Figure 1. Proportion of affiliated OTUs in the biofilm cultures.

(A) Bacterial composition of OB and the IO biofilm cultures was determined by sequencing the V6–V7–V8 variable regions of the 16S rRNA gene by Illumina, whereas the other samples were determined by sequencing the V1–V2–V3 variable regions by pyrosequencing. (B) Principal component analysis of the bacterial profiles of the biofilm cultures and the OB listed in Table 2.