Effect of thermophilic bacteria on the siliceous deposition and phylogenetic analysis of the bacterial diversity in silica scale

Fumio Inagaki, Ryoichi Kawatsu, Yoshinobu Motomura, Katsumi Doi, Eiji Izawa, Seiya Ogata

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Silica scale, one of the major problems for geothermal power development, was formed on the copper test plates in geothermal hot water (85 ± 2°C, pH 7.2). Numerous bacterial shaped structures were observed and mixed bacterial population of genomic DNA was stably extracted from the silica scale. The amount of silica scale and extracted DNA increased exponentially with the time of incubation in the geothermal hot water. The molecular phyogenetic survey of extremely thermophilic bacterial diversities in silica scale was carried out by using the PCR-mediated small subunit rRNA gene (rDNA) sequencing. The community was composed mainly of three phylogenetic types in domain Bacteria. Cluster I was affiliated with the Aquificales and cluster II was closely related to the genus Thermus. Cluster III was homologus with Gram-positive anaerobic thermophilic bacteria. These bacterial communities may possibly contribute to the rapid aggregation of silica.

Original languageEnglish
Pages (from-to)309-316
Number of pages8
JournalJournal of the Faculty of Agriculture, Kyushu University
Issue number3-4
Publication statusPublished - Feb 1 2000


All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Agronomy and Crop Science

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