异化铁还原菌与有机粘土矿物相互作用实验研究
发布时间：2018-07-16 07:46
【摘要】：铁作为地壳中丰度第四的元素广泛存在于土壤、沉积物、沉积岩里的粘土矿物中。粘土矿物由于其巨大的比表面积、表面活性以及阳离子交换能力,通常与沉积物中的有机质结合在一起。粘土矿物通过对陆地环境中有机质的吸附、富集和埋藏,对大气中氧的上升起到了非常中要的作用。微生物是地表铁循环的核心参与者,以细胞体外发生铁的氧化还原反应为特征的异化作用是自然界铁循环的重要驱动力。研究微生物与有机粘土矿物之间的相互作用关系,对于研究Si、Al、Fe和C等重要的化学元素在地质过程中的循环、污染物迁移、有机质埋藏和石油产生方面,都具有重要的意义。本文从微生物的铁还原作用对粘土矿物保存有机质的影响和微生物对粘土矿物中有机质的利用情况两点出发,对微生物与有机质-绿脱石复合体相互作用进行了初步探索。在微生物的铁还原作用对粘土矿物保存有机质的影响实验中,选择有机质12-氨基十二酸(ALA)插层到绿脱石NAu-2中,合成有机粘土ALA-NAu-2,与高温菌Thermus scotoductus SA-01(65 oC)和超高温菌Geoglobus ahangari(85 oC)分别进行微生物与有机粘土矿物相互作用研究。实验结果表明有机质进入粘土矿物层间后抑制了微生物对结构Fe(Ⅲ)的还原。经过微生物作用后,粘土矿物发生还原溶解,层间有机质随着不断从粘土矿物中释放出来,由于微生物还原能力有限(30%),总体来说有机质在粘土矿物中可以得到很好的保存。超高温环境相对于高温环境有机质释放的含量较多,表明温度越高越不利于有机质的保存。在微生物对绿脱石中有机质利用的研究实验中,选取嗜热菌Thermus scotoductus SA-01(65℃),以及常温菌Shewanella putrefaciens CN32(30℃)为异化铁还原菌,分别在没有外加碳源的情况下对NAu-2结构铁进行还原。实验结果表明相对于常温菌CN-32,嗜热菌SA-01可以有效利用绿脱石中含有的微量有机质作为碳源。由此可知,粘土矿物经微生物作用后发生还原溶解,其吸附的有机质会随着溶解程度的升高不断释放到周围环境中;粘土矿物含有的有机质组分成分复杂,在不同温度环境下释放出来的有机质速率与种类有所不同。
[Abstract]:Iron, the fourth most abundant element in the crust, is widely found in clay minerals in soils, sediments, and sedimentary rocks. Clay minerals are usually combined with organic matter in sediments due to their large specific surface area, surface activity and cation exchange ability. Clay minerals play a very important role in the increase of oxygen in the atmosphere through the adsorption, enrichment and burial of organic matter in terrestrial environment. Microbes are the core participants in the surface iron cycling. The dissimilation characterized by the redox reaction of iron in the cells in vitro is an important driving force of iron cycling in nature. The study of the interaction between microbes and organic clay minerals is of great significance in the study of the circulation of important chemical elements such as Si-AlFe and C in geological processes, pollutant migration, organic matter burial and petroleum generation. In this paper, the interaction between microorganism and organic matter in clay minerals has been preliminarily explored from two aspects: the effect of iron reduction by microorganisms on the preservation of organic matter in clay minerals and the utilization of organic matter in clay minerals by microorganisms. In the experiment of the effect of microorganism iron reduction on the preservation of organic matter in clay minerals, the organic matter 12-amindodecanoic acid (Ala) was intercalated into the green demineralized NAu-2. The organic clay ALA-NAu-2 was synthesized, and the interaction between microbes and organic clay minerals was studied with Thermus scotoductus SA-01 (65oC) and Geoglobus ahangari (85oC), respectively. The results show that organic matter can inhibit the reduction of structural Fe (鈪，
本文编号：2125721
[Abstract]:Iron, the fourth most abundant element in the crust, is widely found in clay minerals in soils, sediments, and sedimentary rocks. Clay minerals are usually combined with organic matter in sediments due to their large specific surface area, surface activity and cation exchange ability. Clay minerals play a very important role in the increase of oxygen in the atmosphere through the adsorption, enrichment and burial of organic matter in terrestrial environment. Microbes are the core participants in the surface iron cycling. The dissimilation characterized by the redox reaction of iron in the cells in vitro is an important driving force of iron cycling in nature. The study of the interaction between microbes and organic clay minerals is of great significance in the study of the circulation of important chemical elements such as Si-AlFe and C in geological processes, pollutant migration, organic matter burial and petroleum generation. In this paper, the interaction between microorganism and organic matter in clay minerals has been preliminarily explored from two aspects: the effect of iron reduction by microorganisms on the preservation of organic matter in clay minerals and the utilization of organic matter in clay minerals by microorganisms. In the experiment of the effect of microorganism iron reduction on the preservation of organic matter in clay minerals, the organic matter 12-amindodecanoic acid (Ala) was intercalated into the green demineralized NAu-2. The organic clay ALA-NAu-2 was synthesized, and the interaction between microbes and organic clay minerals was studied with Thermus scotoductus SA-01 (65oC) and Geoglobus ahangari (85oC), respectively. The results show that organic matter can inhibit the reduction of structural Fe (鈪，
本文编号：2125721
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