Use of PCR-DGGE Based Molecular Methods to Analyse Microbial Community Diversity and Stability during the Thermophilic Stages of an ATAD Wastewater Sludge Treatment Process as an Aid to Performance Monitoring

Figure 1

Succession of bacterial communities during the ATAD process as monitored by DGGE fingerprints from DNA targets amplified by PCR from directly extracted ATAD sludge DNA. Primers targeted conserved regions of the V3–V5 and V6–V8 regions of the bacterial 16S rDNA and rpoB gene sequences. Lane 1: thickened sludge, Lane 2: Reactor 1A (after 4 hours), Lane 3: Reactor 1A (after 8 hours), Lane 4: Reactor 1A (after 16 hours), Lane 5: Reactor 2A (after 4 hours), Lane 6: Reactor 2A (after 23 hours),and Lane 7: product (biosolids after treatment). The pattern for thermophilic sludge (Reactor 2A) is illustrated by the underlying arrows. Unique bands from the thermophilic fingerprints are highlighted with (*) on the right side of the lane. The bar indicates the profile from the thermophilic stage in Reactor 2A.