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:Synthetic wastewater
DNRA system:Continuous stirred-tank reactor
reactor:Chemostat culture: Double-jacket glass bioreactor
Medium:Suspended sludge growth
Culture taken from:Activated sludge
Microorganism cultured:Denitrifying and DNRA bacteria
Respiration:Anaerobic
Electron donor:Acetate
Electron acceptor:Nitrate
PH:7
Temperature:20°C
HRT:nan
NO3–N Influent conc(mg/L):23.5 mmol
NH4–N accumulation (mg/L/d):10
NO2–N removal rate (mg/L/d):3.7
NH4–N Accumulation rate (mg N/L/d):0.926
NH4–N Effluent (mg N/L):
NO2–N Effluent (mg N/L):
NO3-N Effluent (mg N/L):
NH4–N removal rate mg/L/d:
NO2–N removal rate mg/L/d:3.7
NO3-N removal rate mg/L/d:
TN Removal rate (mg N/L/d):
Authors:van den Berg et al., 2016
Title:DNRA and Denitrification Coexist over a Broad Range of Acetate/N-NO3? Ratios, in a Chemostat Enrichment Culture
Pubmed link:Link
Full research link:Link
Abstract:Denitrification and dissimilatory nitrate reduction to ammonium (DNRA) compete for nitrate in natural and engineered environments. A known important factor in this microbial competition is the ratio of available electron donor and elector acceptor, here expressed as Ac/N ratio (acetate/nitrate-nitrogen). We studied the impact of the Ac/N ratio on the nitrate reduction pathways in chemostat enrichment cultures, grown on acetate mineral medium. Stepwise, conditions were changed from nitrate limitation to nitrate excess in the system by applying a variable Ac/N ratio in the feed. We observed a clear correlation between Ac/N ratio and DNRA activity and the DNRA population in our reactor. The DNRA bacteria dominated under nitrate limiting conditions in the reactor and were outcompeted by denitrifiers under limitation of acetate. Interestingly, in a broad range of Ac/N ratios a dual limitation of acetate and nitrate occurred with co-occurrence of DNRA bacteria and denitrifiers. To explain these observations, the system was described using a kinetic model. The model illustrates that the Ac/N effect and concomitant broad dual limitation range related to the difference in stoichiometry between both processes, as well as the differences in electron donor and acceptor affinities. Population analysis showed that the presumed DRNA-performing bacteria were the same under nitrate limitation and under dual limiting conditions, whereas the presumed denitrifying population changed under single and dual limitation conditions.