Comparison of microbial communities based on 16S rRNA gene sequencing. Relative abundance of bacterial phyla (class for Proteobacteria) from DNA extracted from a) sample A, b) sample B and c) sample C using the PowerBiofilm (P), QuickGene (Q) and Maxwell (M) extraction methods. Unclassified sequences and phyla (or class for Proteobacteria) with membership < 1% of total sequences were pooled into the classification labeled "Other". d) Non-metric multidimensional scaling (NMDS) plot based on θ
distances between libraries extracted using the PowerBiofilm (purple), QuickGene (green) and Maxwell (black) methods from Sample A (squares), B (triangles) and C (circles). AMOVA: p < 0.001.