TABLE 1.

Studies included in this meta-analysis and operational parameters.

	Reactor configuration	Amount of reactors	Substrate	Temperature	Platform	Primers	Study
WTAR	UASB	4	Brewery	Mesophilic	Roche 454 FLX	27F-338R	Werner et al., 2011
	IC	1
	EGSB	4
	UBF	1	High-strength pharmaceutical		Illumina MiSeq	8F-338R	Ma et al., 2017
	UASB	2	Pulp and paper		Roche 454 GS-FLX	357F-926R	Shu et al., 2015
		1	Starch
		1	Juice
		2	Municipal and campus domestic sewage
		1	Potato	NA	Illumina MiSeq	515F-806R	Zhu et al., 2017
		1	Poultry slaughterhouse		Ion 318TM	577F-924R	Delforno et al., 2016
		1	Vinasse	Mesophilic	Roche 454 FLX	515F-806R	Bovio et al., 2019
		3	Dairy
		1	Malting		Ion Torrent PGM	520F-802R
		1	Paper mill	NA	Illumina MiSeq	515F-806R	Sposob et al., 2018
	AnaEG	1	Cassava, potato, maize starch			341F-805R	Qin et al., 2018
	IC	1	Ethanol processing wastewater	Mesophilic			Qin et al., 2019
	AnaEG	1
STAR	–	1	Municipal solid wastes		Roche 454	27F-518R	Cardinali-Rezende et al., 2016
	Plug-flow	2	Dairy cattle manure suppl. with cheese			27F-519R	St-Pierre and Wright, 2014
			Cattle manure with ice cream waste
	Complete mix	1	Cattle manure with oil waste
	CSTR	1	Food waste-recycling wastewater	Thermophilic		787F-1492R	Lee et al., 2016
		2	Primary and biological sewage sludge	Mesophilic	Ion Torrent PGM	515F-806R	Hao et al., 2016
		3	Mixed sludge		Illumina MiSeq	515F-805R	Liu et al., 2017
			Thin stillage
			Agricultural waste
		1	Maize silage		Roche 454 GS	27F-519R	Lucas et al., 2015
		7	Cattle manure		Illumina MiSeq	515F-806R	Li et al., 2015
	USR	1
		1	Swine manure
	CSTR	11
		4	Sewage sludge		Roche 454 GS-FLX	787F-1492R	Shin et al., 2016