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粘土矿物在地球表层分布广泛,与微生物的交互作用十分常见。微生物能否通过除还原Fe(Ⅲ)之外的其他途径影响贫铁蒙脱石的结构与物相,成为粘土矿物与微生物交互作用的新问题。本研究选取胶质芽孢杆菌Bacillus mucilaginosus 3027与钙基蒙脱石在35℃、常压条件下进行交互作用实验,考察胶质芽孢杆菌生命活动对蒙脱石晶体结构的影响。实验定期取样进行pH值与体系总蛋白含量测试,并利用显微傅里叶变换红外光谱(microFTIR)、同步辐射X射线近边吸收结构(XANES)、X射线衍射(XRD)和扫描电镜(SEM)对最终产物进行矿物学表征。实验结果显示,胶质芽孢杆菌在蒙脱石矿物悬浊液中生长,代谢分泌大量有机酸导致体系pH值降低,使蒙脱石中Si元素溶出,并造成蒙脱石晶体结构中硅氧四面体对称性、O—H振动等发生变化,Fe配位八面体对称性下降,矿物表面出现边缘卷曲现象。在微生物作用后的矿物样品中,探测到新形成的α-石英物相,可能与微生物的活动密切相关。
Clay minerals are widely distributed on the Earth’s surface and interactions with microorganisms are common. Whether microbes can influence the structure and phase of the depleted montmorillonite by other ways besides reduction of Fe (Ⅲ) becomes a new problem of the interaction between clay minerals and microorganisms. In this study, we selected Bacillus mucilaginosus 3027 and calcium-based montmorillonite at 35 ℃, under normal pressure conditions for interaction experiments to investigate the life of Bacillus cereus montmorillonite crystal structure. The samples were periodically sampled for the determination of pH and total protein content of the system. The effects of micro-FTIR, XANES, XRD and SEM (scanning electron microscopy) ) Mineral characterization of the final product. The experimental results show that Bacillus cereus grows in the montmorillonite mineral suspension, the metabolism of a large number of organic acids lead to lower pH value of the system, montmorillonite in the dissolution of Si, and resulting in monosilicic crystal structure of silicon oxygen on both sides Body symmetry, O-H vibration and other changes, Fe coordination octahedron symmetry decreased edge of the mineral surface curling phenomenon. In the mineral samples after the microbial action, it is probable that the newly formed α-quartz phase is closely related to the activity of microorganisms.