Microbial participation in the formation of siliceous scale from geothermal waters and scale control

微生物参与地热水硅质垢的形成及垢控制

• 批准号: 06555314
• 负责人: IZAWA Eiji
• 金额: $ 7.17万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06555314/
• 关键词: Silica scale; Geothermal power station; Geothermal water; Microbes; DNA; Sinter; 鉱物

1.Experiments of siliceous scale formation : Studies on siliceous deposits were carried out at the Otake geothermal power plant, Oita prefecture, Kyushu, Japan. Thin copper plates were immersed in the geothermal water of the aging tank, from June to December, 1994 and from September to December, 1995. Temperatures, pH and SiO2 content of the geothermal water were measured. The siliceous deposits grew cylindrically on the plate. The siliceous deposit on the plate was gently removed from the geothermal water and placed immediately in liquid nitrogen and stored at -20ﾟC until use.2.Mineralogical studies : The siliceous deposits were examined under the microscope and by X-ray diffraction analysis. The chemical composition was determined by X-ray fluorescence. Scale consists of namy mineral phases, which formed in situ, in the well head and in depth.3.Investigation of microbial participation : Numerousrod-shaped bacterial cells were observed in amorphous silica formed on the copper plate pl … More aced in geothermal hot water, under conditions of pH 7.2 and 85(]SY.+-。[)2ﾟC.(1) Bulk genomic DNA in the siliceous deposit could be stably extracted using the lysozyme and freeze-thaw method. The volume of siliceous deposit formed on one copper plate and the amount of genomic DNA extracted from siliceous deposits was exponentially increased with the time of incubation.(2) The phylogenetic diversity in these DNA extracts was investigated by cloning and sequencing of partial 16S rRNA genes obtained by PCR.The bacterial community was composed mainly of three phylogenetic types in domain Bacteria. Cluster I (8 clones) was affiliated with the Aquificales and Cluster II (15 clones) was closely related to genus Thermus. Cluster III (2 clones), the sequences of which were homologous with Gram positive anaerobic thermophilic bacteria, was also detected.4.These extremely thermophilic bacteria may contribute to the rapid aggregation of amorphous silica and can probably serve as a parameter to determine the rate formation of siliceous deposit in the process of biomineralization. Less

1.硅质垢形成实验：在日本九州大分县大竹地热发电厂进行了硅质沉积物的研究。1994年6月~ 12月和1995年9月~ 12月，将薄铜板浸入老化槽的地热水中。测定了地热水的温度、pH值和SiO2含量。硅质沉积物在板块上呈柱状生长。将板上的硅质存款轻轻地从地热水中取出，并立即置于液氮中，并在-20 ° C下储存直至使用。2.矿物学研究：在显微镜下和通过X射线衍射分析来检查硅质存款。用X射线荧光法测定了其化学组成。3.微生物参与的调查：在铜板板上形成的无定形二氧化硅中观察到大量杆状细菌细胞，这些杆状细菌细胞是由大量的细菌细胞组成的。 ...更多信息 在地热热水中，在pH7.2和85（±）SY. [)2 C. (1)用溶菌酶和冻融法可以稳定地提取硅质存款中的大量基因组DNA。随着培养时间的延长，在一个铜板上形成的硅质存款的体积和从硅质存款中提取的基因组DNA的量呈指数增加。(2)通过对16 S rRNA基因的克隆和测序，分析了这些细菌的系统发育多样性。聚类Ⅰ（8个克隆）隶属于水生目，聚类Ⅱ（15个克隆）与栖热菌属关系密切。聚类III（2个克隆）与革兰氏阳性厌氧嗜热菌序列同源。4.这些极端嗜热菌可能参与了无定形二氧化硅的快速聚集，并可能作为生物矿化过程中硅质存款形成速率的一个参数。少