梭菌SN-1菌株参与下形成的碳酸盐矿物组合及其主要矿物成分的动态变化

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(Clostridiumsp.)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。

The temporal changes of carbonate mineral assemblages formed by Clostridium sp. SN-1 strain and their main mineral composition

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 calcite →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.