title: Activated sludge and leachate from landfills
design: DNA was extracted from activated sludge samples in 3 technical replicates using the GeneMatrix Environmental DNA/RNA Extraction kit (Eurx, Gdask, Poland) according to the manufacturer's instructions. The quality of the obtained material was checked by electrophoresis in 1% agarose gel. In order to assess the amount of matrix supplied, measurements were also performed using a Qubit 3.0 fluorimeter (Thermo Scientific) and a dedicated Qubit High Sensitivity DNA kit reagent.The choice of primers for sequencing follows the recommendations presented in the literature.