在Mg/Ca比值为6的Lagoa vermelha改良培养基中,对分离自青海湖湖底沉积物的梭菌(Clostridium sp.)进行了为期100 d的碳酸盐矿物培养实验,同时还完成了一组无菌对照实验.利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)分别对矿物成分和形态进行了测定和观察.实验结果表明:细菌培养实验的沉淀物数量始终多于无菌对照实验；在梭菌SN-1菌株作用下形成的碳酸盐矿物组合的变化趋势是方解石→方解石+单水碳钙石→单水碳钙石+方解石→单水碳钙石,而无菌对照实验产物中矿物的演化方向是单水碳钙石+方解石→方解石+单水碳钙石；在综合分析SEM和XRD观测结果的基础上,推测哑铃状矿物可能是高镁方解石,而球状矿物可能是单水碳钙石.%Culture experiments of carbonate mineral using Lagoa Vermelha improved medium with 6:1 molar ratio of Mg/Ca within 100 days were conducted under the mediation of Clostridium sp. (SN-1 strain) isolated from sediments in the Qinghai Lake. At the same time, aseptic experiments were carried out as the control. Mineral species and morphologies were determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results showed that: ① The quantities of sediments in bacterial culture experiments were always more than those in the control ones. ② The change trend of carbonate mineral assemblages formed in Clostridium sp. SN-1 strain culture was calcite → calcite and monohydrocalcite → monohydrocalcite and cal-cite → monohydrocalcite, while in the control experiments the change trend was monohydrocalcite and calcite→ calcite and monohydrocalcite; ③ Based on comprehensive analysis of SEM and XRD, the authors considered that dumbbell-shaped minerals might be high-magnesium calcite, while spherical minerals might be monohydrocalcite.
展开▼
