Table 5.

Influence of nitrate on total bacteria, cellulolytic and nitrate-reducing bacteria abundance using qPCR technology

	Treatments			SEM	p-value	Contrast1
	0NR	1NR	2NR			PL	PQ
Total Bacteria (log copies)	11.36	11.18	11.21	0.05	0.06	0.06	0.13
R. flavefaciens (%)	0.3463b	0.7889a	0.6600a	0.041	<0.01	<0.01	<0.01
R. ablus (%)	0.0115	0.0185	0.0266	0.003	0.06	0.02	0.9
F. succinogenes (%)	0.0392b	0.2240a	0.2687a	0.052	0.02	0.01	0.29
S. ruminantium (%)	0.2778b	0.6176a	0.4453ab	0.080	0.02	0.30	0.01
C. fetus (%)	0.00003b	0.0002b	0.0015a	<0.001	<0.01	<0.01	0.05
M. succiniciproducens (%)	0.0006b	0.0016b	0.0068a	0.002	0.04	0.02	0.29
W. succinogenes (%)	0.0031	0.0064	0.0041	0.001	0.14	0.21	0.13
V. parvula (%)	0.0001	0.0001	0.0002	<0.001	0.82	0.67	0.66

qPCR, quantitative polymerase chain reaction; 0NR, control; 1NR, 1% nitrate; 2NR, 2% nitrate; SEM, standard error of the mean.

¹P_L is liner tendency; P_Q is quadratic tendency.

Different superscripts in the same row represent significant differences (p<0.05).