INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Factors that drive bacterial community composition in activated sludge
Autor/es:
FEDERICO IBARBALZ; EVA L. M. FIGUEROLA; LEONARDO ERIJMAN
Lugar:
Mar del Plata
Reunión:
Congreso; Congreso Argentino de Microbiología General; 2012
Institución organizadora:
Sociedad Argentina de Microbiología General
Resumen:
The process of activated sludge (AS) is the most widely used method for
treatment of wastewater worldwide. It relies on the aerobic degradation of
organic matter by a highly dynamic mixture of microorganisms, which are
subsequently separated by gravity settling owing to their ability to
aggregate into flocs. The aim of the work was to investigate the factors
that drive the bacterial community composition in AS. Based on previous
surveys of bacterial communities in AS and on the concept of ecological
coherence of high taxonomic ranks (meaning that the members of a
taxon share functional traits that distinguish them from members of other
taxa), we hypothesized that there would be a consistent set of bacterial
taxa common to AS plants, regardless the origin of the wastewater and
the plant configuration.
We applied 454 pyrosequencing of 16S rRNA genes to evaluate bacterial
communities in several full-scale biological wastewater treatment plants
(WWTP) sampled at different times, including systems treating
wastewater from different industries and domestic wastewater and labscale
reactors fed with synthetic sewage. Cluster analysis at the 5% level
revealed a clear separation by WWTP, indicating the existence of
distinctive core communities associated to each treatment plant. The
influence of environmental and process parameters on the bacterial
community structure was evaluated using canonical correspondence
analysis (CCA). The first ordination axis correlated with pH. The second
canonical axis correlated to the BOD to COD ratio (a proxy of the
biodegradability of the wastewater) and Dissolved Oxygen (DO).
Firmicutes and Lentisphaeras were associated to high pH, Acidobacteria
and Chlorobi to high DO. As regards with sites, separation of the textile WWTP was strongly influenced by pH, while the whey WWTP showed to be influenced by the BOD to COD ratio.
In conclusion, the bacterial community structure of AS plants is unique to each system. The taxa distribution is driven primarily by the wastewater composition, pH and DO.