TABLE 4.

Diffusible nature of toxic TCE intermediate(s)

2-Hexyne pretreatmenta		% TCS-100 cells able to grow on LB- Tet plates following TCE exposureb
Wild-type G4	TCS-100
Yes	Yes	89.0 ± 8.5
No	No	0.3 ± 0.25
No	Yes	31.5 ± 3.2

^aCells pretreated with 2-hexyne lacked toluene 2-monooxygenase activity and were incapable of TCE transformation. 

^bToluene-grown cells of B. cepacia G4 and B. cepacia TCS-100 were or were not pretreated with 2-hexyne (as indicated). The cells were then mixed in a 9:1 ratio (G4–TCS-100) and exposed to TCE for 30 min. The culturability of the TCS-100 cells within the TCE-treated cell mixtures was determined by colony counts on LB agar plates containing tetracycline (15 μg/ml). All values are the means of three trials ± standard deviations.