Activity and stability of a recombinant plasmid-borne TCE degradative pathway in suspended cultures.
The retention and expression of the plasmid-borne, TCE degradative toluene-ortho-monooxygenase (TOM) pathway in suspended continuous cultures of transconjugant Burkholderia cepacia 17616 (TOM31c) were studied. Acetate growth and TCE degradation kinetics for the transconjugant host are described and utilized in a plasmid loss model. Plasmid maintenance did not have a significant effect on the growth rate of the transconjugant. Both plasmid-bearing and plasmid-free strains followed Andrews inhibition growth kinetics when grown on acetate and had maximum growth rates of 0.22 h-1. The transconjugant was capable of degrading TCE at a maximum rate of 9.7 nmol TCE/min. mg protein, which is comparable to the rates found for the original plasmid host, Burkholderia cepacia PR131 (TOM31c). The specific activity of the TOM pathway was found to be a linear function of growth rate. Plasmid maintenance was studied at three different growth rates: 0.17/h, 0.1/h, and 0.065/h. Plasmid maintenance was found to be a function of growth rate, with the probability of loss ranging from 0.027 at a growth rate of 0.065/h to 0.034 at a growth rate 0.17/h.
Sharp
R R
RR
Department of Environmental Engineering, Manhattan College, Riverdale, New York 10475, USA. RSHARP@Manhattan.edu
Bryers
J D
JD
Jones
W G
WG
Shields
M S
MS
D019342:Acetic Acid / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors; D001709:Biotechnology; D016956:Burkholderia cepacia / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D003227:Conjugation, Genetic; D004785:Environmental Pollutants / Q000378:metabolism*; D015870:Gene Expression; D005798:Genes, Bacterial; D007700:Kinetics; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D010957:Plasmids / Q000235:genetics*; D011995:Recombination, Genetic; D014241:Trichloroethylene / Q000378:metabolism*
D004785:Environmental Pollutants; D014241:Trichloroethylene; D006899:Mixed Function Oxygenases; C093480:toluene ortho-monooxygenase; D019342:Acetic Acid