TABLE 3.

Viable cell counts determined after washing and after 1 h of incubation at pH 4 either with or without 200 μM uranyl acetate^a

Genus	Strain	CFU (washed)b	CFU (without U)c	CFU (with U)
Arthrobacter	FRC-AA1	(1.79 ± 0.48) × 108d	(1.59 ± 0.49) × 108	(1.45 ± 0.49) × 108
	FRC-AA21	(1.53 ± 0.37) × 108	(7.78 ± 0.20) × 107	(6.45 ± 0.38) × 107
	FRC-AA25	2.31 × 108	1.39 × 108	(9.20 ± 0.49) × 107
	FRC-V45	(1.67 ± 0.40) × 108	(9.13 ± 0.15) × 107	(6.85 ± 0.18) × 107
	FRC-X34	1.83 × 108	1.71 × 108	1.07 × 108
	A. histidinolovorans ATCC 11442	(1.57 ± 0.13) × 108	(6.10 ± 0.49) × 107	(4.35 ± 1.04) × 107
Bacillus	FRC-N65	2.99 × 108	(1.12 ± 0.38) × 108	<1 × 104
	FRC-X18	(1.87 ± 0.50) × 108	(3.51 ± 1.14) × 107	4.03 × 105
	FRC-Y9-2	(2.55 ± 0.64) × 107	(3.12 ± 1.05) × 106	<1 × 104
	B. cereus ATCC 14579	(9.70 ± 0.52) × 107	<1 × 104	<1 × 104
Escherichia	E. coli JM109	(8.00 ± 0.37) × 107	(4.65 ± 0.30) × 107	<1 × 104
Rahnella	FRC-Y9602	1.10 × 108	(5.40 ± 0.40) × 107	(1.54 ± 0.92) × 106

^aAt pH 4 U(VI) occurs primarily as the uranyl ion (UO₂²⁺).

^bAll strains were plated immediately following two washes with 0.1 M NaCl at pH 4.

^cStrains were incubated for 1 h at pH 4.

^dStandard deviations greater than 10% are shown.