CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Denitrifier community composition along nitrate gradient in Suquía River bed-sediment
Autor/es:
REYNA LUCIANA; WUNDERLIN DANIEL; GENTI-RAIMONDI SUSANA
Lugar:
Mar del Plata
Reunión:
Congreso; XLIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.; 2007
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular
Resumen:
To understand the composition and structure of denitrifying communities along nitrate gradient (from 2 to 22 mg/L) in the Suquía River, the molecular diversity of narG gene from sediments obtained at seven stations was examined. The narG gene encoding the membrane bound nitrate reductase was selected as a functional marker for the nitrate-reducing community. The composition was analyzed using RFLP of narG, together with cloning and sequencing. In addition, a fingerprint of the total bacterial community was assessed by RISA. The results show different narG RFLP patterns in each community site. Two libraries of the DNA samples of the most distant sites were constructed. The clones were subjected to RFLP analysis and grouped. Nine and 20 different sequences from each libraries were obtained with all narG clones exhibiting between 62-90 % identity at the amino acid level to those of cultivated denitrifiers and other environmental clones in the database. NarG sequences clustered into three major groups, supported by phylogenetic analyses and, all sequences amplified from environmental DNA clustered in the Gram-negative group. The results indicate that some populations are indeed distinct, although further sequencing would be required to fully characterize the highly diverse denitrifying communities at these sites.