Table 3. Primers used in the functional gene abundance qPCR assay.

Gene	Forward Sequence	Reverse Sequence		Product size (bp)	Efficiency	Reference
16s rRNA	5’-TAA CCT GGG AAC GCG ATT T-3’		5’- CCA CTA CCC TCT ACC ACA CT-3’	55	111%	[37]
nosZ	5’- AGA ACG ACC AGC TGA TCG ACA-3”		5’- TCC ATG GTG ACG CCG TGG TTG-3’	300	101%	[38]
mcrA	5’- AAA GTG CGG AGC AAT CAC C-3’		5’TCG TCC CAT TCC TGC TGC ATT GC-3’	186	87%	[39]
nirK	5’-TCA TGG TGC CGC GGA CGG-3’		5- GAA CTT GCC GGT GCC CAG AC-3’	326	88%	[40]
amoA	5’- GGG GTT TCT ACT GGT GGT-3’		5-‘ CCC CTC BGS AAA VCC TTC TTC-3’	491	81%	[41]