Fig. 1.

Phylogenetic tree based on partial amino acid sequences of the pMMO subunit A, deduced from pmoA sequences. Ammonia monooxygenase 1 subunit A, deduced from the amoA sequences of Nitrosomonas europaea, was defined as an outgroup. The deduced sequences of 157 amino acid residues were analyzed by maximum likelihood. Sequences obtained from the S. crosnieri epibiotic community in this study are shown in bold. The initial letters (B and R) of the sequence names indicate the pmoA gene sequence amplified with the primers A189f/mb661r and primers A189f/A682r, respectively. Numbers in parentheses indicate the numbers of clones retrieved from the S. crosnieri epibiotic community before and after rearing for 3 and 12 months, respectively. Sequences consistently obtained from the epibiotic community before and after rearing are shown in red. A bootstrap analysis was performed with 300 resampled data sets. Bootstrap values >50% are shown at branch points. The scale bar indicates 0.3 substitutions per site.