Phylogenetic relationships of partial 16S rRNA of
the representative OTUs gene sequences recovered from
the 454-pyrosequencing with a relative abundance greater
than 0.1%. E. coli was used as the outgroup taxon. The
Genbank accession numbers (in bold) were obtained from
the 16S ribosomal RNA sequence databases. The scale bar
represents 5% sequence divergence; circles at the branch
nodes represent a bootstrap confidence level of greater
than 70%. A similarity threshold greater than 97% was
used for the same OTU assignment.