Ribosomal intergenic spacer analysis (RISA) fingerprints of PCR products amplified with 16S–23S rRNA gene universal primers (38r and 72f) from DNA extracted from soil samples not treated with Atrazine and either inoculated or not inoculated with earthworms (a). PCA ordination of RISA fingerprints generated from DNA extracted from soil samples not treated with Atrazine and inoculated or not with earthworms (S vs. SW) (b), treated with Atrazine (SA vs. SAW) (c), inoculated with Pseudomonas sp. ADP (SP vs. SPW) (d), or treated with Atrazine and inoculated with Pseudomonas sp. ADP (SPA vs. SPAW) (e). The microsites sampled were control soil (Co), surrounding soil (Su), burrow linings (Bu) casts (Ca) and Gut contents (Gu). The variance percentages explained by PCA axes 1 and 2 are shown on each panel on the x- and y-axes, respectively.