Figure 3: The impact of AgCl colloids on MET-1 DNA analyses. Left panel shows the UPGMA clustering analysis (dendrogram) using the observed PCR-DGGE band patterns generated after exposure to AgCl and control (no Ag), where the L-, M- or H- prefix before AgCl represents 25,100 and 200 mg/L concentrations, respectively. Numbers at the end of the descriptors (1, 2, 3) indicate each of the replicate samples. Mid panel shows the human gut bacterial phylogenetic composition (species level) normalized to the total fatty acids after 48 h exposure to A) 0 (Control), B) 25 (L-AgCl), C) 100 (M-AgCl), and D) 200 (H-AgCl) mg/L AgCl colloids, respectively. Means of the triplicate samples in each treatment (with >1% relative abundance) were used for sequence identity, whereas less abundant species are shown as ‘Others’. The quantity of the total phylogenetic composition reduced in different AgCl treatment groups from control (with no Ag) is shown (%) in the mid panels B, C and D. Right Panel (Panel E) shows multidimensional scaling (MDS) plots of human gut bacterial community composition after 48 h exposure to 0 (Control), 25 (Low), 100 (Medium) and 200 (High) mg/L AgCl, respectively. Arrows indicate the distance of the AgCl- treatment groups from the control with no Ag.