A Bacterial Treatment System for the Remediation of Trichloroethylene.
Abstract
14. Abstract A genetically altered bacterium Burkholderia (Pseudomonas) cepacia PR123 and closely related genetic derivatives were tested for bioreactor and in situ trichloroethylene (TOE) degradation. PRi 23 was shown to degrade TOE in a plugged flow bioreactor, but failed to form a stable biofilm under test conditions at Hanscom AFB. Indigenous microorganisms dominated the reactors shortly after inoculation in every instance, despite changes in support matrix and primary carbon source. The continuous addition of the genetically altered bacterium did achieve a significant (>80%) removal of TOE and cis-dichloroethylene from the waste stream at concentrations of 500-800 ugiL, at 0.26 GPM, thus confirming the capacity the constitutively expressed toluene ortho-monooxygenase (Tom) to cooxidize TOE under environmental conditions. For this reason the Tom constitutive plasmid: TOM31c (a kanamycin resistant derivative of TOM), was transferred to two superior biofilm forming bacteria: P. capacia 17616 and P. sp JSl5O, and dominant aquifer bacterium from Wichita KS WS23. These transconjugants also constitutively degraded TOE, but were no more competitive in biofilm reactors than PR123. In column tests >95% of the TOE was degraded in an 8 hour residence time.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1996
- Accession Number
- ADA317277
Entities
People
- Malcolm S. Shields
Organizations
- University of West Florida