Table 3. Relationship between the functional gene copy numbers, the 16SrRNA gene copy and the ratios between the genes.

Gene ratio	Period 1 (Autotrophic with NO3 −)	Period 2 (Heterotrophic with NO3 −)	Period 3 (Autotrophic with NO2 −)
qnarG/q16S rRNA (×100)	0.4±0.1	0.2±0.0	0.1±0.0	ns
qnapA/q16S rRNA (×100)	0.5±0.1	0.4±0.0	0.1±0.0	**
qnirS/q16S rRNA (×100)	42.0±15.9	90.0±23.9	52.2±3.4	*
qnirK/q16S rRNA (×100)	0.5±0.0	1.0±0.0	0.3±0.0	***
qnosZ/q16S rRNA (×100)	5.4±0.2	2.8±0.3	4.2±0.7	**
(qnarG+qnapA)/qnosZ	0.17±0.01	0.19±0.01	0.06±0.01	***
(qnarG+qnapA)/(qnirS+qnirK)	0.02±0.01	0.01±0.00	0.01±0.00	*
(qnirK+qnirS)/qnosZ	7.99±3.29	32.45±8.88	12.80±2.10	**

The values show the mean and standard deviation (SD) of two independent measurements. The statistical significances between the treatments were calculated using one-way ANOVA or Kruskal-Wallis test depending on the normality of the data. ns, not significant;

^* p<0.05;

^** p<0.01;

^*** p<0.001.