MiSeq of lab enrichment
DNA extraction was performed using the Qiagen PowerSoil Kit, using the manufacturers protocol. Extracted total DNA was amplified for the V4/V5 region of the 16S rDNA gene and sequencing was performed on an Illumina MiSeq sequencer. Dual indexed barcode adapters were added to the ends of the 16S rDNA amplicons by limited cycle PCR. Sequencing libraries were validated by automated electrophoresis using Agilent Tapestation 4150 and quantified by Thermo-Fisher Scientific Qubit and Applied Biosystem 7500 Fast real-time PCR. DNA libraries were multiplexed and loaded on an Illumina MiSeq instrument according to manufacturer's protocol. Base calling was conducted by the MiSeq Control Software on the MiSeq instrument.