Microbial community analysis in the denitrification process of saline-wastewater by denaturing gradient gel electrophoresis of PCR-amplified 16S rDNA and the cultivation method

Sachiko Yoshie, Naohiro Noda, Tomoko Miyano, Satoshi Tsuneda, Akira Hirata, Yuhei Inamori

Research output: Contribution to journalArticle

39 Citations (Scopus)


The metallurgic wastewater generated from the processes of recovering precious metals from industrial wastes contains high concentrations of nitrogen compounds and salts. Biological nitrogen removal from this wastewater was attempted using a circulating bioreactor system equipped with an anaerobic packed bed or an anaerobic fluidized bed. The denitrification capability of the system with the anaerobic packed bed was more stable than that of the system with the anaerobic fluidized bed. The NOx removal rate of the anaerobic packed bed was as high as 97%. Microbial community analysis by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA (rDNA) fragments and the cultivation method revealed that the community diversity varied in accordance with wastewater composition such as the level of salinity and so on. Phylogenetic analysis suggested that the taxonomic affiliation of the dominant species in the anaerobic reactors was to the γ-Proteobacteria including Halomonadaceae species. The PCR-DGGE method as a non-cultivation method was found to be a powerful tool for analysis of the microbial community, because the cultivation method could detect only a fraction of the microbial species present in these systems. The genetic diversity of the isolated bacteria belonging to the γ-Proteobacteria which reduced both nitrate and nitrite in the anaerobic packed bed was higher than that of the bacteria in the anaerobic fluidized bed. This suggested that a genetically diverse microbial community stabilized the denitrifying performance in the anaerobic packed bed.

Original languageEnglish
Pages (from-to)346-353
Number of pages8
JournalJournal of Bioscience and Bioengineering
Issue number4
Publication statusPublished - 2001 Jan 1



  • Denitrification
  • Metallurgic wastewater
  • Microbial community
  • Saline

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology

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