Community analysis of a denitrifying reactor treating landfill leachate

The bacterial community of a denitrifying reactor from a system for landfill leachate decontamination was studied applying cultivation methods, denitrifying activity measurements and characterisation of community 16S rDNA. The sludge presented a high denitrifying activity but a relatively low number of denitrifying bacteria as determined by most probable number. Over 50degreesC, of the sequences retrieved in the molecular analysis were related to genera with the capacity to denitrify in the alpha- and P-betasubdivisions of the Proteobacteria. Fifteen percent of the DNAs were related to not yet cultured organisms belonging to the green non-sulphur phylum. High similarity values between sequences from isolates and clones were observed. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.