"Sequencing was performed on Illumina MiSeq platform with the           bacterial primers Ba27f/357r. PCR conditions: 98°C for 5 min; 98°C for 10s / 60°C for 30s           / 72°C for 30s (27 cycles); 72°C for 5 min. PCR reaction (total 25 ul): 1? NEBNext           High-Fidelity PCR Master Mix, 0.2 uM of each primer, 40 pg-ul-1 DNA template. Sample           purification: NucleoSpin Gel and PCR Clean-up kit (Macherey Nagel). Indexing PCR           conditions: 95°C for 3 min; 95°C for 30s / 55°C for 30s / 72°C for 30s (8 cycles); 72°C           for 5 min. PCR reaction (total 25 ul): Nextera XT Index Kit v2 Set B, 1x NEBNext           High-Fidelity PCR Master Mix, 400 pg-ul-1 DNA. Sample purification: band excision from           agarose gel and Gel and PCR Cleanup Kit (Macherey Nagel). Sample pool: 4           nM."