Table 2. Bacterial taxa present in various cleanroom samples as determined by pyrosequencing method.

	Number of MOTUs from:								Number of pyrosequences from:
Taxa	SAF cleanroom floor (GI-36-4)		SAF–GSE (GI-36-3)		Bldg 144 cleanroom floor (GI-42-1)		Bldg 144 GSE (GI-42-2)		SAF cleanroom floor (GI-36-4)		SAF–GSE (GI-36-3)		Bldg 144 cleanroom floor (GI-42-1)		Bldg 144 GSE (GI-42-2)
	As is	PMA	As is	PMA	As is	PMA	As is	PMA	As is	PMA	As is	PMA	As is	PMA	As is	PMA
Actinobacteria	25	1	161		48	8	155	3	350	2	1685		84	106	578	15
Armatimonadetes					3		1	1					6		1	1
Bacteroidetes	8		36		39	5	66	3	108		208		2483	60	403	8
Verrucomicrobia					2								5
Chloroflexi	1		6				9		4		44				24
Deinococcus-Thermus			7		5		13				26		7		40
Acidobacteria	4		1		1		3	2	112		55		1		30	67
Firmicutes	11		24	1	11	5	24	2	157		250	2	16	30	109	10
Fusobacteria	1		1				2		1		1				2
Gemmatimonadetes					2								2
Nitrospirae					1		1						1		1
Planctomycetes			1		2		2				1		2		4
Proteobacteria
Alpha	41	2	100	8	186	41	168	16	606	11	1154	52	7335	1058	2478	121
Beta	9		22		39	14	46	2	100		464		879	296	525	42
Delta	1		1		3		2		36		5		6			5
Gamma	19	2	26	2	67	23	35	5	357	3	231	6	4784	479	1094	239
Unidentified					9	2	4							155	2	31
Spirochetes	1								1
Unidentified division
SC4				3			4				23				6
TM7			1		1						2		1
WPS-2					2								2
Unclassified bacteria	4		32	5	26	10	36	8	8		112	27	145	165	103	25
Total	122	4	425	17	447	108	571	42	1783	14	4318	89	15914	2196	5434	528

Abbreviations: Bldg, building; GSE, ground support equipment; MOTU, molecular operational taxonomic unit; PMA, propidium monoazide; SAF, spacecraft assembly facility.