Metagenomic sequencing of effluent sample: 2_1
Metagenomic extractions on all samples were performed using the MoBio PowerSoil DNA Isolation Kit (Qiagen, Venlo, Netherlands), as per the manufacturers protocol, and including a beadbeating step of two 40 second cycles at 6 m/s in lysing matrix E. 12.5 ng of naked Thermus thermophilus DNA (reference strain HB27, Collection number ATCC BAA-163, ordered from DSMZ, Germany) was added to each sample in the PowerBead tube at the start of the experiment, prior to the addition of Solution C1 of the DNA Isolation Kit. The rationale for this was to enable subsequent normalisation to the number of T. thermophilus genomes sequenced to adjust for varying amounts of sample input, and extraction bias.