微生物硅化作用模拟实验

EXPERIMENTAL SIMULATION ON MICROBIAL SILICIFICATION

硅化保存微体化石结构的识别和鉴定一直存在争议,现代人工模拟生物硅化实验有助于对硅化作用保真度(silicification fidelity)等问题的理解。本实验通过人工配置浓度为1000ppm的硅溶液模拟自然硅化环境,观察杆状细菌(bacillus)在该环境中的早期硅化作用。实验发现这种细菌可以在该硅化环境中快速硅化,并较好地保存其形态。硅化细菌表面硅质微颗粒(nano-spheres)沉积明显分两层,紧密规则的内层硅质微颗粒较好地保存了细菌表面结构,外层硅质微颗粒仅保存细菌轮廓。实验结果期望能为硅质细菌类微体化石的鉴别提供有益参考,并为其成因探讨提供更多实证依据。

Controversies occur in identifying silicified microbial structures. The simulated silicification experiment on extant bacillus was carried to benefit further understanding of microbial silicification fidelity. The present experiment reveals that the microbes solidified rapidly and the general morphology is preserved. The silicified microbe was encrusted by double layers of silica nano-spheres. The surface structure of the microbe is preserved in the inner layer, while only the outline of the microbe in the outer layer. The significance of the experiment on identifying silicified microbe fossils and reconstructing silicification environment is discussed.