Characterisation of efficient denitrifying bacteria strains isolated from activated sludge by 16S-rDNA analysis

In order to investigate the diversity of the most efficient denitrifying ba cterial species in activated sludge more than 1500 bacterial strains were i solated from five different municipal wastewater treatment plants. The 24 m ost efficient denitrifying bacteria strains were selected and submitted for partial 16S rRNA analyses. Result indicated that five strains were members of the Rhodobacter group, 16 of Rubrivivax subgroup, one of Pseudomonas su bgroup and two unidentified though showing high similarity to certain membe rs of the Brucella assemblage. This indicates efficient denitrifying bacter ial strains in activated sludge are members of a restricted number of bacte rial taxa dominated by Rubrivivax subgroup. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.