Table 4.

Cosmopolitan methanogen OTUs and their significant (p < 0.01) co-occurrent OTUs in all samples

Cosmopolitan	Co-occurrents	Spearman’s ρ	Co-occurrent affiliations	Co-occurrent affiliated phylum	Number of co-occurring samples
(a) OTU23 (Methanocorpusculum)
	OTU74	0.675	Parabacteroides	Bacteroidetes	20
	OTU78	0.722	Porphyromonadaceae	Bacteroidetes	23
	OTU1240	0.628	Bacteroidales	Bacteroidetes	20
	OTU128	0.721	Sphaerochaetaceae	Spirochaetes	22
	OTU64	0.786	Bacteroidaceae	Bacteroidetes	23
	OTU38	0.708	Sphaerochaeta	Spirochaetes	23
	OTU125	0.746	Anaeroplasmataceae	Tenericutes	22
	OTU416	0.840	Sphaerochaeta	Spirochaetes	24
	OTU44	0.720	Candidatus Cloacamonas	Spirochaetes	23
	OTU169	0.826	Treponema	Spirochaetes	25
	OTU137	0.686	Bacteroidales	Bacteroidetes	23
	OTU48	0.749	Bacteroidaceae	Bacteroidetes	22
	OTU92	0.672	Bacteroidales	Bacteroidetes	20
	OTU339	0.659	Bacteroidales	Bacteroidetes	21
	OTU47	0.661	Lachnospiraceae	Firmicutes	21
	OTU91	0.637	Treponema	Spirochaetes	23
	OTU303	0.651	Anaerovorax	Firmicutes	20
	OTU844	0.722	Sedimentibacter	Firmicutes	24
	OTU8	0.604	Bacteroidales	Bacteroidetes	26
	OTU72	0.859	Sphaerochaeta	Spirochaetes	27
(b) OTU14 (Methanosaeta)
	OTU52	0.666	Porphyromonadaceae	Bacteroidetes	25
	OTU96	0.653	Syntrophus	Proteobacteria	17
	OTU749	0.657	Bacteroidales	Bacteroidetes	23
	OTU12	0.689	Candidatus Cloacamonas	Spirochaetes	17
	OTU87	0.742	Syntrophomonas	Firmicutes	28
	OTU66	0.724	Bacteroidales	Bacteroidetes	23
	OTU119	0.703	Clostridia	Firmicutes	23
(c) OTU142 (Methanoculleus)
	OTU327	0.610	Crenarchaeota	Crenarchaeota	22
	OTU8	0.635	Bacteroidales	Bacteroidetes	32
	OTU38	0.619	Sphaerochaeta	Spirochaetes	21
	OTU137	0.714	Bacteroidales	Bacteroidetes	23
	OTU169	0.648	Treponema	Spirochaetes	22
	OTU91	0.660	Treponema	Spirochaetes	22
	OTU454	0.628	Candidatus Cloacamonas	Spirochaetes	24