library_construction_protocol: "16S rRNA gene amplicon sequencing of the V1/V2 region was performed on a MiSeq platform from Illumina; for amplifications the primers S-D-Bact-0343-a-A-15 and S-D-Bact-0008-a-S-16, and NEBNext� High-Fidelity 2X PCR Master Mix were used ( PCR conditions:  50 ng of template DNA; 98 �C for 5 min, 30 cycles: 98 �C for 20 s/ 59 �C for 30 s/ 72 �C for 30 s; 72�C for 10min).  Sample purification: Gel and PCR Cleanup Kit (Macherey Nagel). Indexing PCR with primers of the Nextera� XT Index Kit v2 Set A and Set C) and  NEBNext� High-Fidelity 2X PCR Master Mix ( PCR conditions: 10 ng of template DNA;  98 �C for 30 s, eight cycles: 98 �C for 10 s/ 55 �C for 30 s/ 72 �C for 30 s; 72�C for 5min)."