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为研究阪崎克洛诺菌(Cronobacter Sakazakii)还原普通钙基蒙脱石中Fe3+的过程与机理,测定了体系中总蛋白与Fe2+含量变化,应用同步辐射XRD(SRXRD)与X射线吸收近边结构(XANES)研究反应产物。总蛋白与Fe2+数据表明在厌氧条件下Cronobacter sakazakii以乙酸作为电子供体,利用钙基蒙脱石中Fe3+作为电子受体进行生长代谢,还原蒙脱石中Fe3+形成Fe2+。反应中蒙脱石晶体结构部分破坏,原始的d001峰消失,出现一系列与新生矿物有关的衍射峰。XANES结果显示蒙脱石中Fe主吸收峰向低能量方向移动0.5 e V,边前峰峰位中心向低能量方向移动且峰面积减小,Fe氧化态降低,蒙脱石晶体结构发生变化。研究探讨了自然界中广泛分布的钙基蒙脱石可能受到的微生物还原作用。
In order to study the process and mechanism of reduction of Fe3 + in common calcium-based montmorillonite by Cronobacter Sakazakii, the content of total protein and Fe2 + in the system was measured. The changes of total protein and Fe2 + in the system were measured by X-ray absorption (SRXRD) Structure (XANES) Study reaction products. Total protein and Fe2 + data show that under anaerobic conditions Cronobacter sakazakii with acetic acid as an electron donor, the use of calcium-based montmorillonite Fe3 + as an electron acceptor for growth and metabolism, reducing the formation of Fe3 + montmorillonite Fe2 +. Part of the crystal structure of the montmorillonite reaction is destroyed, the original d001 peak disappears, and a series of diffraction peaks related to the nascent minerals appear. XANES results showed that the main absorption peak of Fe in montmorillonite shifted 0.5 e V to the low energy direction, the center of the front peak decreased toward the lower energy and the peak area decreased, the oxidation state of Fe decreased and the crystal structure of montmorillonite changed. This study explored the possible microbial reduction of calcium-based montmorillonites widely distributed in nature.