Time course of dechlorination of Aroclor 1260 at various stages of the enrichment process. S3 is the third transfer on autoclaved sediment; SF1, SF2, SF3, SF4, SF5, and SF8 are the first, second, third, fourth, fifth, and eighth transfers without sediment, respectively. The Aroclor 1260 concentration was 5 μg/ml for SF1 to SF4 and 50 μg/ml for SF5 and SF8. For the S3 cultures, the sediment-associated Aroclor 1260 had been partially dechlorinated in situ. The concentration was approximately 45 μg/g (dry weight). Most data are averages for three replicates; for SF4 the data for three individual samples (SF4-A, SF4-B, and SF4-C) are shown. SF4-B showed minimal dechlorination by day 70 and was reinoculated from SF4-A and SF4-C on day 75 (indicated by an arrow). The error bars indicate the standard deviations of the means.