Period 1 cDNA (Bacteria)
Amplicon pyrosequencing of cDNA biofilm extract was done using 454 GS-FLX Plus system by an external company (Macrogen Inc., Seoul, South Korea). Gene fragments of bacterial 16S rRNA were amplified using universal bacterial primers (27F-GAGTTTGATCMTGGCTCAG and 518R-WTTACCGCGGCTGCTGG). Different barcodes were used to allow demultiplexing of sequences on a per sample basis.