FIG. 2.

Phylogenetic tree showing the relationships of SJA sequences and bacterial 16S rDNA sequences. M. concilii (X16932) and Thermoplasma acidophilum (M20822) were used as an outgroup. The number of additional clone sequences belonging to the individual SJA clone families is given in brackets. Environmental rDNA clone sequences obtained from a contaminated aquifer in an independent study (5) are indicated by the prefixes WCHB1, WCHA1, or WsCH. Branching points supported by bootstrap values >74% are indicated by filled circles. Open circles indicate branching points, which are supported by bootstrap values between 50 to 74%. Branching points without circles were not resolved (bootstrap values, <50%). The scale bar represents 10% sequence divergence.