Enhanced selection of an anaerobic pentachlorophenol-degrading consortium

A rapid enrichment approach based on a pentachlorophenol (PCP) feeding stra tegy which linked the PCP loading rate to methane production was applied to an upflow anaerobic sludge bed reactor inoculated with anaerobic sludge. D ue to this strategy, over a 140-day experimental period the PCP volumetric load increased from 2 to 65 mg L-R(-1) day-(1) with a near zero effluent co ncentration of PCP. Dechlorination dynamics featured sequential appearance of 3,4,5-chlorophenol, 3,5-chlorophenol, and 3-chlorophenol in the reactor effluent. Profiling of the reactor population by denaturing gradient gel el ectrophoresis (DGGE) revealed a correlation between the appearance of dechl orination intermediates and bands on the DGGE profile. Nucleotide sequencin g of newly detected 16S rDNA fragments suggested the proliferation of Clost ridium and Syntrophobacter/Syntrophomonas spp. in the reactor during PCP de gradation. Published by John Wiley & Sons, Inc.