Table 1.

Phylogenetic affiliations of the microbial reads identified at the genus level (at >0.1% abundance) by pyrosequencing of the 16S rRNA genes in the original oil-degrading methanogenic (planktonic) culture and after the inoculum was incubated in a sandstone-packed column.

Original enrichment culture		Sand-packed column culture
Taxon (genus)	% of sequence reads	Taxon (genus)	% of sequence reads
Smithella	27.57	Methanobacterium	55.90
Methanosaeta	25.48	Pseudomonas	16.33
Methanoculleus	22.95	Methanocalculus	4.91
Methanocalculus	5.52	Eggerthella	3.52
Sedimentibacter	5.23	Halomonas	3.20
Desulfotomaculum	3.27	Methanoculleus	2.88
Desulfobacterium	2.14	Clostridium	2.37
Kosmotoga	1.97	Desulfovibrio	1.28
Thermanaerovibrio	1.79	Sedimentibacter	1.14
Petrotoga	0.95	Sphingomonas	0.94
Desulfuromonas	0.53	Methanosaeta	0.84
Syntrophorhabdus	0.48	Ralstonia	0.69
Desulfovibrio	0.38	Methylobacterium	0.53
Methanolinea	0.25	Geovibrio	0.46
Spirochaeta	0.22	Sediminibacterium	0.39
Tissierella	0.20	Methanomethylovorans	0.37
Leptolinea	0.17	Desulfuromonas	0.34
Fastidiosipila	0.16	Pelomonas	0.30
Anaerovorax	0.12	Tepidanaerobacter	0.27
Others	0.64	Burkholderia	0.25
		Bacillus	0.23
		Brevundimonas	0.21
		Spirochaeta	0.21
		Microbacterium	0.18
		Alicyclobacillus	0.18
		Methanofollis	0.16
		Thauera	0.16
		Koelreuteria	0.16
		Rhodococcus	0.14
		Thiobacillus	0.11
		Bradyrhizobium	0.11
		Others	1.26