Degradation of aroclor 1242 dechlorination products in sediments by Burkholderia xenovorans LB400(ohb) and Rhodococcus sp. strain RHA1(fcb).
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.
Rodrigues
Jorge L M
JL
NSF Center for Microbial Ecology, 540 Plant and Soil Science Building, Michigan State University, East Lansing, MI 48824, USA.
Kachel
C Alan
CA
Aiello
Michael R
MR
Quensen
John F
JF
Maltseva
Olga V
OV
Tsoi
Tamara V
TV
Tiedje
James M
JM
D001140:Aroclors / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019117:Burkholderia / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D002713:Chlorine / Q000378:metabolism; D002723:Chlorobenzoates / Q000378:metabolism; D004785:Environmental Pollutants / Q000378:metabolism*; D005818:Genetic Engineering / Q000379:methods; D019015:Geologic Sediments / Q000382:microbiology*; D009876:Operon; D011078:Polychlorinated Biphenyls / Q000378:metabolism; D011995:Recombination, Genetic; D012240:Rhodococcus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism
D001140:Aroclors; D002723:Chlorobenzoates; D004785:Environmental Pollutants; D012989:Soil Pollutants; D002713:Chlorine; C027423:aroclor 1242; D011078:Polychlorinated Biphenyls