Biological Nitrogen Removal Database
A manually curated data resource for microbial nitrogen removal
Biological Nitrogen Removal Database
A manually curated data resource for microbial nitrogen removal
Influent:Membrane bioreactor (MBR)
Anammox system:Heterotrophic nitrification
Anammox reactor:Membrane bioreactor (MBR)
Medium:Suspension
Culture taken from:Activated sludge
Microorganism cultured:Alcaligenes faecalis strain NR
Respiration:Aerobic
Electron donor:Ammonium chloride
Electron acceptor:Oxygen, Sodium nitrite
PH:7.1–7.4
Ammonia removal rate:26.9 mg L-1 h-1
Nitrate removal rate:nan
Ammonia Removal efficiency (%):nan
Nitrate Removal efficiency (%):nan
Total Nitrogen Removal (%):0.151
Carbon Source:Citrate
Final products:Nitrogen, Nitrous oxide, Nitrite, Nitric oxide
Major findings:A. faecalis NR shows a capability of heterotrophic nitrification and N2O and N2 production as well under aerobic conditions. Study suggests that there are two distinct metabolic pathways for ammonium oxidation might exist in A. faecalis NR. One is heterotrophic nitrification by oxidizing ammonium to nitrite and nitrate. The other is oxidizing ammonium to nitrogenous gas directly via hydroxylamine. This novel nitrogen metabolic pathway is of great significance to nitrogen cycle and provides a potential to simplify the biological nitrogen removal process.
Authors:Zhao et al., 2012
Title:N2O and N2 production during heterotrophic nitrification by Alcaligenes faecalis strain NR
Pubmed link:Link
Full research link:Link
Abstract:A heterotrophic nitrifier, strain NR, was isolated from a membrane bioreactor. Strain NR was identified as Alcaligenes faecalis by Auto-Microbic system and 16S rRNA gene sequence analysis. A. faecalis strain NR shows a capability of heterotrophic nitrification and N(2)O and N(2) production as well under the aerobic condition. Further tests demonstrated that neither nitrite nor nitrate could be denitrified aerobically by strain NR. However, when hydroxylamine was used as the sole nitrogen source, nitrogenous gases were detected. With an enzyme assay, a 0.063 U activity of hydroxylamine oxidase was observed, while nitrate reductase and nitrite reductase were undetectable. Thus, nitrogenous gas was speculated to be produced via hydroxylamine. Therefore, two different metabolic pathways might exist in A. faecalis NR. One is heterotrophic nitrification by oxidizing ammonium to nitrite and nitrate. The other is oxidizing ammonium to nitrogenous gas directly via hydroxylamine.