16S RNA
The primers used for the amplification of 16S rRNA genes were 28F (5-GAG TTT GAT CNT GGC TCA G-3) and 519R (5-GWA TTA CCG CGG CKG CTG-3) allowing the recovery of short fragments of approximately 400 bp in the 16S rRNA gene that included the V1-V3 hypervariable regions