PHYLOGENETIC ASSESSMENT OF 5 FILAMENTOUS BACTERIA ISOLATED FROM BULKING ACTIVATED SLUDGES

Nearly complete 16S ribosomal RNA (rRNA) sequences were determined for fully characterised axenic strains of Thiothrix, Eikelboom type O21N, and Eikelboom type 1701 originally isolated from bulking activated sl udges. Thiothrix strains formed a monophyletic group (100% bootstrap s upport) with previously described Thiothrix nivea strain JP2 and Thiot hrix ramosa. Eikelboom type O21N strain AP3 revealed a sufficiently st rong relationship to the Thiothrix group to suggest a common ancestry for the two organisms although it was not possible to designate type 0 21N as a species of Thiothrix. Eikelboom type 1701 contained within it s sequence the target sequence of an oligonucleotide probe for the det ection of Sphaerotilus natans. (C) 1998 IAWQ. Published by Elsevier Sc ience Ltd.