Activity and stability of a recombinant plasmid-borne TCE degradative pathway in suspended cultures

✍ Scribed by Robert R. Sharp; James D. Bryers; Warren G. Jones; Malcolm S. Shields

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 133 KB
• Volume: 57
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/(sici)1097-0290(19980205)57:3<287::aid-bit5>3.0.co;2-d

✦ Synopsis

The retention and expression of the plasmidborne, TCE degradative toluene-ortho-monooxygenase (TOM) pathway in suspended continuous cultures of transconjugant Burkholderia cepacia 17616 (TOM 31c ) 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 ⅐ mg protein, which is comparable to the rates found for the original plasmid host, Burkholderia cepacia PR1 31 (TOM 31c ). 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.