Title: Degradation of aroclor 1242 dechlorination products in sediments by Burkholderia xenovorans LB400(ohb) and Rhodococcus sp. strain RHA1(fcb).

Authors: Rodrigues, Jorge L M; Kachel, C Alan; Aiello, Michael R; Quensen, John F; Maltseva, Olga V; Tsoi, Tamara V; Tiedje, James M

Published In Appl Environ Microbiol, (2006 Apr)

Abstract: Burkholderia xenovorans strain LB400, which possesses the biphenyl pathway, was engineered to contain the oxygenolytic ortho dehalogenation (ohb) operon, allowing it to grow on 2-chlorobenzoate and to completely mineralize 2-chlorobiphenyl. A two-stage anaerobic/aerobic biotreatment process for Aroclor 1242-contaminated sediment was simulated, and the degradation activities and genetic stabilities of LB400(ohb) and the previously constructed strain RHA1(fcb), capable of growth on 4-chlorobenzoate, were monitored during the aerobic phase. The population dynamics of both strains were also followed by selective plating and real-time PCR, with comparable results; populations of both recombinants increased in the contaminated sediment. Inoculation at different cell densities (10(4) or 10(6) cells g(-1) sediment) did not affect the extent of polychlorinated biphenyl (PCB) biodegradation. After 30 days, PCB removal rates for high and low inoculation densities were 57% and 54%, respectively, during the aerobic phase.

PubMed ID: 16597946

MeSH Terms: Aroclors/metabolism*; Biodegradation, Environmental; Burkholderia/genetics; Burkholderia/growth & development; Burkholderia/metabolism*; Chlorine/metabolism; Chlorobenzoates/metabolism; Environmental Pollutants/metabolism*; Genetic Engineering/methods; Geologic Sediments/microbiology*; Operon; Polychlorinated Biphenyls/metabolism; Recombination, Genetic; Rhodococcus/genetics; Rhodococcus/growth & development; Rhodococcus/metabolism*; Soil Pollutants/metabolism