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Supercritical Nitrogen Processing for the Purification of Reactive Porous Materials
Published on: May 15, 2015
Acetylene reduction (nitrogen fixation) by enterobacteriaceae isolated from paper mill process waters
1Institutet för Vatten-och Luftvårdsforskning, S-100 31 Stockholm, Sweden.
Applied and Environmental Microbiology
|August 1, 1976
Summary
Paper mill bacteria, including Klebsiella pneumoniae and Escherichia coli, exhibit significant nitrogen-fixing activity. These Enterobacteriaceae demonstrate tolerance to oxygen, suggesting a role in natural nitrogen cycling.
Area of Science:
- Microbiology
- Environmental Science
- Biochemistry
Background:
- Enterobacteriaceae are common bacteria found in various environments.
- Nitrogen fixation is a crucial process for nutrient cycling in ecosystems.
Purpose of the Study:
- To isolate and characterize nitrogen-fixing Enterobacteriaceae from paper mill environments.
- To assess the nitrogen-fixing potential and oxygen tolerance of these bacteria.
Main Methods:
- Isolation of bacteria using selective media (galactitol).
- Characterization of acetylene-reducing (nitrogen-fixing) activity under varying conditions (anaerobic, aerobic, oxygen exposure).
- Assay of nitrogenase synthesis and activity in response to amino acids and ammonium.
Main Results:
- Over 130 Enterobacteriaceae strains were isolated, with high nitrogen-fixing activity observed in species like Klebsiella pneumoniae and Escherichia coli.
- Nitrogenase synthesis was generally not repressed by common amino acids or Casamino Acids.
- Bacterial strains showed tolerance to oxygen inactivation of nitrogen-fixing activity, with partial reversibility observed.
- Nitrogenase synthesis occurred in aerobic cultures, albeit at lower protein concentrations than under anaerobic conditions.
Conclusions:
- Enterobacteriaceae from paper mill waters possess significant nitrogen-fixing capabilities.
- The observed oxygen tolerance suggests these bacteria can contribute to nitrogen economy in natural settings.
- Further investigation into the ecological role of these nitrogen-fixing bacteria is warranted.
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