Ammonium assimilation: An important accessory during aerobic denitrification of Pseudomonas stutzeri T13

The effects of culture conditions on a newly isolated Pseudomonas stutzeri KTB's ability to simultaneously perform heterotrophic nitrification and aerobic denitrification were investigated to determine its potential of application in nitrogen removal from wastewater. The results from experiments in the presence of 10 mmol/L of ammonium were as follows: succinate was the preferred carbon source, and the optimum C/N ratio, temperature, and initial pH were 10, 30 °C, and 7–8, respectively. Nitrogen removal took place not only in the logarithmic phase but also in the stationary phase. Under the optimum conditions, the nitrogen removal rate increased as the ammonium concentration elevated, until it was as high as 60 mmol/L. Meanwhile, the maximum specific growth rate decreased. The highest nitrogen removal rate of 0.977 mmol/L/h was observed at 60 mmol/L of ammonium and the maximum removal ratio of 85.6% at 40 mmol/L when the bacterial treatment for 48 h was completed. The strain was vulnerable to even higher ammonium loads. When incubated in anaerobically digested hennery wastewater containing 43.85 mmol/L of ammonium and 2.32 mmol/L of nitrate, the removal ratio and rate reached 82.4% and 0.397 mmol/L/h, respectively. The strain might be a great candidate for ammonium removal from wastewater.

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Characterisation of Pseudomonas stutzeri T13 for aerobic denitrification: Stoichiometry and reaction kinetics

The Science of The Total Environment ◽

10.1016/j.scitotenv.2019.135181 ◽

2020 ◽

Vol 717 ◽

pp. 135181 ◽

Cited By ~ 3

Author(s):

Liang Feng ◽

Jixian Yang ◽

Fang Ma ◽

Shanshan Pi ◽

Lulu Xing ◽

...

Keyword(s):

Reaction Kinetics ◽

Pseudomonas Stutzeri ◽

Aerobic Denitrification

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Potential of Aerobic Denitrification by Pseudomonas stutzeri TR2 To Reduce Nitrous Oxide Emissions from Wastewater Treatment Plants

Applied and Environmental Microbiology ◽

10.1128/aem.01983-09 ◽

2010 ◽

Vol 76 (14) ◽

pp. 4619-4625 ◽

Cited By ~ 84

Author(s):

Morio Miyahara ◽

Sang-Wan Kim ◽

Shinya Fushinobu ◽

Koki Takaki ◽

Takeshi Yamada ◽

...

Keyword(s):

Nitrous Oxide ◽

Bacterial Species ◽

Pseudomonas Stutzeri ◽

Sharp Contrast ◽

Nitrous Oxide Emissions ◽

Aerobic Denitrification ◽

Piggery Wastewater ◽

Lower Growth ◽

Aerobic Conditions ◽

Denitrification Activity

ABSTRACT In contrast to most denitrifiers studied so far, Pseudomonas stutzeri TR2 produces low levels of nitrous oxide (N2O) even under aerobic conditions. We compared the denitrification activity of strain TR2 with those of various denitrifiers in an artificial medium that was derived from piggery wastewater. Strain TR2 exhibited strong denitrification activity and produced little N2O under all conditions tested. Its growth rate under denitrifying conditions was near comparable to that under aerobic conditions, showing a sharp contrast to the lower growth rates of other denitrifiers under denitrifying conditions. Strain TR2 was tolerant to toxic nitrite, even utilizing it as a good denitrification substrate. When both nitrite and N2O were present, strain TR2 reduced N2O in preference to nitrite as the denitrification substrate. This bacterial strain was readily able to adapt to denitrifying conditions by expressing the denitrification genes for cytochrome cd 1 nitrite reductase (NiR) (nirS) and nitrous oxide reductase (NoS) (nosZ). Interestingly, nosZ was constitutively expressed even under nondenitrifying, aerobic conditions, consistent with our finding that strain TR2 preferred N2O to nitrite. These properties of strain TR2 concerning denitrification are in sharp contrast to those of well-characterized denitrifiers. These results demonstrate that some bacterial species, such as strain TR2, have adopted a strategy for survival by preferring denitrification to oxygen respiration. The bacterium was also shown to contain the potential to reduce N2O emissions when applied to sewage disposal fields.

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