Phylogenetic tree based on 16S rRNA sequence positions 34–1461 for P. stutzeri and related strains, including the new thiosulfate-oxidizing isolates described in this study. The numbers 1–8 indicate genomovars [32,33]. The tree was rooted with P. aeruginosa strain as outgroup. The scale bar corresponds to 5 substitutions per 1000 nucleotides.