Distribution of Nitrosomonas europaea and Nitrobacter winogradskyi in an autotrophic nitrifying biofilm reactor as depicted by molecular analyses and mathematical modelling.
The autotrophic two-species biofilm from the packed bed reactor of a life-support system, containing Nitrosomonas europaea ATCC 19718 and Nitrobacter winogradskyi ATCC 25391, was analysed after 4.8 years of continuous operation performing complete nitrification. Real-time quantitative polymerase chain reaction (Q-PCR) was used to quantify N. europaea and N. winogradskyi along the vertical axis of the reactor, revealing a spatial segregation of N. europaea and N. winogradskyi. The main parameters influencing the spatial segregation of both nitrifiers along the bed were assessed through a multi-species one-dimensional biofilm model generated with AQUASIM software. The factor that contributed the most to this distribution profile was a small deviation from the flow pattern of a perfectly mixed tank towards plug-flow. The results indicate that the model can estimate the impact of specific biofilm parameters and predict the nitrification efficiency and population dynamics of a multispecies biofilm.
Montràs
Anna
A
Department of Chemical Engineering, Universitat Autònoma de Barcelona, ETSE, Ed. Q, 08193 Barcelona, Spain. anna.montras@uab.cat
Pycke
Benny
B
Boon
Nico
N
Gòdia
Francesc
F
Mergeay
Max
M
Hendrickx
Larissa
L
Pérez
Julio
J
D001483:Base Sequence; D018441:Biofilms; D019149:Bioreactors; D017931:DNA Primers; D017404:In Situ Hybridization, Fluorescence; D008962:Models, Theoretical; D009576:Nitrobacter / Q000235:genetics / Q000302:isolation & purification*; D009606:Nitrosomonas / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics
D017931:DNA Primers; D012336:RNA, Ribosomal, 16S