TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Microorganism: (I) preferably in combination with an additive is useful for enhancing the dechlorination efficacy. (I) preferably comprises a sequence 98% identical to (S1) or a sequence complementary to (S1). A dechlorination efficacy-enhancing agent is preferably hydrogen, acetate, formate or fumarate.Preferred Method: (M1) further comprises subjecting the site to bioremediation treatment subsequent to the occurrence of hybridization, where the treatment include microbial dechlorination of polchlorinated biphenyls (PCBs) at the site, and the contacting of the nucleic acid sequences is carried at intervals during the bioremediation treatment to determine progress or a conclusion.Preferred Composition: In (II), PCB degradation-enhancing agent for (I) comprises a component which include hydrogen, acetate, formate and fumarate. In (III), the consortium of dechlorinatingly effective microbial species comprises dechlorinatingly effective anaerobic microbial species preferably in a mixture with dechlorinatingly effective aerobic microbial species, where a consortium of the microbial species comprises a sequence having 95% identity to (S1) and (S2). (III) further comprises at least a growth additive for microbial species in the consortium. WIDER DISCLOSURE - Also disclosed are the following:    (1) monitoring CB-containing site, comprising conducting serial observations using (M1);    (2) enrichment culture that reductively dechlorinates 3,5-dichlorobiphenyl or 3,3',4,4'-tetrachlorbiphenyl; and    (3) probes and primers designed by alignment of 16S regions from at least two PCB-dechlorinating species, and identification of primers that amplify amplicons specific for those microorganisms and capable of priming polymerase chain reaction (PCR).    SPECIFIC SEQUENCES - (I) comprises a 16S ribosomal subunit nucleic acid sequence (S1) of 1359 and 336 amino acid as given in the specification (claimed).    EXAMPLE - Sediment samples were collected with a petite Ponar grab sampler at a subsurface depth of 4 m in the Ashley River branch of Charleston Harbor (Charleston, SC, USA). Sediments had a black coloration, and a gelatinous texture. The combined contents of the sampler were transferred to 0.95 l canning jars. The jars were filled to the top and immediately sealed with dome tops and ring sealed to exclude air. A sediment-free estuarine medium (E-C1) was prepared with the exclusion of Na2S.9H2O, and was autoclaved and the final pH of the medium was set as 7. The enrichment cultures were prepared by inoculating sterile E-C1 with an active 2,3,4,5-CB para-dechlorinating culture. The congener 2,3,4,5-tetrachlorobiphenyl (CB) was solubilized in 10 mul of acetone and added to the enrichment cultures at a final concentration of 350 muM (100 ppm).    Several combinations of energy sources and antibiotics were added to cultures, yielding five enrichment conditions, each in triplicate. The energy sources in the different treatments included fumarate (10 mM) and formate (10 mM). Hydrogen was also used as a substrate by substituting 101 kPA H2CO2 (80-20 v/v) for N2CO2 in the headspace. The antibiotics added were vancomycin and ampicillin, which were dissolved in deionized water, filter sterilized and added to final concentrations of 20 mug/ml.    All cultures were incubated in the dark at 30degreesC. Polychloro biphenyls (PCBs) were analyzed according to the method of Berkaw et al.. DNA was extracted and was subjected to amplified ribosomal DNA restriction analysis (ARDRA), which involved amplification of bacterial 16S rDNA from the mixed microbial community was carried out using the universal primer set 519F (5'-CAGCA/CGCCGCGGTAATA/TC-3') and 1406R (5'-ACGGGCGGTGTGTA/GC-3'). Triplicate PCR products were combined and purified. Plasmid libraries were generated in pCR2.1 vector and screened by restriction analysis after digestion with the endonucleases HaeIII and Hha. Two representative clones from each unique restriction fragment length polymorphism (RFLP) pattern were sequenced and analyzed using comparative phylogenetic analysis.    A Qiagen Plasmid Mini Kit was used to purify plasmid DNA. The purified plasmid was used as the template for dye terminator cycle sequencing on an ABI 373 Automated sequencer. The sequence was examined for errors and edited using DNAman then checked for chimera formation using the CheckChimera program of the Ribosomal Database Project. The sequence was then submitted to the National Center for Biotechnology Information's (NCBI) Basic Local Alignment Search Tool (BLAST) and the Ribosomal Database project to determine percentage similarity with other 16S rDNA molecules. Sequences of the partial 16S rDNA of RFLP types 6, 26, 49, 181, 182, 187, 191, 194, 287, 412, 413, 414, 415, 419, 420, 421, 423, 426, 427 and 428 were submitted to GenBank under accession no. AF295740-AF295760 respectively.    RFLP type I had been previously submitted to GenBank with accession number AF058000. Anaerobic dechlorination rates monitored over 73 days in the enrichment cultures were highly reproducible for replicates of each culture treatment. Using ARDRA analysis it was determined that the formate-based culture contained the highest diversity of RFLP types and cultures that were enriched with fumarate or hydrogen had lower levels of RFLP diversity.