Impact of non-ionic surfactant on the long-term development of lab-scale-activated sludge bacterial communities.
The development of bacterial communities in replicate lab-scale-activated sludge reactors degrading a non-ionic surfactant was evaluated by statistical analysis of denaturing gradient gel electrophoresis (DGGE) fingerprints. Four sequential batch reactors were fed with synthetic sewage, two of which received, in addition, 0.01% of nonylphenol ethoxylates (NPE). The dynamic character of bacterial community structure was confirmed by the differences in species composition among replicate reactors. Measurement of similarities between reactors was obtained by pairwise similarity analysis using the Bray Curtis coefficient. The group of NPE-amended reactors exhibited the highest similarity values (Sjk=0.53+/-0.03), indicating that the bacterial community structure of NPE-amended reactors was better replicated than control reactors (Sjk=0.36+/-0.04). Replicate NPE-amended reactors taken at different times of operation clustered together, whereas analogous relations within the control reactor cluster were not observed. The DGGE pattern of isolates grown in conditioned media prepared with media taken at the end of the aeration cycle grouped separately from other conditioned and synthetic media regardless of the carbon source amendment, suggesting that NPE degradation residuals could have a role in the shaping of the community structure.
Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Vuelta de Obligado 2490, Buenos Aires 1428, Argentina.
Mariana
M
Lozada
Laura
L
Basile
Leonardo
L
Erijman
D001419:Bacteria / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D017077:Culture Media, Conditioned; D003902:Detergents / Q000494:pharmacology*; D004586:Electrophoresis; D005026:Ethylene Glycols / Q000494:pharmacology*; D012722:Sewage / Q000382:microbiology*
D017077:Culture Media, Conditioned; D003902:Detergents; D005026:Ethylene Glycols; D012722:Sewage; C021754:terics