Table 3.

Taxonomic origin and abundance of hydL genes for [FeFe]-hydrogenase and of hynL genes for [NiFe]-hydrogenase in the PAS metagenomes.

Gene and taxon	PAS-616P	(%)	PAS-821TP	(%)
hydL for [FeFe]-hydrogenase	0.044	100.00	0.057	100.00
Bacteroidetes	0.003	7.49	0.011	19.10
Deltaproteobacteria	0.006	13.04	0.006	10.68
Firmicutes	0.028	64.35	0.029	50.88
Spirochaetes	0.002	3.92	0.004	6.31
hynL for [NiFe]-hydrogenase	0.505	100.00	0.532	100.00
Actinobacteria	0.008	1.68	0.002	0.34
Archaea	0.111	21.98	0.039	7.38
Bacteroidetes	0.008	1.52	0.010	1.87
Betaproteobacteria	0.008	1.68	0.001	0.28
Chloroflexi	0.014	2.72	0.007	1.36
Deltaproteobacteria	0.279	55.19	0.321	60.45
Epsilonproteobacteria	0.000	0.06	0.041	7.63
Firmicutes	0.001	0.24	0.003	0.57
Gammaproteobacteria	0.013	2.51	0.011	2.16

The numbers are fractions relative to those for rpoB¹. The fractions (%) of the total of these are also given.

¹A total of 43,059 and 35,808 rpoB gene fragments were detected in the merged 454 and Illumina assemblies.