Fig. 2.

Phylogenetic analysis of the archaeal amoA gene sequence (ca. 560 bp) obtained from strain MY1. Archaeal amoA genes were amplified using primers AamoAF and AamoAR. The amoA gene sequences from 16 clones randomly selected from the library were identical. Branching patterns supported by more than 50% bootstrap values (1,000 iterations) by means of neighbor joining are denoted by their respective bootstrap values. Cluster groups are denoted at the right based on the origins of reference sequences. “ThAOA” indicates thermophilic AOA lineage. The scale bar represents 5% estimated sequence divergence. Enriched or isolated AOA among the reference sequences are indicated in boldface.