Bioaugmentation of a wastewater bioreactor system with the nitrous oxide-reducing denitrifier Pseudomonas stutzeri strain TR2

Wakako Ohtsubo, Morio Miyahara, Sang Wan Kim, Takeshi Yamada, Masaki Matsuoka, Akira Watanabe, Shinya Fushinobu, Takayoshi Wakagi, Hirofumi Shoun, Keisuke Miyauchi, Ginro Endo

Research output: Contribution to journalArticlepeer-review


In bioaugmentation technology, survival of inoculant in the treatment system is prerequisite but remains to be a crucial hurdle. In this study, we bioaugmented the denitrification tank of a piggery wastewater treatment system with the denitrifying bacterium Pseudomonas stutzeri strain TR2 in two pilot-scale experiments, with the aim of reducing nitrous oxide (N 2O), a gas of environmental concern. In the laboratory, strain TR2 grew well and survived with high concentrations of nitrite (5-10 mM) at a wide range of temperatures (28-40°C). In the first augmentation of the pilotscale experiment, strain TR2 inoculated into the denitrification tank with conditions (30°C, ∼0.1 mM nitrite) survived only 2-5 days. In contrast, in the second augmentation with conditions determined to be favorable for the growth of the bacterium in the laboratory (40-45°C, 2-5 mM nitrite), strain TR2 survived longer than 32 days. During the time when the presence of strain TR2 was confirmed by quantitative real-time PCR, N2O emission was maintained at a low level even under nitrite-accumulating conditions in the denitrification and nitrification tanks, which provided indirect evidence that strain TR2 can reduce N2O in the pilot-scale system. Our results documented the effective application of growth conditions favorable for strain TR2 determined in the laboratory to maintain growth and performance of this strain in the pilot-scale reactor system and the decrease of N2O emission as the consequence.

Original languageEnglish
Pages (from-to)37-42
Number of pages6
JournalSeibutsu-kogaku Kaishi
Issue number1
Publication statusPublished - 2013 Mar 1
Externally publishedYes


  • Bioaugmentation
  • Denitrification
  • Inoculant survival
  • Quantitative real-time PCR
  • Wastewater treatment

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Applied Microbiology and Biotechnology


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