Fig 3.

Community characteristics of AOB in the sediment microcosms before and after the 8-week incubations, as revealed by 454 pyrosequencing of 16S rRNA genes. (A) Relative abundance of 454 reads affiliated with β-AOB (Nitrosomonas and Nitrosospira). Bars with the same lowercase letter on top were not significantly different (P > 0.05). (B) Neighbor-joining phylogenetic tree of the representative sequences for each AOB 16S rRNA gene OTU in this study with a similarity less than 97% (in bold). Values in parentheses are the sequence numbers representing the indicated OTU. The classification of AOB clusters followed that presented in reference 45. Only bootstrap values greater than 50% are shown. Bar, 2 changes per 100 nucleotide positions. (C) Relative abundance of specific AOB lineages for each temperature.