Table 3.

Summary of taxa identified in the 16S rRNA gene clone libraries.

Site	Family	Genus	% Total	Representative pure culture match	Accession No.	Similarity (%)	Physiology	Reference(s)
Microbial mat (61 clones)	Gallionellaceae	Gallionella	37.7	Gallionella capsiferriformans ES-2	CP002159.1	96–97	Fe(II) Ox, O2 red	Emerson and Moyer (1997)
	Unclassified Burkholderiales	Aquabacterium	29.5	Denitrifying Fe(II)-oxidizing bacteria	U51102.1	99	Fe(II) Ox, ${\text{NO}}_{\text{3}}^{-}$ red	Buchholz-Cleven et al. (1997)
	Gallionellaceae	Candidatus Nitroga	11.5	Sulfuricella denitrificans	AB506456.1	92	S0/${\text{S}}_{\text{2}}{\text{O}}_3^{\text{2}-}$ Ox, O2/${\text{NO}}_{\text{3}}^{-}$ red	Kojima and Fukui (2010)
	Comamonadaceae	Rhodoferax	8.2	Rhodoferax ferrireducens T118	CP000267.1	92	Fe(III) red	Finneran et al. (2003)
	Gallionellaceae	Sideroxydans	6.6	Sideroxydans lithotrophicus ES-1	CP001965.1	94–96	Fe(II) Ox, O2 red	Emerson and Moyer (1997)
	Unclassified Bacteroidetes	Unclassified Bacteroidetes	6.6	Bacteroidetes bacterium RL-C	AB611036.1	84–94	Fermentation	Qiu and Sekiguchi, unpublished
Puffball (80 clones)	Gallionellaceae	Sideroxydans	15.0	Sideroxydans lithotrophicus ES-1	CP001965.1	97–99	Fe(II) Ox, O2 red	Emerson and Moyer (1997)
	Methylococcaceae	Methylobacter	13.8	Methylobacter sp. BB5.1	AF016981.1	94–96	CH4 Ox, O2 red	Smith et al. (1997)
	Comamonadaceae	Comamonas	11.3	Comamonas sp. IST-3	DQ386262.1	100	Fe(II) Ox, O2 red	Blöthe and Roden (2009)
	Desulfovibrionaceae	Desulfovibrio	10.0	Desulfovibrio putealis strain B7-43	NR–029118.1	99	${SO}_4^{2-}$ red; Fe(III) red	Basso et al. (2005); Lovley et al. (1993)
	Aeromonadaceae	Aeromonas	8.8	Aeromonas hydrophila strain ATCC 7966	X60404.2	98	Fe(III) red	Knight and Blakemore (1998)
	Unclassified Burkholderiales	Aquabacterium	7.5	Denitrifying Fe(II)-oxidizing bacteria	U51102.1	99	Fe(II) Ox, ${\mathbf{\text{NO}}}_{\mathbf{\text{3}}}^{-}$ red	Buchholz-Cleven et al. (1997)
	Rhodocyclaceae	Propionivibrio	7.5	Propionivibrio limicola strain GolChi1	NR–025455.1	97	Fermentation	Brune et al. (2002)
	Bacillaceae	Bacillus	6.3	Bacillus sp. MB-5	AF326363.1	99	Ferm; Mn(II) Ox, O2 red	Francis and Tebo (2002)
	Rhodocyclaceae	Rhodocyclus	5.0	Rhodocyclus tenuis strain DSM110	D16209.1	97	Anoxygenic Phototroph	Hiraishi (1994)
	Unclassified Clostridiales	Blautia	3.8	Eubacterium plexicaudatum ASF 492	AF157054.1	94	Fermentation	Dewhirst et al. (1999)
	Geobacteraceae	Geobacter	3.8	Geobacter sp. strain CdA-2	Y19190.1	96	Fe(III) red	Cummings et al. (2000)
	Methylococcaceae	Methylosarcina	2.5	Methylosarcina lacus strain LW14	NR–042712.1	96	CH4 Ox, O2 red	Kalyuzhnaya et al. (2005)
	Hyphomicrobiaceae	Rhodoplanes	1.3	Alphaproteobacterium Shinshu-th1	AB121772.1	96	Aerobic Heterotroph	Hamaki et al. (2005)
	Comamonadaceae	Hylemonella	1.3	Ottowia thiooxydans strain K11	NR–029001.1	100	${\text{S}}_{\text{2}}{\text{O}}_3^{\text{2}-}$ Ox, O2/${\text{NO}}_{\text{3}}^{-}$ red	Spring et al. (2004)
	Gallionellaceae	Gallionella	1.3	Gallionella capsiferriformans ES-2	CP002159.1	96–97	Fe(II) Ox, O2 red	Emerson and Moyer (1997)
	Crenotrichaceae	Crenothrix	1.3	Methylomonas sp. LW15	AF150794.1	94	CH4 Ox, O2 red	Costello and Lidstrom (1999)

Taxa related to known FeOB and Fe(III) reducing organisms are shown in bold in the Physiology column.