TABLE 2.

Induction of green fluorescence in P. fluorescens A506(pTS) by various compounds^a

Compound	Induction ratio (mean ± SEM)
Benzene derivatives
Ethylbenzene	14.7 ± 0.8
Toluene	14.2 ± 0.5
Chlorobenzene	11.3 ± 3.0
Benzene	11.0 ± 0.7
Styrene	10.4 ± 1.0
Phenol	2.8 ± 0.1
Isopropyl benzene	2.6 ± 0.3
Propyl benzene	2.2 ± 0.4
o-Xylene	2.4 ± 0.2
m-Xylene	1.3 ± 0.1
p-Xylene	1.4 ± 0.3
2-Hydroxy benzoic acid	1.5 ± 0.6
Benzoate	1.1 ± 0.1
2,4-Dinitrophenol	0.6 ± 0.1
Aliphatic alcohols
Ethanol	1.0 ± 0.1
Isopropanol	1.0 ± 0.1
Butanol	1.0 ± 0.1
2-Methyl-1-propanol	0.9 ± 0.1
Alkenes and alkanes
TCE	12.2 ± 1.3
1,2-cis-DCE	8.7 ± 0.3
1,1-DCE	6.7 ± 0.6
1,2-trans-DCE	1.6 ± 0.3
1,1,1-TCE	1.1 ± 0.2
2-Methyl-2-butene	6.5 ± 1.0
n-Hexane	0.9 ± 0.1
Ethylene glycol	1.1 ± 0.1
Cyclohexane	1.2 ± 0.1
Isopentane	1.3 ± 0.3
Polyaromatics
Naphthalene	1.2 ± 0.1
Phenanthrene	1.1 ± 0.1
Biphenyl	1.0 ± 0.3
Other
Catechol	1.1 ± 0.1
Methyl-tert-butyl ether	0.8 ± 0.1
No effector control	1.0

^aInduction ratio is the RFU of an effector-exposed sample divided by the RFU of a no-effector control; no-effector control was arbitrarily set to 1.0. Assay concentrations of effectors were 80 mg ml⁻¹, except for saturated aqueous solutions of phenanthrene (approximately 1 mg liter⁻¹), naphthalene (approximately 10 mg liter⁻¹), biphenyl (approximately 7.5 mg liter⁻¹), n-hexane (approximately 1 mg ml⁻¹), cyclohexane (approximately 55 mg liter⁻¹), equimolar (610 μM) concentrations of the chloroethylenes, 2-methyl-2-butene, isopentane, isopropylbenzene, and propylbenzene (200 μM). All experiments were repeated 3 to 5 times. Values in bold indicate that there was a statistically significant increase (P < 0.05) in fluorescence above that of the no-effector control based on a paired t test.