Table 2.

Dominant operational taxonomic units (OTUs) that drive the separation of the acetylene treated sediments versus the control sediments.

OTU	OTU count	Phylum	Genus (best hit)
Over-represented in acetylene treatment
9877∗	3738	Proteobacteria	Thioprofundum sp.
9979∗†‡	3313	Proteobacteria	Thiohalomonas sp.
9899∗†	1660	Bacteroidetes	Unclassified
9800∗†‡	1489	Proteobacteria	Pelobacter sp.
9635∗†	1044	Bacteroidetes	Prolixibacter sp.
9960∗†‡	1033	Proteobacteria	Desulfobulbus sp.
9734∗†	1005	Proteobacteria	Thiohalomonas sp.
9918∗†‡	912	Bacteroidetes	Arcicella sp.
9879∗	497	Spirochaetes	Spirochaeta sp.
8638∗†‡	128	Proteobacteria	Desulfobacula sp.
9780†‡	165	Proteobacteria	Pelobacter sp.
9819†‡	98	Proteobacteria	Thioprofundum sp.
Over-represented in control treatment
9878∗†‡	4110	Proteobacteria	Methylomicrobium sp.
9814∗†	3642	Proteobacteria	Desulfosalsimonas sp.
9829∗†	2373	Cyanobacteria	Bacillariophyta sp.
9905∗‡	2328	Bacteroidetes	Meniscus sp.
9921∗†‡	1912	Bacteroidetes	Prolixibacter sp.
9941∗†	1436	Bacteroidetes	Fulvivirga sp.
9937∗†	1347	Bacteroidetes	Roseivirga sp.
9054∗†	607	Bacteroidetes	Owenweeksia sp.
9908∗†‡	560	Proteobacteria	Desulfocapsa sp.
6603∗†	508	Proteobacteria	Neptuniibacter sp.
9633†‡	516	Bacteroidetes	Persicobacter sp.
9608†‡	265	Proteobacteria	Sulfurovum sp.
5645†‡	160	Proteobacteria	Sedimenticola sp.
7286‡	30	Lentisphaerae	Lentisphaerae sp.

OTUs that were in the top 20 of significance in the in the principal components analysis (PCA; ^∗) and LEfSe analyses (^‡), along with those deemed significant by SIMPER(†) analyses are noted for discriminating species.