INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
MICROBIAL ECOLOGY OF AMMONIA-OXIDIZING BACTERIA IN AN ACTIVATED SLUDGE WITH UNSTABLE NITRIFICATION
Autor/es:
FIGUEROLA, EVA L. M.; ERIJMAN L.
Lugar:
Va. Carlos Paz, Córdoba, Argentina
Reunión:
Congreso; XLIV reunión anual- SAIB; 2008
Institución organizadora:
Sociedad argentina de investigación en bioquímica y biología molecular
Resumen:
Ammonia removal via nitrification is an important service provided by many wastewater treatment plants. It is a two-step process, usually rate-limited by the oxidation of ammonia to nitrite performed by ammonia-oxidizing bacteria (AOB). We have investigated this process during a period of full nitrification in a full-scale activated sludge from an oil refinery, which receives a high load of free ammonia, hydrocarbons and phenol and suffers from repeated periods of nitrification failure. A clone library of ammonia monooxygenase (amoA) gene was constructed. A total of 110 clones were divided into two OTUs separated by a genetic distance of 0.06. Dominant OTU was related to N. europaea, whereas a minor OTU was affiliated with the N. nitrosa linage. Novel primer sets were designed for quantification of amoA gene of the two detected taxons by real time PCR. The proportion of cells belonging to both OTUs was estimated as 0.6% and 0.06% of total bacteria. Similar abundance of the dominant taxon was obtained using a specific 16S rRNA-based assay. According to these results, AOB cell numbers are approximately three fold lower than the values predicted by current theoretical models. We propose that AOB adapted to perform under harsh conditions have very low yield, providing one possible explanation for why nitrification is unstable in the presence of toxic compounds such as phenol.