FIG. 4.

UPGMA clustering of DGGE fingerprints of the tmoA-like PCR amplicons obtained with primer set GC-TMOA-F/TMOA-R from DNAs extracted from the aquifer materials in the mesocosms and from fresh aquifer materials at different times. Clustering was performed by using the Pearson moment-based similarity coefficient. T0, 9 January 2003; T1, 16 January 2003; T2, 30 January 2003; T3, 10 March 2003; T4, 20 May 2003. The wells of origin are indicated as described in the legend to Fig. 3. The arrow indicates the DGGE band which appeared when uncontaminated aquifer material from A0Z was placed into the wells located in the contaminated area A1.