FIG 1.

Proportions or abundances of the amoA gene from comammox and AOB in 21 different environmental samples, assessed by two-step PCR with highly degenerate primers (THDP-PCR) (A) or by quantitative real-time PCR, compared with the abundance of the 16S rRNA gene from total bacteria (TB) (B). In panel A, the positive error bars indicate differences between the two sequencing methods (Illumina HiSeq and MiSeq). In panel B, the positive error bars indicate the standard deviation of three replicates, and the units of the results are copies per gram for soil/sediment/sludge samples, copies per liter for water samples and copies per square meter for leaf surface. An asterisk (*) indicates that the results were under the detection limit. For detailed information about the primer sets used in this analysis, please see Table 1.