FIG. 3.

Phylogenetic tree based on parsimony analysis of recA gene sequences for deep-subsurface and type strains of Arthrobacter species. For the deep-subsurface strains, the soil sample identifier and stratum from which they originate are indicated. Abbreviations and symbols are as in Fig. 2. The tree is rooted using S. ambofaciens as an outgroup. Numbers at the nodes indicate the percentages of occurrence in 100 bootstrapped trees; only values that are 50% or greater are shown.