TABLE 2.

Effects of indole addition to conditioned medium from a tnaA mutant

Strain	Growth conditiona	Mean β-galactosidase activity ± SD (Miller units)b
MT113	LB	299 ± 6
	CM (wild type)	1,116 ± 57
	CM (tnaA mutant)	344 ± 17
	CM (tnaA mutant) + 600 μM indole	1,289 ± 39
	CM (tnaA mutant) + 300 μM indole	1,030 ± 79
	CM (tnaA mutant) + 150 μM indole	736 ± 11
MT114	LB	63 ± 2
	CM (wild type)	252 ± 8
	CM (tnaA mutant)	210 ± 10
	CM (tnaA mutant) + 600 μM indole	320 ± 12
	CM (tnaA mutant) + 300 μM indole	289 ± 16
	CM (tnaA mutant) + 150 μM indole	244 ± 12

^aConditioned medium (CM) was prepared at an A₆₀₀ of = 1.4. 

^bCells were harvested at an A₆₀₀ of 0.35.