The amplicons of bacterial 16S rRNA  gene from the sample W1
With the paired primers sets as the format "Adaptor-key for pyrosequencing recognition-barcodes-primer sequences": B-27F ccatctcatccctgcgtgtctccgac-TCAG-XXXXXXXXXX-GAGTTTGATCNTGGCTCAG  B-519R cctatcccctgtgtgccttggcagtc-TCAG-GTNTTACNGCGGCKGCTG