Fig. 3

Principal Coordinates Analysis (PCoA) based on Bray–Curtis distance from bacterial 16S rRNA gene sequences. Samples were simply represented by the numbers showing the sampling dates. Triangles: samples from SHARON reactor. Circles: samples from ANAMMOX reactor. Blue: samples obtained with influent load stepwise increased from NH₄⁺–N 50 mg/L/NO₂⁻–N 55 mg/L to NH₄⁺–N 272.7 mg/L/300 mg/L (days 1–160); Bottle-green: samples obtained with influent load NH₄⁺–N 300 mg/L/NO₂⁻–N 330 mg/L (days 161–187); Orange: samples obtained with influent load NH₄⁺–N 272.7 mg/L/NO₂⁻–N 300 mg/L (days 188–228); Red: samples obtained with SHARON effluent used as influent NH₄⁺–N ~ 300 mg/L/NO₂⁻–N ~ 300 mg/L (days 229–310)