TY - JOUR
T1 - Rhizoremediation of trichloroethylene by a recombinant, root-colonizing Pseudomonas fluorescens strain expressing toluene ortho-monooxygenase constitutively
AU - Yee, Dennis C.
AU - Maynard, Jennifer A.
AU - Wood, Thomas K.
PY - 1998/1
Y1 - 1998/1
N2 - Trichloroethylene (TCE) was removed from soils by using a wheat rhizosphere established by coating seeds with a recombinant, TCE-degrading Pseudomonas fluorescens strain that expresses the tomA+ (toluene o- monooxygenase) genes from Burkholderia cepacia PR123(TOM(23C)). A transposon integration vector was used to insert tomA+ into the chromosome of P. fluorescens 2-79, producing a stable strain that expressed constitutively the monooxygenase at a level of 1.1 nmol/min · mg of protein (initial TCE concentration, 10 μM, assuming that all of the TCE was in the liquid) for more than 280 cell generations (36 days). We also constructed a salicylate-inducible P. fluorescens strain that degraded TCE at an initial rate of 2.6 nmol/min · mg of protein in the presence of 10 μM TCE [cf. B. cepacia G4 PR123(TOM(23C)), which degraded TCE at an initial rate of 2.5 nmol/min · mg of protein]. A constitutive strain, P. fluorescens 2-79TOM, grew (maximum specific growth rate, 0.78 h-1) and colonized wheat (3 x 106 CFU/cm of root) as well as wild-type P. fluorescens 2-79 (maximum specific growth rate, 0.77 h-1; level of Colonization, 4 x 106 CFU/cm of root). Rhizoremediation of TCE was demonstrated by using microcosms containing the constitutive monooxygenase-expressing microorganism, soil, and wheat. These closed microcosms degraded an average of 63% of the initial TCE in 4 days (20.6 nmol of TCE/day · plant), compared to the 9% of the initial TCE removed by negative controls consisting of microcosms containing wild-type P. fluorescens 2-79-inoculated wheat, uninoculated wheat, or sterile soil.
AB - Trichloroethylene (TCE) was removed from soils by using a wheat rhizosphere established by coating seeds with a recombinant, TCE-degrading Pseudomonas fluorescens strain that expresses the tomA+ (toluene o- monooxygenase) genes from Burkholderia cepacia PR123(TOM(23C)). A transposon integration vector was used to insert tomA+ into the chromosome of P. fluorescens 2-79, producing a stable strain that expressed constitutively the monooxygenase at a level of 1.1 nmol/min · mg of protein (initial TCE concentration, 10 μM, assuming that all of the TCE was in the liquid) for more than 280 cell generations (36 days). We also constructed a salicylate-inducible P. fluorescens strain that degraded TCE at an initial rate of 2.6 nmol/min · mg of protein in the presence of 10 μM TCE [cf. B. cepacia G4 PR123(TOM(23C)), which degraded TCE at an initial rate of 2.5 nmol/min · mg of protein]. A constitutive strain, P. fluorescens 2-79TOM, grew (maximum specific growth rate, 0.78 h-1) and colonized wheat (3 x 106 CFU/cm of root) as well as wild-type P. fluorescens 2-79 (maximum specific growth rate, 0.77 h-1; level of Colonization, 4 x 106 CFU/cm of root). Rhizoremediation of TCE was demonstrated by using microcosms containing the constitutive monooxygenase-expressing microorganism, soil, and wheat. These closed microcosms degraded an average of 63% of the initial TCE in 4 days (20.6 nmol of TCE/day · plant), compared to the 9% of the initial TCE removed by negative controls consisting of microcosms containing wild-type P. fluorescens 2-79-inoculated wheat, uninoculated wheat, or sterile soil.
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U2 - 10.1128/aem.64.1.112-118.1998
DO - 10.1128/aem.64.1.112-118.1998
M3 - Article
C2 - 9435067
AN - SCOPUS:0031985850
SN - 0099-2240
VL - 64
SP - 112
EP - 118
JO - Applied and environmental microbiology
JF - Applied and environmental microbiology
IS - 1
ER -