Benzerara Karim, Menguy Nicolas, Guyot Francois, Dominici Christian, Gillet Philippe
Laboratoire de Minéralogie-Cristallographie, Unité Mixte de Recherche 7590 Centre National de la Recherche Scientifique and Institut de Physique du Globe de Paris, 4 Place Jussieu, 75252 Paris Cedex, France.
Proc Natl Acad Sci U S A. 2003 Jun 24;100(13):7438-42. doi: 10.1073/pnas.0832464100. Epub 2003 Jun 5.
Nanobacteria-like objects evidenced at the surface of the orthopyroxenes of the Tataouine meteorite in South Tunisia have been studied by scanning and transmission electron microscopies. A method of micromanipulation has been developed to ensure that exactly the same objects were studied by both methods. We have shown that the nanobacteria-like objects are spatially correlated with filaments of microorganisms that colonized the surface of the meteoritic pyroxene during its 70 years of residence in the aridic Tataouine soil. Depressions of a few micrometers in depth are observed in the pyroxene below the carbonates, indicating preferential dissolution of the pyroxene and calcite precipitation at these locations. The nanobacteria-like small rods that constitute calcium carbonate rosettes are well crystallized calcite single crystals surrounded by a thin amorphous layer of carbonate composition that smoothes the crystal edges and induces rounded shapes. Those morphologies are unusual for calcite single crystals observed in natural samples. A survey of recent literature suggests that the intervention of organic compounds derived from biological activity is likely in their formation.
在突尼斯南部塔塔乌因陨石的斜方辉石表面发现的类纳米细菌物体，已通过扫描电子显微镜和透射电子显微镜进行了研究。已开发出一种显微操作方法，以确保两种方法研究的是完全相同的物体。我们已经表明，类纳米细菌物体在空间上与微生物细丝相关，这些微生物在陨石辉石于干旱的塔塔乌因土壤中停留的70年里，在其表面定殖。在碳酸盐下方的辉石中观察到深度为几微米的凹陷，表明辉石在此处优先溶解，方解石在此处沉淀。构成碳酸钙玫瑰花结的类纳米细菌小棒是结晶良好的方解石单晶，周围有一层薄薄的碳酸盐成分非晶层，该非晶层使晶体边缘光滑并形成圆形。这些形态对于在天然样品中观察到的方解石单晶来说是不寻常的。对近期文献的调查表明，其形成过程中可能有源自生物活性的有机化合物的参与。
