Nonrecombinant Genetic Modification of Aquifer Bacteria to Achieve ConstitutiveDegradation of Trichloroethylene

摘要

Aquifer bacteria were isolated for their capacity to predominate followingnutrient enrichment (field application vectors (FAVs)), and screened as hosts for the Tn5 containing, constitutive toluene ortho-monoxygenase (Tom) expressing plasmid: TOM(31c) (which causes the cooxidation of trichloroethylene (TcE)). Tom expression during positive selection in native aquifer sediments contaminated with TCE was determined. Three such FAVs were constructed: NFG-2 (TOM3ic), MFI-l (TOM3ic), and MFG-2 (TOM3ic). All stably maintained TOM3ic and constitutively degraded TCE. Like the original TOM31c mutant strain (Burkholderia cepacia G4 PR131), MFG-2 (TOM31c) was unable to significantly degrade TCE in native