NOVELTY - An isolated 16S rDNA sequence (I) indicative of the presence of an activated bacterial strain comprises: (a) any of 7 fully defined sequences of 1385-1539 bp (SEQ ID NO:1-7) or any of 15 fully defined sequences of 18-46 bp (SEQ ID NO: 16-30), all given in the specification; (b) hybridizing with the sequence of (a) under conditions of 6xSSC (1 M NaCl), 50% formamide. 1% SDS at 37degreesC, and a wash in 0.1xSSC at 60-65degreesC; (c) at least 97% sequence identity to the sequence of (a); or (d) complements of the sequences of (a), (b) or (c).    USE - The methods and compositions of the present invention are useful for molecular biology and microbiology, particularly in identifying and isolating several previously unrecognized bacteria from an industrial wastewater bioreactor.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a method for identifying an activated sludge bacterial strain, comprising extracting genomic DNA from a bacterial cell, and probing the DNA with a probe derived from any of the sequences of (1) or under suitable hybridization conditions, where the identification of a hybridizable nucleic acid fragment confirms the presence of an activated sludge bacterial strain, or amplifying the extracted DNA with at least one oligonucleotide primer corresponding to a portion of any of the sequences of (1) such that amplification products are generated, where the presence of the amplification products confirms the presence of activated sludge bacterial strain;    (2) a pyruvate degrading bacterial strain having the 16S rDNA sequence from SEQ ID NO: 1, 2, 5, 6 and 7;    (3) a acetate degrading bacterial strain having the 16S rDNA sequence from SEQ ID NO: 3 and 4;    (4) a benzoate degrading bacterial strain having the 16S rDNA sequence from SEQ ID NO: 2, 6 and 7;    (5) a denitrifying degrading bacterial strain having the 16S rDNA sequence from SEQ ID NO: 1 and 6;    (6) a method for the degradation of pyruvate, acetate or benzoate, comprising contacting the bacterial strain of (2)-(4) under suitable growth conditions with a pyruvate, acetate or benzoate whereby the pyruvate, acetate or benzoate is degraded, respectively; and    (7) a method for the reduction of nitrate, comprising contacting the bacterial strain of (5) under suitable conditions with a nitrate whereby the nitrate is reduced.