Monitoring the impact of bioaugmentation on the start up of biological phosphorus removal in a laboratory scale activated sludge ecosystem.
The acclimatisation of activated sludge to enhanced biological phosphorus removal (EBPR) conditions requires a period of about 40-100 days but its output remains hazardous. The impact of bioaugmentation on the start-up of a laboratory scale EBPR sequencing batch reactor was evaluated by process parameters measurement and microbial community dynamics monitoring using 16S rDNA targeted polymerase chain reaction-single strand conformation polymorphism electrophoresis (PCR-SSCP). Bioaugmentation: (1) speeded up the installation of good and stable EBPR in the bioaugmented reactor by about 15 days; (2) correlated with the transient enrichment of the sludge in the added microbial populations; and (3) favoured the long-term enrichment of the sludge in the phosphorus-accumulating organism (PAO) Candidatus Accumulibacter phosphatis. However, despite a lag time period, the control non-bioaugmented reactor ended up with comparable reactor parameters and microbial community evolution, suggesting that the same PAO populations were already present from the beginning in the original non-P-accumulating seed sludge. The potential of a true installation of the added microbial populations within the bioaugmented reactor compared to their substitution by indigenous similar populations is discussed. Competition between PAOs and the antagonistic glycogen accumulating organism Candidatus Competibacter phosphatis is also highlighted during EBPR start-up.
Dabert
Patrick
P
Laboratoire de Biotechnologie de l'Environnement, Institut National de la Recherche Agronomique, Avenue des Etangs, 11100 Narbonne, France. dabert@ensam.inra.fr
Delgenès
Jean-Philippe
JP
Godon
Jean-Jacques
JJ
D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D001709:Biotechnology; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D017753:Ecosystem; D019143:Evolution, Molecular; D010758:Phosphorus / Q000302:isolation & purification* / Q000378:metabolism; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012722:Sewage / Q000382:microbiology*
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012722:Sewage; D010758:Phosphorus