Table 1.

PCR primer sets for this study

Gene	Primers (forward/reverse)	Target group	Amplicon length (bp)	Reference
16S rRNA	530f/1392r	Universal	900	26
	A109f/ARC915	Archaea	800	18, 58
	Ar0023mLF/Ar1530R	Archaea	1,500	36
	27f/1492r	Bacteria	1,500	26
	Bac349F/Bac806R	Bacteria	460	59
	A344F/ARC915	Archaea	570	5, 58
	MX825cm/ARC915	Methanosaeta	90	This study, 58
	MS821c/ARC915	Methanosarcina	90	49, 58
mcrA	MR1mod/ME2mod	Archaea	1,100	This study