FIG. 6.

Phylogenetic relationships of pmoA deduced amino acid sequences obtained from DGGE bands enriched in the heavy DNA fractions collected from CsCl density gradients for soil samples 32D, 33D, and 34D from Eureka, collected in 2006 and 2007, incubated in the presence of [¹³C]methane with or without NMS medium at 4°C or at room temperature. The tree was inferred by neighbor-joining analysis of 114 homologous positions of deduced amino acid sequence from each band. The ammonia monooxygenase subunit A amino acid sequence from Nitrosococcus oceani (GenBank accession no. AAB57809) was used as the outgroup. Numbers on the nodes are the bootstrap values (percentages) based on 1,000 replicates (values above 70 are presented). The scale bar indicates the estimated number of base changes per nucleotide sequence position. The numbered DGGE bands presented in Fig. 4 are shown in roman (normal) type. Known genotypes are shown in boldface type. GenBank accession numbers are shown after the species in smaller type. Lake Washington is located in King County, Washington state. Transbaikal soda lake is located in the Transbaikal region of Russia.