞表面，但只有在释放到培养基中时才会显着钙化。在其他细菌沉淀实验和许多天然微生物碳酸盐中，已经观察到类似的小球，尽管规模更大，这表明我们描述的过程可能是微生物钙化的重要一步。
Nucleation of calcium carbonate on microbial cell material may have been the dominant mode of microbial carbonate formation during most of Earth's history. Current knowledge predicts that nucleation takes place on the cell surface or on extracellular polymeric substances. However, the initial nucleation steps have not been described in detail and the process remains elusive. Here we describe the bacterial nucleation of calcium carbonate at the nanometer scale. In our precipitation experiment with sulfate reducing bacteria (SRB), the bulk of calcium carbonate precipitates on hundreds of individual globules 60-200 nm in diameter. Globules originate from the SRB cell surface but calcify significantly only when released to the culture medium. Similar globules have been observed, albeit at a much larger scale, in other bacterial precipitation experiments and in many natural microbial carbonates, suggesting that the process we describe could be an important step in microbial calcification.