TABLE 3.

Comparison of the ratios of major Aquificales branches in different types of hot springs

Hot spring typea	Temp (°C)	pH	Sulfide (mg liter−1)	No. of clones analyzed	No. of Bacteria OTUs	% of total clones belonging to the following Aquificales branchb				Reference or source
						H	P	J	S
Sulfur mat, Japan	52–72	7.2–8.0	3–6	25	No data	0	0	48	0	33
Sulfur mat, Iceland	67	6.7	12	171	14	0	9	59	0	This study
Pink filaments, OS YNP	84–88	8.3c	0.2c	35	3	0	74	0	0	26
Pink filaments, Iceland	88	6.9	1.7	68	6	1.5	87	1.5	0	Hjörleifsdottir et al., submitted
Sediment, OP YNP	75–93	6.7/7.6d	No data	312	54	0.6	0.6	0	26	16
Chloroflexus mat, Iceland	65–70	8.3	1	123	18	3	1.6	12	0	This study

^aYNP, Yellowstone National Park; OS, Octopus Spring; OP, Obsidian Pool.

^bH, Hydrogenobacter branch; P, pink filament branch; J, Japanese branch; S, sediment branch.

^cInformation from Brock (6).

^dWater/sediment; information from Barns et al. (5).