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【目的】为了探讨细菌对碳酸盐矿物种类和形态的影响。【方法】本文利用丛毛单胞菌HJ-1菌株进行了持续50 d的培养实验。在实验过程中,对细菌数量、沉淀物重量、培养液中Ca2+和Mg2+浓度等进行了动态监测。利用扫描电子显微镜对矿物形态进行了观察,并利用X-射线衍射仪对矿物成分进行测定。【结果】丛毛单胞菌HJ-1菌株具有显著的诱导碳酸盐矿物沉淀的能力,碳酸盐矿物的重量随着培养时间的延长而逐渐增加。X-射线衍射结果表明,形成的碳酸盐沉淀主要由文石和高镁方解石组成,其中文石的最高含量达86%。上述矿物在形态上复杂多样,主要有杆状、柱状、哑铃形、球状和板状以及不规则状和鳞片状集合体。【结论】通常,在Mg/Ca≤2并且有微生物参与的条件下极少形成文石。本文在Mg/Ca为2,不含碳酸根离子的培养基中培养HJ-1菌株的过程中发现了文石。作者认为,低Mg/Ca条件下文石的形成主要与HJ-1菌株分泌较多的胞外多糖有关。
【Objective】 In order to investigate the effects of bacteria on carbonate mineral species and morphology. 【Method】 The experiment was carried out for 50 days using Comamonas sp. HJ-1 strain. During the experiment, the quantity of bacteria, the weight of sediment, the concentrations of Ca2 + and Mg2 + in culture medium were dynamically monitored. Morphology was observed by scanning electron microscopy, and the mineral composition was determined by X-ray diffractometer. 【Result】 Comamonas sp. HJ-1 strain had significant ability to induce carbonate mineral precipitation. The weight of carbonate minerals increased gradually with the incubation time. X-ray diffraction results show that the carbonate precipitate formed consists mainly of aragonite and high-magnesium calcite, with the highest content of aragonite being 86%. The above-mentioned minerals are complex and diverse in morphology, mainly including rod-shaped, columnar, dumbbell-shaped, spherical and plate-shaped, and irregular and scaly aggregates. [Conclusion] Aragonites are rarely formed under conditions of Mg / Ca <2 and with the involvement of microorganisms. Aragonite was found in the culture of HJ-1 strain in a medium containing 2% Mg / Ca and without carbonate ions. The authors believe that the formation of aragonite at low Mg / Ca conditions is mainly related to the secretion of extracellular polysaccharides by HJ-1 strains.