TABLE 3.

Ubiquitous OTUs^a

OTU	Phylum or class	Genus	No. of samplesb	% of sequencesc
OTU1	Alphaproteobacteria	Hyphomonas	14	8.62
OTU3	Alphaproteobacteria	Sphingomonadales, unclassified	8	3.65
OTU4	Alphaproteobacteria	Oceanicola	13	4.47
OTU8	Alphaproteobacteria	Roseibium	9	2.19
OTU10	Alphaproteobacteria	Alphaproteobacteria, unclassified	12	2.09
OTU18	Alphaproteobacteria	Rhodobacteraceae, unclassified	9	1.35
OTU19	Gammaproteobacteria	Gammaproteobacteria, unclassified	9	1.55
OTU28	Bacteroidetes	Balneola	13	0.71
OTU31	Alphaproteobacteria	Labrenzia	12	0.75
OTU33	Alphaproteobacteria	Alphaproteobacteria, unclassified	12	1.23
OTU34	Bacteroidetes	Ekhidna	14	3.83
OTU64	Gammaproteobacteria	Enterobacteriaceae, unclassified	15	0.28
OTU73	Gammaproteobacteria	Gammaproteobacteria, unclassified	12	0.18
OTU77	Alphaproteobacteria	Tistlia	8	0.17
OTU100	Bacteroidetes	Flammeovirgaceae, unclassified	11	0.23
OTU101	Alphaproteobacteria	Alphaproteobacteria, unclassified	8	0.14
OTU107	Bacteroidetes	Flammeovirgaceae, unclassified	8	0.15
OTU129	Alphaproteobacteria	Rhodospirillaceae, unclassified	9	0.07
OTU136	Firmicutes	Veillonella	14	0.08
OTU140	Fusobacteria	Fusobacterium	11	0.09
OTU152	Bacteroidetes	Prevotella	12	0.07
OTU196	Firmicutes	Streptococcus	12	0.03
OTU197	Actinobacteria	Atopobium	10	0.04
OTU198	Alphaproteobacteria	Rickettsia	15	0.08
OTU202	Gammaproteobacteria	Pasteurellaceae, unclassified	8	0.03
OTU227	Firmicutes	Streptococcus	10	0.03
OTU229	Firmicutes	Gemella	10	0.03
OTU246	Firmicutes	Lactobacillus	10	0.02
OTU255	Firmicutes	Staphylococcus	8	0.02
OTU258	Firmicutes	Streptococcus	8	0.01
OTU307	Bacteroidetes	Prevotella	8	0.01
OTU320	Actinobacteria	Mycobacterium	9	0.01

^aOTUs were deemed ubiquitous if they were observed in at least half of all 15 samples.

^bNumber of samples (of 15 total) in which the OTU was detected.

^cPercentage of total sequences across all 15 samples contained within the OTU.