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生存于微氧、近中性pH环境的铁氧化细菌所形成大量的螺旋柄状或长杆鞘状胞外聚合物有利于沉淀其环境中的铁氧化物,而这些胞外聚合物可被视为其地球微生物学标志.太古代晚期至早元古代的海洋是微氧富铁的环境,因此铁氧化代谢成为当时生物圈的重要组成部分,但与之相关的生物物质及铁矿化记录在经历漫长的地质演化后不可避免的发生变化而难以识别.本研究实验模拟了嗜中性微好氧铁氧化菌席可能经历的成岩作用,通过对比现代铁氧化细菌产生的胞外聚合物及铁氧化物在经历高温-高压前后的变化,揭示了生物物质-矿物体系在成岩作用中可能经历的变化过程.实验结果显示螺旋柄状物和长杆鞘状物以及铁氧化物球状聚合物在100MPa和300℃作用之后,其生物结构特征仍可以识别,表明微生物有机质-铁氧化物混合体系可能在地质记录中被一定程度的保存,为前寒武沉积记录中铁代谢的起源和演化的识别提供了参考.
Iron-oxidizing bacteria that live in micro-oxygen, near-neutral pH environments, form large numbers of helical stem-shaped or long-sheath sheath-like extracellular polymers that favor the precipitation of iron oxides in their environment and these extracellular polymers can be visualized As the symbol of the earth’s microbiology.The marine environment from the Late Paleozoic to the Early Proterozoic was a micro-oxygen rich and iron-rich environment, therefore iron metabolism became an important part of the biosphere at that time, but the related biological materials and iron mineralization were recorded It is difficult to identify the changes that inevitably occur after the long geological evolution.This study simulated the diagenesis that neutrophilic micro-anoxia fermenters may undergo. By comparing the extracellular polymers and iron oxidation produced by modern ferric oxide bacteria The change of biomass before and after experiencing high temperature and high pressure revealed the possible process of diagenesis of biomaterial system.Experimental results show that the ratio of helical handle to long rod sheath and iron oxide spheroidal polymer is about 100MPa and After 300 ℃, its biological structure can still be identified, indicating that the microbial organic matter-iron oxide hybrid system may be preserved to a certain degree in the geological record. Pre-Cambrian sedimentary records of the origin and evolution of iron metabolism provides a reference.