The dynamics of the bacterial community compositions in the inoculum, BFHS, BFAOM, and BFR2A samples: (A) relative abundance at the phylum level, (B) relative abundance at the class level affiliated to phylum Proteobacteria. “Other” represents taxa with relative abundance less than 1% in all samples and unassigned taxa. For each biofilm sample, the DNA extracts from two biofilm grown-coupons were used for sequencing.